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New oil catch can may be finally showing what is wrong with my engine.

EXT4ME

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As a follow up to the recent installation of the oil catch can, I can say as of right now, after having this device installed for the short period of time it has been working, I probably have found the source of some of the problems with my engine.

The problems I am referring to are a random tapping at cold start up that I tried to address by having several broken exhaust manifold bolts and both exhaust manifold gaskets replaced.

While this repair may have had limited effect, it certainly did not stop the tapping altogether.

A second issue I have been dealing with has been a very slow loss of coolant.

Using a radiator pressure tester I bought from Harbor Freight, I was able to locate and fix several external coolant leaks, all of which were fixed by tightening or replacing several hose clamps.

Even with all of the leaks that I was able to identify and repair, I was still presented with a very slow loss of coolant.

Whenever I was doing other maintenance on my truck, I would often install the pressure tester and leave it in place in hope of locating another external leak.

The pressure always very slowly dropped while I was testing, but no visible coolant leaks were ever seen.

I am now convinced the slow drop in coolant pressure was due to the internal coolant leak, possibly due to a leaking head gasket.

The next issue was a strange accumulate of some type of debris both inside the bottom of the oil pan and most recently inside the bottom of the oil filter.

This strange substance was first discovered around May 3, 2019, when the engine had about 9,000 miles less than it does now.

On the day this stuff was first discovered, I was in the process of having a new oil pump installed in my engine to address some issues with low oil pressure.

Previous to this day, I had already had a new oil pickup tube with included o-ring installed to address low oil pressure.

There were no obvious signs of abnormal debris in the oil pan sump during the replacement of the oil pick up tube and o-ring.

This repair did appear to improve the oil pressure, but the low oil pressure returned before the next oil change.

I had a new oil pan installed shortly afterwards to address some pretty good oil leak issues, including a persistent oil leak I have had at the location where the external oil cooler line set attaches to the oil pan.

The two bolt holes where the oil cooler adapter is installed had long since been stripped out so much that they could no longer be repaired enough to hold the adapter.

During the replacement of the old oil pan, no strange debris was noted in the sump of the old pan.

I feel the existence of the internal coolant leak was either non-existent or extremely small, at this point in time.

I now think the coolant leak may have begun between the time the oil pick up tube was replaced and the time between when the new oil pan was installed and the new oil pump was soon afterwards installed.

Each time the oil pan was dropped, I had the oil changed and a new oil filter installed.

Some of these oil changes occurred during a shorter time and mileage period than I normally would have done.

The last time the new oil pan was dropped was to install a new oil pump to address the latest drop in overall oil pressure.

It was thought that the OEM oil pump was worn out and due to be replaced.

I had dropped the EXT off at my mechanic and was expecting the job to be completed some time the next day.

I later received a text with pictures and a request to swing by the shop to see what they had discovered when they dropped the oil pan.

They scrapped out the gunk and placed it in the upper potion of the oil pan to get a better picture.

At best guess, this stuff covered a layer on the bottom of the sump approximately 1/2" deep.

It is extremely likely that this junk was blocking the inlet of the oil pickup tube and was being drawn into the oil pump, as well.

The accumulation of this stuff probably explains why I was seeing better oil pressure for a while after the replacement of the oil pick up tube and o-ring, but the oil pressure began to drop a short time period afterwards.

Below are some pictures of this gunk we found in the oil pan.

IMG_3540-01.jpg


IMG_3541-01.jpg


IMG_3542-01.jpg


IMG_3539-01.jpg


part0_28Small29.jpg


Remember, you are seeing the inside of a brand new oil pan with less than a normal 7500 oil change interval on the oil.

More likely, there was closer to 4000 miles on this oil/Lucas mixture.

At the time we first discovered this debris, I had convinced myself that this stuff was a result of me having listened to my mechanic, and in a weak moment, I had allowed a quart of Lucas Synthetic Oil Stabilizer to be added to this oil change.

I now no longer to believe that to be true, but I will continue to refrain from using any additives to my oil.

I do not feel there is any benefit.

At the very next oil change, we ran a bore scope up into the oil drain hole on the oil pan to see if there was any new debris in the oil pan sump.

There was none to be seen, adding to me being convinced the debris was a result of the Lucas.

At no point did we bother to cut open an oil filter.

I now think that may have been a good idea.

With the installation of the new oil pump, my engine has consistently had much better oil pressure at all temperatures and RPM's.

I have noted that, even though I had not previously noted any valve train noises, the engine did appear to run a bit quieter and power did seem to come on smoother and just better.

After the installation of the new oil pump and the successful repairs of the engine oil leaks, which also included replacing the rear main seal and rear main seal plate, I was now able to return to my normal oil change interval, which usually meant changing the oil and filter at around 7500 miles.

The oil change I just did occurred at about 20% oil life remaining according to the oil monitor.

Probably around 5000 miles.

Sometime between the last oil change and this most recent one, I began to notice the cold start tapping coming from the engine.

Upon examining the exhaust manifold bolts, I found a couple of the bolt heads missing and obvious signs of some exhaust leaking around the gaskets.

I opted to have all of the broken bolts extracted and new bolts and gaskets installed.

There was some improvement in the cold start tapping, but it never totally went away.

The cold start tapping was random and would not be there for several days and then return for several days running.

Sometimes, the tapping would last for a very few seconds and other times would take as long as 5 minutes before totally going away.

Someone here had mentioned that they had changed their oil and they had installed 10W-40 oil and they reported a reduction in their valve train noises.

I have always run Mobil 1 5W-30 and a NAPA Platinum oil filter.

This most recent oil change, I decided to use Mobil 1 10W-40 High Mileage to see if that would help with my leaking down lifter(s) issue.

Much to my pleasure, the tapping stopped a couple of days after the oil change and has not yet returned.

I now attribute the cold start lifter tapping stopping due to the coolant contaminated oil being finally flushed out of the lifters.

I had set the oil filter off to the side and did not use my oil filter cutting tool to open the filter right away.

A couple of weekends later, I changed the oil in our GMC Acadia and I saw the EXT filter sitting there where it had been draining for the past week or so.

When I got out my filter cutter and cut open the NAPA Platinum oil filter from the EXT, I was shocked to see the bottom 1/2 inch or so of the oil filter can was covered in some strange debris.

This debris was somewhat like the previous debris we had found in the sump of the oil pan a while back.

This mess would not pour out of the bottom of the oil filter and I had to scrape it out with a screw driver.

The top layer resembled a thick, black tar-type substance while the layer closest to the bottom of the oil filter appeared to be almost like a gritty dark fudge brownie looking material.

The pleats of the filter material were covered in thick, black stuff that did not run off. as the pleats sat in the drain pan.

I recalled that the engine oil that I drained was black, but it drained from the engine without any noticeable clumps.

I let the oil drain from the engine for quite a while.

I did not feel the need to use the bore cam to view inside the sump.

I wish now I had and I will be doing so from now on, at least until a fix to stop the coolant leak has been accomplished.

Recently installing the oil catch can was a result of someone here indicating I might be seeing the stuff in the oil filter due to a high level of crankcase blow by gases.

This sounded reasonable to me and I figured installing the catch can might yield some clues.

Boy, did it.

With running with the oil catch can for around one tank worth of fuel, it would appear my engine has some sort of internal coolant leak.

I'm leaning toward a leaking head gasket, but with my luck, it may be even more serious.

When I first checked the dipstick on the catch can, I saw what looked like water condensation on the stick.

I went ahead and opened the catch can and found 2 oz. of a brownish-pink liquid in the bottom of the can.

Now, bear with me when it comes to colors, as I do have some color deficiency in my eyesight.

I do check my engine oil with great regularity and the level of the oil has always appeared to be steady and full.

The appearance of the oil has always looked to me to be normal, with no apparent cloudiness or signs of it having the classic milkiness associated with coolant being mixed into the oil.

However, I had my wife take a look at the oil and the engine coolant and she indicated the clear, un-milky oil on the engine dipstick had a slight pink hue to it.

She indicated the contents of the oil catch can was a milky brown color with a pinkish hue to it.

Oh, joy.

So, it is now my assumption that the coolant leak (hopefully from a leaking head gasket, but possibly from a cracked head or a crack in the engine block) is allowing coolant to leak into the crankcase.

This coolant, when mixed with the engine oil, it not yet producing the classic milky engine oil we have come to look for.

Instead, there is a sort of tar like debris that settles in the bottom of the oil pan sump and is also pumped through the oiling system of the engine by the oil pump.

Some of this debris appears to be caught in the oil filter and settles in the bottom of the filter.

I am assuming at this point, that with the contamination of the engine oil with the coolant, the viscosity of the engine oil drops significantly and that was allowing some of the lifters to loose their normal oil charge and therefore need to be pumped back up at cold engine start.

The randomness of the cold start tapping may be a result of whether the lifter was sitting on top of the cam lobe or if it was resting on the cam flat.

If it was on the lobe, the added pressure on the lifter in that position may have forced more of the oil/coolant mixture out of the lifter while at rest.

Sitting on the flat of the cam would not press on the lifter near as much, pushing less oil out of the lifter, resulting in a much faster pump up.

So, here is where I am at, this is not the best time for me to send the truck to the shop to have a large tear down in search for a coolant leak.

I plan to monitor the situation and take steps on my own to try and better pinpoint where the coolant leak is coming from.

I am going to go ahead and change my spark plugs and perform a compression test and possibly run my bore scope into each spark plug hole to see what the inside of each cylinder and piston top looks like.

Seeing any indication of abnormally clean spark plugs or piston tops may indicate a coolant leak at that location.

I have not noticed any abnormal steam vapor coming from the tail pipe, but it is winter time, so normal condensation may be masking something in that area.

I do not smell coolant anywhere, as a rule.

I am going to check and empty the oil catch can as it does appear, at the very least, some of the coolant contaminated oil is getting vaporized and is being drawn into the PCV system.

I will capture what I can and hope there isn't a lot more coolant staying in suspension.

I intend to change the oil on a much more accelerated change interval, hopefully keeping the fresh oil from going bad soon and causing additional damage.

Also, I will be taking other vehicles when possible to attempt to reduce the amount of time the engine is running.

While not always possible, I can at least try.

Obviously, the EXT will not be used for long distance traveling until this problem is taken care of.

I know this was a long drawn out post, as many of mine are, but I felt I needed to work through my thought processes on this matter and try to get some documentation for myself.

Perhaps some of you find this interesting, perhaps not.

I welcome any insight anyone may have.

I figure the best case will be if I can get the truck into the shop and let the pros do what they can do.

Worst case, I wait a minute too long and the engine gets wasted.

I can assure you that I will take action as soon as I am able.

I'll try to keep the situation updated and I might update the original post if I think of more clues, information or better time frames.

I'm am really pleased with my decision to install the oil catch can.

Perhaps the clues it has given will finally put these issues to rest.

Thanks for reading.
 
Compression test results will tell you everything you need to know about head gasket.

How much coolant are you losing over how much time?

I mean head gaskets tend to be pretty noticible and engine runs for crap the entire time and smokes etc.
They tend to get worse as you drive and well... they tend not to be minor.

Now cracked head can be very slight issue and leak is very small and takes long time to require fill up.

Cylinder leaked down test may help here but you need to know if valves are good up front.


As for gunk in oil - Looks like GLOBs of silicone or caulk sitting in pan.
Have not seen that before as coolant in oil tends to turn it to coffee color whip cream espcially when engine is running.

Now if for some reason you have a coolant leak into oil pan when engine is off (Cannot think of one) then you would get some different mess in the pan..

I dunno... if I had to drive this daily I would remove heads and have them checked out. and while they were off check cam, lifters and push rods.
 
ygmn said:
Compression test results will tell you everything you need to know about head gasket.

How much coolant are you losing over how much time?

I mean head gaskets tend to be pretty noticible and engine runs for crap the entire time and smokes etc.
They tend to get worse as you drive and well... they tend not to be minor.

Now cracked head can be very slight issue and leak is very small and takes long time to require fill up.

Cylinder leaked down test may help here but you need to know if valves are good up front.


As for gunk in oil - Looks like GLOBs of silicone or caulk sitting in pan.
Have not seen that before as coolant in oil tends to turn it to coffee color whip cream espcially when engine is running.

Now if for some reason you have a coolant leak into oil pan when engine is off (Cannot think of one) then you would get some different mess in the pan..

I dunno... if I had to drive this daily I would remove heads and have them checked out. and while they were off check cam, lifters and push rods.

Thank you very much for your reply.

Some very good thoughts here and things I will certainly take into consideration.

I agree that a compression test may yield some good clues.

The amount of coolant loss may be a couple of ounces a week, depending upon the amount of time the truck is driven.

I do not drive the truck a great deal some weeks and sometimes not at all for days on end.

The truck runs REALLY, REALLY WELL.

That's one of the reasons this is so hard.

It does not smoke or pass any unusual amounts of water vapor.

It idles smoothly and pulls like an angry bull and runs like a scalded cat, when asked to.

There are no signs of any discharge on the ground around the tail pipe and there is no smell of coolant that I can sense.

A leak down test was not something I had considered.

I can see where that may also yield some good information.

I can not for the life of me remember where any silicone or gasket making material would have been applied to the engine.

I watched all of the repairs while the oil pan and rear main seals and rear main seal plates were installed and the only sealer I remember being used was applied only to the corner of the oil pan gasket, and that was a small amount.

The picture may not clearly show, but the gunk in the oil pan was a dark, thick gelatinous substance.

Almost like a shiny dark greasy Jello.

Nasty.

I completely agree with you and I have always looked for the milky stuff in the engine oil, but there was none when I changed the oil and there was none in the oil filter.

Just black oil came out of the drain and out of the oil filter.

I still have the old oil in a couple of milk jugs waiting to go to be disposed of.

It's just black without anything having visibly settled out while it's been sitting there.

No layers of anything.

Unfortunately, my situation now is I do not have the money or means to have the heads pulled.

If I could do it myself, I would.

But, now is not a good time.

When I do get a chance to have the heads pulled, I had already planned to have the cam, lifters and pushrods checked and probably just replaced for good measure while we are there.

Thanks again for your comments.

I believe we are like minded.

(y)



 
That looks like oil sludge, but I agree try a compression test first it will tell you allot about the status of your motor
 
MS03 2500 said:
That looks like oil sludge, but I agree try a compression test first it will tell you allot about the status of your motor

The mystery is the oil sludge wasn't there when the new oil pan was installed a couple of thousand miles before the picture was taken.

And the several times before these pictures were taken and the old oil pan was removed, there was no such sludge.

Why the huge amount of sludge in such a short period of time?

We initially thought that perhaps the one time use of the Lucas was to blame by perhaps "cleaning" the sludge from within the engine.

I no longer think that as I have chosen to not use any additives to my oil since then and also since that time I have been made aware of what is actually in the Lucas product.

I am beginning to think that whatever went bad that caused the sludge in the pictures is now getting worse.

Now, I just need to figure out what is happening and see if I am going to be able to get it fixed.
 
I think there are places you can send your oil off to have it analyzed for $20 or $30.  It may be worth sending a sample to have it analyzed.
 
So, last night we took the EXT to a Super Bowl party with a group of friends.

The trip to their house was around a 70 mile round trip.

Other than that I had driven almost a 1/2 tank of fuel in my daily driving since I had last emptied out the first 2 oz of fluid from the catch can cup.

I am thinking maybe somewhere around 200 miles or so since the cup was emptied.

This morning, I checked the catch can dipstick and found the level of fluid was starting to show on the bottom of the dipstick.

I went ahead and unscrewed the cup and found it to be about as full as the last time I checked it.

Here are a couple of pictures showing about 2 oz of the fluid in the cup.

IMG_4112_28Small29.JPG


IMG_4113_28Small29.JPG


For a better view of the total of 4 oz I have collected so far, here are a couple more pictures of the fluid in a measuring cup.

normal_IMG_4114_28Small29.JPG


normal_IMG_4115_28Small29.JPG


When emptying the cup, I found the lowest level of this fluid had already began to get thicker than the top two thirds or so.

It was all the same color, but the bottom third would not pour out of the cup on it's own and when I ran a flat blade screwdriver along the bottom of the cup, the screwdriver tip left a clear mark in the remaining fluid that stayed for a while.

I have no way of knowing how much of this fluid my engine has been dealing with over the past several months, but I am certain that now that I have the catch can installed, I am going to now have to check and empty the cup fairly often.

I am not getting a very good feeling about this, at all.

 
frito said:
I think there are places you can send your oil off to have it analyzed for $20 or $30.  It may be worth sending a sample to have it analyzed.

I am familiar with the work of this place:

Blackstone Laboratories

I am thinking about changing the oil again shortly and sending in a sample.

One of the things they check for is coolant contamination in the oil samples, as well as a bunch of other things.
 
EXT4ME said:
I am familiar with the work of this place:

Blackstone Laboratories

I am thinking about changing the oil again shortly and sending in a sample.

One of the things they check for is coolant contamination in the oil samples, as well as a bunch of other things.
Most likey worth doing.  I hate to say it, but those pictures really look like coolant contamination.
 
Coffee and cream come to mind....
 
ygmn said:
Coffee and cream come to mind....

That's what I thought, too.

Yet, a nice coffee and cream would have been much more soothing.

:laugh:
 
EXT4ME said:
That's what I thought, too.

Yet, a nice coffee and cream would have been much more soothing.

:laugh:
I'm guessing that the engine built up sludge over time with the 7500 mile oil changes (but I would think that Mobil 1 would be resistant to overheating and congealing).  Then you put the Lucas cleaner in and it did what it was supposed to.  Now - what was in the top of the engine is going down into the bottom.  Have you removed the valve cover to inspect the top part of the engine - this is where sludge usually lives.  How long do you know the maintenance history on this vehicle?  Could a previous owner have sludged up the engine and you're just now getting it out?

If it was mine I would put more Lucas or Seafoam, or whatever you like into it and keep changing oil/filter every thousand miles or so until it's clean.  It's not good.  You might consider removing the engine and a partial teardown for sludge removal, if it's in the top of the engine as well.  Not good to keep washing it through the oiling system.
 
2004Slickside said:
I'm guessing that the engine built up sludge over time with the 7500 mile oil changes (but I would think that Mobil 1 would be resistant to overheating and congealing).  Then you put the Lucas cleaner in and it did what it was supposed to.  Now - what was in the top of the engine is going down into the bottom.  Have you removed the valve cover to inspect the top part of the engine - this is where sludge usually lives.  How long do you know the maintenance history on this vehicle?  Could a previous owner have sludged up the engine and you're just now getting it out?

If it was mine I would put more Lucas or Seafoam, or whatever you like into it and keep changing oil/filter every thousand miles or so until it's clean.  It's not good.  You might consider removing the engine and a partial teardown for sludge removal, if it's in the top of the engine as well.  Not good to keep washing it through the oiling system.

The engine now has 235K on it and it had 116K when I bought it back in 2012.

Since I have owned it, I have only used Mobil 1 5W-30 with NAPA Platinum oil filters.

A typical oil change has been between 7500 and 7800 miles.

Never more than that and sometimes less.

When the new oil pan was installed in one of our attempts at resolving some ongoing oil leaks, I allowed my mechanic, on his recommendation, to install one bottle of Lucas Pure Synthetic Oil Stabilizer with 5 quarts of Mobil 1 5W-30 motor oil and a NAPA Platinum oil filter.

The old oil pan had been dropped several times previously and no such sludge was ever seen.

After the new oil pan was installed, my ongoing issues with low oil pressure had me decide to have the oil pump replaced.

The oil pick up tube and o-ring assembly has already been replaced in an effort to address the low oil pressure issue.

That fix was very temporary.

So, I purchased my new oil pump and dropped my truck off to the shop to have it installed.

It has always been my standard practice to always have new oil and filter installed any time the lower engine is opened up.

The engine oil at that time had only been in the engine for a couple of thousand miles, if that long.

That's when they dropped the oil pan and found the sludge in the pictures.

On the very next oil change, we ran the bore scope up into the oil pan drain hole and we saw no sludge.

I have not used the bore scope on subsequent oil changes and I wish I had.

I will be using the bore scope and also cutting open the oil filters for the foreseeable future.

The engine is now currently loaded with Mobil 1 10W-40 High Mileage and a NAPA Platinum oil filter.

My oil pressure, while very good after the installation of my new oil pump, is right now even better.

I am attributing that mostly to the clean oil that is only now lightly contaminated with coolant, as opposed to the previous oil and the gunk filled oil filter I just removed.

I am now absolutely convinced that the Lucas had zero effect on the build up of sludge that you see in the pictures of my oil pan.

And for anyone that is convinced that the sludge shown was because one bottle of Lucas had somehow "cleaned" my engine, then I think that is a good enough case for anyone to NOT use that product unless you started using Lucas from the very first oil change.

Otherwise, if you started using Lucas later in the engine's life then you better plan on dropping the oil pan to see what got cleaned out and be ready to do it again and again.

That sludge was not coming out of the oil pan on it's own.

It had to be physically scrapped out and the oil pan had to be cleaned with brake cleaner to get it all out.

The technical sheet for the Lucas on their own web site has no mention of any cleaning properties for their product.

An independent oil analysis of the Lucas product straight out of the bottle showed no real beneficial additives in the product.

The conclusion from several unbiased technically based (not average user opinions) articles was that adding products like this does nothing to improve the lubrication properties of quality motor oil.

At the very least, most, if not all of these types of additives will actually reduce the protective additive packages of the original base engine oil being used.

When added to normal engine oil, you will also change the viscosity of your main oil if the viscosity of your main oil is not the same as the viscosity of the additive you are choosing to use.

But, I am not here to knock any products like Lucas.

If someone feels these products does good things for them, then more power to them.

The empirical data I have seen for myself shows there is no benefit, so I choose to not use it.

I am convinced that the addition of the Lucas caused no harm.

And I am also thoroughly convinced the Lucas did not clean anything inside my engine, especially in the short period of time it had to work, and therefore did not contribute to the sludge seen in the pictures.

Now back to the engine.

I had personally removed and cleaned and installed new valve cover gaskets in one of my efforts to address the oil leaks previously mentioned.

I saw nothing unusual when I had the valve covers off.

A cursory cleaning of the valve covers was all that was required.

No cleaning of the rockers or anything in that area was required.

Care was used to prevent any dirt from entering the exposed engine.

The work I had done on the valve covers was before the sludge was found in the oil pan and no sludge there was seen at that time.

I do, however, plan to remove the valve covers in the very near future and see what differences I may encounter now.

I am not expecting good things this time around.

After emptying the cup yesterday and finding the goop in the bottom of the cup starting to thicken as it did, I am suspecting that the sludge we saw in the pictures is a result of the coolant in the oil pan that had time to congeal into the sludge and the dark color is a result of being in constant contact with the dark motor oil in the sump of the oil pan.

The debris and goop I found in the bottom of the cut open oil filter looked a lot like the sludge from the oil pan.

So, I am thinking that coolant mixed oil just landed in the bottom of the oil filter and settled there until it got too thick to move on.

If the engine goes to the shop, I hopefully expect a leaking head gasket repair, but maybe worse.

I might go for a head replacement if we confirm a cracked head, otherwise a new engine may get installed.

I don't do junk yard stuff.

Or maybe it just gets sold before it totally craps out.

I dread any of these options.

In a perfect world, I can find a way to afford to get my truck fixed and then move on down the road quite a ways before the next disaster hits.

I do not have the means or health to perform a major engine tear down on my own.

Thank you for your reply.

Good observations and I really appreciate it.



 
A little light Internet reading this afternoon has yielded some interesting information.

I found this page to have some good information.

As we all know, the hit and miss of information on the Internet can be challenging when trying to come up with any real answers.

Sometimes, it is difficult to even formulate the correct question to ask.

I did stumble across a few forums where people were talking about coolant contamination in engine oil.

More than one of these forum posts were made by people that had found thick, black glop in their oil pans and they were seeking observations from others about what they had seen in cases of coolant contamination in the engine oil.

So, I am not the only one to have seen this.

While we all are familiar with the classic milkshake looking oil and coolant mixture, the difference here may actually be what happens when DEXCOOL and oil are mixed.

That might explain a few things.

I was expecting a milkshake when I was actually being served a black tar brownie, instead.

Interesting.
 
Ugh, no good man.  I wish upon you a simple leaking head casket and nothing more.
 
Appreciate the good thoughts.
 
More research yielded some more information.

Someone linked to this Youtube video about testing for blown head gaskets.

I ordered a chemical test kit for my own curiosity.

I haven't seen any obvious signs of engine exhaust leaking into the coolant system.

I feel my coolant is making it's way more directly into the crankcase somehow and not being washed past the piston rings.

I picked up a new set of spark plugs and will run some compression tests to see what is going on there.

I will pop off the valve covers and see what I can see there, as well.

The engine just runs too good to have a bunch of coolant spraying into a cylinder or two.

And no appreciable water vapor coming out of the tailpipe, either.

No misfires.

There was a different set of forum posts that described the black sludge I am seeing and one of the solutions indicated the possibility of a couple of head bolts that lose their torque.

This poster indicated he found a couple of specific head bolts that were about half as tight as they should have been on each head.

Coolant was leaking into the area of the valve covers and would then drain down into the crankcase from there.

I think taking off the valve covers and following his testing techniques might be worth the effort.

Either to confirm or deny.

This poster offered up some ways of testing for coolant leaks through the head area by lowering the coolant level and pressurizing the system then listening for air leaks through the valve covers.

I'll go ahead and take the valve covers off to get a better eye on things.

Seems reasonable and easy enough to do.

I hope to do some testing over the next week or so.

I've got nothing else I can do for the foreseeable future.

Maybe I'll get lucky and figure out what's going on.

Can't hurt to try.
 
Hope that yields some positive findings.

One other thing to consider.  I can't remember if I read it in a recent Rock Auto newsletter or on my Suzuki forums.  Do you have an engine oil cooler?  If I'm not mistaken, this person was losing coolant but not seeing the milky oil.  Turns out there was a crack in the internal.componenf of the cooler allowing the two to mis.  I'm sure this is a long shot but wanted to throw it out there just in case.  I wish I could remember where I read it so I could link to it for you.
 
frito said:
Hope that yields some positive findings.

One other thing to consider.  I can't remember if I read it in a recent Rock Auto newsletter or on my Suzuki forums.  Do you have an engine oil cooler?  If I'm not mistaken, this person was losing coolant but not seeing the milky oil.  Turns out there was a crack in the internal.componenf of the cooler allowing the two to mis.  I'm sure this is a long shot but wanted to throw it out there just in case.  I wish I could remember where I read it so I could link to it for you.

Interesting observation.

And one I am happy to hear about.

This is one of the reasons I started this thread.

To reach out and see what others may have come across.

As a matter of fact, my engine DOES have an external oil cooler.

I just received from Amazon, on Thursday, an OIL PORT ADAPTER Cooler Delete Block Off Plate LS1 LS LSX Gasket Pan 551621.

My new oil pan originally came with the same OEM delete adapter that I venture most Avalanche engines come with.

But that part has been long gone for some time now.

All EXT's came with the auxiliary engine oil cooler as standard equipment and I would imagine, Avalanches with optional towing packages did as well.

My plan is to disconnect my oil cooler lines but leave them installed in the truck.

I am on my second set of oil cooler lines sets since I have owned this truck.

They are a real bear to uninstall and reinstall, so I will seal off the ends and just leave them in place for now.

If the oil cooler in the radiator tank proves to be the source of the coolant leak, I will most likely reinstall the oil cooler lines when I replace the radiator.

I will disconnect the cooler line ends at the radiator and I'll flush out both of the lines and the cooler inside the left side of the radiator.

Then I will watch for coolant leaks coming out of the radiator oil cooler ports.

With any luck, I will see a coolant leak from the in-tank oil cooler.

Wouldn't that be nice?

However, with the oil pressure in my engine reaching a high of over 75 PSI at WOT and running over 40-45 PSI at idle and the radiator only reaching 15 PSI, I would think I would be seeing some oil in the coolant surge tank, which I am not.

At this point, I am still thinking my coolant leak is coming at some point that is not pressurized.

Either a cracked head or block, a head gasket leaking at a coolant passage and not at a cylinder seal point, or possibly at the point of an untorqued head bolt.

Disconnecting the oil cooler and testing the radiator for leaks will be fairly easy to do and the engine is not going to be overly stressed (as if it ever really is) until this problem is solved.

Thanks for your insight and please feel free to pass along anything else you might come across.

(y)
 
Here is a video from South Main Auto showing the coolant leak at the head.

He does mention that the Castech heads are not the only ones that go bad.

I am not certain if I have Castech or not.

At first glance, this one seems to be closer to the symptoms I am seeing.

I just have a feeling this is how the coolant is getting into my crankcase.

So, my valve covers are definitely getting pulled soon.

Strangely enough, I am almost hoping for some head cracks like are shown in this video.

And then, I find a link to this document: #06-06-01-019B: Information on Gradual Coolant Loss
Over Time with No Evidence of Leak Found - (Jun 12,
2007)
.
 
frito said:
Oh yeah, Arrgh, argh, argh, argh (doing my best Time Allen impersonation)  >:D

That would be me, sir.

:laugh:
 
EXT4ME said:
Here is a video from South Main Auto showing the coolant leak at the head.

He does mention that the Castech heads are not the only ones that go bad.

I am not certain if I have Castech or not.

At first glance, this one seems to be closer to the symptoms I am seeing.

I just have a feeling this is how the coolant is getting into my crankcase.

So, my valve covers are definitely getting pulled soon.

Strangely enough, I am almost hoping for some head cracks like are shown in this video.

And then, I find a link to this document: #06-06-01-019B: Information on Gradual Coolant Loss
Over Time with No Evidence of Leak Found - (Jun 12,
2007)
.
I think you're on to something.  (y) I love SMA video channel.  I just recently discovered it but it has become my favorite channel.  He often has to deal with crazy little northern thing called RUST.  I think I need to buy some of his swag to support the channel.
 
frito said:
I think you're on to something.  (y) I love SMA video channel.  I just recently discovered it but it has become my favorite channel.  He often has to deal with crazy little northern thing called RUST.  I think I need to buy some of his swag to support the channel.

I watched his videos back when I replaced my CV shafts and it really gave me some good insight.

Since then, I have watched many other SMA videos on various topics.

Even things that are totally unrelated to any vehicle I own.

I felt like I have learned quite a bit.

I like that guy.

(y)

 
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