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Interesting Website GM Piston Slap

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ultravorx

Full Member
Joined
Nov 16, 2002
Messages
360
Location
New Britain, CT
www.pistonslap.com Has some very interesting points about the problem. As far as my truck goes, after reading the problems that occure with piston slap. I may have it pretty bad. :6: Mine does sound like a diesal on startup, does have a knock to it(dealer has heard it and know there is a sound saying that its normal)

So question? All the people who dont have piston slap, are their trucks abnormal? If so, can I please have an abnormal truck

It also says you may get less that stated/expected gas mileage. That may be the case for me with my 6mpg city/10 highway. I just though it was because i have a 2500, but it may be related to the piston slap. Well, that just more info i can use in my case with the BBB.
Frank
 
Very interesting, I occasionally get a piston slap on cold start up, 1 or 2 knocks the most, wow this sounds like long battles with gm
 
"Normal" yes, but that still doesn't make it "right". There is at least one person in a Silverado thread on another Site who has 100k miles with the piston slap/cold start knock and has not experienced any engine problems.
 
Normal or not, it is the only thing about my truck I dislike. ?My truck makes this noise (16K miles) almost everytime I start it regardless of temperature. ?
I do think it affects the resale value of my truck. ?Would you buy a car that makes a ticking noise on startup? ?If you were looking to purchase a used Avalanche and had 2 identical ones sitting side by side, which one would you purchase? ?The one that sounded like a Diesel on startup or the quiet one? :-[
 
My engine(20,000miles) goes tick,tick,tick for about 5 min then seems to sound normal,dlr said normal on start up for valve lifters to make noise, hummm.
 
I have just developed this problem at slightly under 14,000 miles. So far, it only occurs when the temps are below 40dg, and is gone in a few seconds. The dealer told me this is normal. He also said it has been addressed in the 2003 engines. Regardless of whether this is "normal" or not, I would walk right on past any used car for sale that made this racket in my presence. I have had numerous small block Chevy powered vehicles over the last 25 years and non of them made this "normal" sound.
 
like you said, the problem, should be addressed in the 03', thats why i may consider one if its offered to me.Because i really like the truck, and i really dont want to go to ford or dodge, but i may have too if this(problems from day 1) doesn't get resolved.
Frank
 
avalanchecrazy said:
Normal or not, it is the only thing about my truck I dislike. ?My truck makes this noise (16K miles) almost I start it regardless of temperature. ?
I do think i t affects the resale value of my truck. ?Would you buy a car that makes a ticking noise on startup? ?If you were looking to purchase a used Avalanche and had 2 identical ones sitting side by side, which one would you purchase? ?The one that sounded like a Diesel on startup or the quiet one? :-[
Click to expand...
You just don't let any prospective buyers (or Dealer) start it up cold.
 
ultravorx said:
like you said, the problem, should be addressed in the 03', thats why i may consider one if its offered to me.Because i really like the truck, and i really dont want to go to ford or dodge, but i may have too if this(problems from day 1) doesn't get resolved.
Frank
Click to expand...
I have read that it has been and I've also read that it hasn't been fixed on the '03's. ???
 
With all of the problems I have had with my AV, I am glad this is not one of them - at over 33K miles, I doubt it would start now
 
Hey gang,

I have an '02 Av 2500 that also suffers from the nasty slap. My previous 99 3/4 Chevy with the 7.4 Vortec had it, as did my father's Pontiac with a 3100 V6! Come to think of it, every GM car I have owned in the past 10 years has had it to some degree or another. Most recently, I decided to skip my regular 3K oil change as the manual suggests a much longer interval and also, the truck with inform you when it needs it. Well, I only got to about 4K when the "Check Engine Oil Level" light came on. When I did, I could not find any oil registering on the stick at all!!

Okay, this is definitely a problem. No way on earth anyone should pay in excess of 40K for a rig that burns or leaks oil with 17K miles on it. I will join the fight against GM....

Watch your oil, boys....
 
Hey all,,,

If you have an issue with this that really bugs you, articulate it clearly with your service center, and they will help you... If one doesn't, then try another... If you are burning oil above what GM defines as acceptable, then you will be helped...

All of the problems I have heard so far, can be addressed at dealer level... But some dealers are pains in the rump, and that could go with any problem... So a lot of your satisfaction depends on your service dept...

Heck, I'd rather not drive a Dodge with trannies dumping at 30-40K, or a Ford with trannies dumping at 50-60K ... ?There's issues everywhere with any new vehicle... If they were engineered to be perfect 100% of the time, they would be out of most folk's price range...

I have had nothing but exemplary service from my dealership, and have created a repor with them, rather than fight with them...

And if GM is handing out 6/100K powertrain warranties, for customers, that's pretty good service...

In the end, I think GM builds the best truck and car on the road... (at least within my price range... )


I love my avalanche... It is the best truck I've owned... It's utility can't be matched, and a Ford doesn't even compare in ride quality... My brother in law has a King's Ranch 4x4, and a Navigator ... No comparison

:B: All the way !

LOL

11H
 
Well, for the first time this morning, I heard the piston slap on the Av :6:. It seemed to be right in line with what I read - starting somewhere in the 20K mile range and lasting for 20-30 seconds after cold start. It was short lived but it was certainly noticeable :(.

So look who has joined the piston slap club :rolleyes:!
 
Let them know about it, they will probably want to do an oil consumption test to start out diagnosing piston slap. They will perform an oil change for you. Once you pick up your truck , CHECK THE OIL LEVEL. I was getting screwed by my dealer, he overfilled the oil by a quart. Make sure yours is level, this way it will be an accurate test.
Frank
 
Well, I guess I have a piston slapper!!! I can hear it on start up. Thenas I excelarate for the first 5-10 seconds...only with a cold engine though
 
What that site is saying, the tick-tick-tick is not piston slap...

I hat the little tick in my last truck, and I always thought it was a crummy lifter... but then I was told that was piston slap.... The site is saying the following "death knock" I heard one day was piston slap.

This was in my old 4.3, which was NOT listed on the site...? Did they forget it??

I fired it up one Cold COLD day, and hear BANG BANG BANG BANG BANG - like someone is taking a hammer and smashing my block. I thought I cracked a manifold or was ready to throw a rod. It was VERY LOUD. I sat there scared, thinking of what the heck to do, and it just suddenly cleared up in about 20-30 seconds.

That truck always had power issues... always had oil comsumption issues... always got crap for gas mileage.

This knock started at around 90K on the clock.

I traded the truck in.
 
Okay, I just listened to the sound clip on the site, and that IS what my "tick tick tick" sounded like... ?It's that "tinny" "hollow" metallic tapping sound. ?It wasn't as loud as this, but had the same type of sound to it. ?It did this since day 1.

This death knock I had was like 5 times louder... like my piston was punching a hole in the head.
 
CoAvZ71 said:
Well, for the first time this morning, I heard the piston slap on the Av :6:. ?It seemed to be right in line with what I read - starting somewhere in the 20K mile range and lasting for 20-30 seconds after cold start. ?It was short lived but it was certainly noticeable ? :(.

So look who has joined the piston slap club ?:rolleyes:!
Click to expand...

Well, since the day I made that post, I haven't heard piston slap on the Av ever since :). I suppose the warming temperatures outside might have something to do with it.
 
Saw this in another forum and thought it was interesting:

Here is the scoop on CSK (Cold Start Knock). The main problem, as you may know, is that these pistons are not as tall as they could be but that is done to reduce weight. The result is a rocking of the piston in the bore untill things warm up and expand to the designed size. Ford first began having problems with this and scuffing on the skirts 10 years ago. They came to us with this problem and we developed a "solid film lubricant" coating that solved the problem and has been in production on all Ford V-8 and V-10 engines along with selected V-6 engines for more than 9 years now. We finally got the GM business last year and all of the V-8 engines now have coated skirts since about 10 months ago. GM is well satisfied with the results. No, this coating does not contain Teflon or PTFE. There are several lubricating pigments in the formula that hold oil in the surface of the coating. It is applied by the piston manufacturers (3) using either an automated pad print or silk screen method. They are then cured in an oven. I do not have any knowledge as to the potential problems with the knocking engines made before the coated pistons were adopted but I would think it is not a longevity issue. Enjoy your new quieter engines.


~bekind

 
bekind . . . thanks for the informative post. There's sure lots of discussion going on on this on both the truck boards and the Corvette boards. The two concerns discussed are the noise and long term reliabilty issues. I can live with the noise - my Av with 20k miles on it ticks too - but I do worry about long term wear as high impact metal to metal contact on the cylinder walls can't be a good thing. IMO, that's where the jury is still out, and where alot of the overinflated rhetoric on the internet comes from. The piston coating sounds like a reasonable fix if it holds up well - meaning not just through the warranty period! It'll be interesting to see how this all unfolds over time.
 
bekind said:
Saw this in another forum and thought it was interesting:
We finally got the GM business last year and all of the V-8 engines now have coated skirts since about 10 months ago. GM is well satisfied with the results.

~bekind
Click to expand...


Curious as to when this was written so I could figure out approximately when GM started with this. If it pans out, we should be able to check the born-on date and find out if we are within the time frame of the "fix" or not.

Thanks for the post!
 
docopharm said:
Curious as to when this was written so I could figure out approximately when GM started with this. If it pans out, we should be able to check the born-on date and find out if we are within the time frame of the "fix" or not.

Thanks for the post!
Click to expand...

Me too!!!
 
Saw this on another Site RE: GM Buying back "Knockers:. www.forbes.com/business/newswire/2003/11/14/rtr1148802.html
 
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