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Low Oil Pressure

sanchezm

Full Member
Joined
Mar 2, 2013
Messages
14
Location
DeWitt, Michigan
Hello All,

I am new to this club and don't know how to post messages yet.  Hopefully I'm posting this message correctly.  I have owned my used 2007 Avalanche for over two years now and am just starting to have mechanical problems with it.  It is the LT model and has 53,000 mile on it.  The check engine light came on a few days ago and the dash text read "oil pressure low stop engine" along with warning chimes to get my attention.  I pulled over and called my mechanic.  He told me that as long as I did not hear any metal against metal sounds that the oil was indeed getting to the top of the engine, and that no damage would be done.  I drove it to him, he attached his snap-on code scanner and it did not throw an error code for him, which he thought was odd.  So he suggested that I change the oil pressure sending unit on the engine, which is a common problem with this engine according to him.  I did my own research on the internet before becoming a member here and found that this is indeed a common problem with this engine.  And that there was a 50/50 chance this would solve my problem.  So the next day I replaced the oil pressure sending unit (not fun), but it made no difference.  Now he thinks it may be the oil pressure release or relief valve (don't remember exactly which one he said), but won't know for sure until he conducts more electrical and mechanical tests on the engine.  My question is, has anyone else experienced this kind of problem, know more about it, or have any advice?  If this is something I can do myself I will try, in order to save some money, if not I will pay my mechanic to do the work.  Thanks for any input I can get on this.

Mark
 
Sanchez= First you need to put a manual pressure gauge on the sender and make sure you have pressure. An oil pressure failure is very serious. It actually does not take much oil to keep an engine lubricated. But cam bearings and lifters are your most critical components. If your pressure relief is jammed open then you are not getting any filtration. But you need to see your pressure first. Do not drive it till you get this fixed is my suggestion.

Avalon
 
Thanks for your reply, I appreciate it. I will be taking the vehicle to my mechanic tomorrow morning to manually check the pressure and conduct more tests.  I'll post the results.  Thanks again.

Mark
 
Hello All,

Since joining the club and posting my problem I have some good news, for now.  I figured what's the harm in starting the truck and see what happens if I take it for a drive.  As long as I have oil pressure a don't hear funny noises, what's the worst that could happen?  So I started it up and all was well, oil pressure up and no funny engine noises.  Just the check engine light on the dash.  Drove down to my mechanic and to see what he thought.  He checked the code with his scanner and again it threw no code for him.  He suggested that I get the engine oil nice and hot and do an oil change.  The dash showed 33% oil life left.  Maybe there was some sludge build up or the oil filter wasn't functioning properly.  He also said that he does not trust the "change oil soon" dash indicator to know when it's time to change the oil.  He still goes by the old fashion way of going by recorded mileage, instead of letting the computer tell you.  Any ways I went home after some joy riding and changed the oil.  I didn't notice anything out of the ordinary with the oil or filter.  After the oil change I took another ride and everything seemed to be fine again, except that the check engine light was still on.  So the next day I went to AutoZone to connect their scanner to it and it threw a code regarding the oil pressure sending unit I had replaced the week before.  So I had them clear the code, which turned the check engine light off.  All seems to be well again and I hope it never happens again.  But it all leaves me wondering, what was the real cause of my problem?  Was it a faulty oil pressure sending unit or did the oil and oil filter change solve the problem.  This is still a mystery, but at least things are back to normal and it wasn't as serious as first thought.  Just wanted to pass along my experience to the club and forum members.

Mark
 
I have been told by many mechanics and you can read about it from other users on this site, that the unit often goes bad. I think it would still be freaky though to drive around with oil pressure at zero regardless. lol
 
Guys, I have some information to pass along that may or may not help some of you with similar issues, regarding the fluctuating oil pressure gauge and replacing the oil pressure sending unit.  I again experienced the low oil pressure issue on 2/21/2014 which produces the red dash light, check engine light, and text warning on the dash.  I immediately went to my local Chevy dealer for diagnostics and was told to replace the oil pressure sending unit.  Which I had already done almost exactly a year ago.  I was also told to replace the metal screen filter GM part number 12585328, which is down inside the hole where the oil pressure sending unit is attached.  It is a small cylinder shaped metal and plastic filter the diameter of a pencil and approximately one inch long.  I believe this is what gets clogged up with residue over time and causes the oil pressure gauge to malfunction and throw a computer warning code.  I also believe that it is not always the sending unit itself that is bad and needs to be replaced, but this filter instead.  It cost me $6.02 out the door for the part which you can only get from a dealer.  Or from an on line dealer, plus shipping and handling for about the same price.

Just wanted to share this new information that no one else seemed to address, regarding the replacement of the oil pressure sending unit.  I'm not looking forward to this project, but it has to be done again.  I will also replace the oil pressure sending unit while I'm at it because I don't want to do this job again for a long time!
 
When I took it to the dealer and the service tech connected the scanner, it did throw the code to replace the oil pressure sending unit.  I am going to replace the tiny filter I mentioned in my earlier post today, and think that will resolve the low oil pressure issue.  I'm almost certain that my old oil pressure sending unit was not bad at all.  It was this filter being clogged and not functioning properly.  Not looking forward to it at all and it is very cold outside.  May have to use a propane heater in the garage on for this project.
 
Update - Replaced the filter last weekend and it made all the difference, in a good way.  Everything is back to normal and the oil pressure gauge is functioning properly again.  I will be replacing this filter every 50,000 to 60,000 miles as part of routine maintenance.  GM should have this part included as something that should be replaced at regular intervals in the owner's manual too.  I need to buy a spare for next time, while I'm thinking about it.
 
I just had the low oil pressure warning this morning. Does the metal screen filter GM part number 12585328 apply to a 2010 5.3 flex fuel Avalanche?
 
Guys, I have some information to pass along that may or may not help some of you with similar issues, regarding the fluctuating oil pressure gauge and replacing the oil pressure sending unit. I again experienced the low oil pressure issue on 2/21/2014 which produces the red dash light, check engine light, and text warning on the dash. I immediately went to my local Chevy dealer for diagnostics and was told to replace the oil pressure sending unit. Which I had already done almost exactly a year ago. I was also told to replace the metal screen filter GM part number 12585328, which is down inside the hole where the oil pressure sending unit is attached. It is a small cylinder shaped metal and plastic filter the diameter of a pencil and approximately one inch long. I believe this is what gets clogged up with residue over time and causes the oil pressure gauge to malfunction and throw a computer warning code. I also believe that it is not always the sending unit itself that is bad and needs to be replaced, but this filter instead. It cost me $6.02 out the door for the part which you can only get from a dealer. Or from an on line dealer, plus shipping and handling for about the same price.

Just wanted to share this new information that no one else seemed to address, regarding the replacement of the oil pressure sending unit. I'm not looking forward to this project, but it has to be done again. I will also replace the oil pressure sending unit while I'm at it because I don't want to do this job again for a long time!
You could have saved the $6.02. Take that f****** metal screen oil filter and throw it right in the trash. Don't rerplace it, get rid of it. I have three engines all with that sending unit code and all three were rectified by discarding that oil filter. It does nothing and will only clog up again before you're done with the truck. Unless you like pulling the intake on your truck just get rid of the cursed thing.
 
Brendan @ crazed performance has figured it out and has all the solutions to the AFM abomination of an engine. You MUST check out his videos on you tube if you want all the answers to all the questions you've ever had regarding these AFM engines. He is spot on with everything and backs it all up with tests and performance reviews and technical data. This guy is not a BS'er nor a know it all, but he does know the AFM GM engine like the back of his hand. In fact, he even calls out GM on a number of occasions to which GM has no rebuttal for cause they know they f***** up big time with these engines and Brendan has it all figured out. There are solutions to this engine, I've done them and they work.
 
Brendan @ crazed performance has figured it out and has all the solutions to the AFM abomination of an engine. You MUST check out his videos on you tube if you want all the answers to all the questions you've ever had regarding these AFM engines. He is spot on with everything and backs it all up with tests and performance reviews and technical data. This guy is not a BS'er nor a know it all, but he does know the AFM GM engine like the back of his hand. In fact, he even calls out GM on a number of occasions to which GM has no rebuttal for cause they know they f***** up big time with these engines and Brendan has it all figured out. There are solutions to this engine, I've done them and they work.
This thread is ~5 years old.
 
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