View Full Version : Pistonslap problems?


digitalcaddie
10-22-08, 03:04 PM
If you go to pistonslap.com you can read up on all the troubles that GM had with matching pistons and cylinders in their truck/suv engines until '03 (although some people claim GM still doesn't have the problem fixed) and I was wondering if anyone had any comments/problems. How many miles were on your truck when you first had problems? Is there anything I could do to prevent this from becoming a problem? My engine is in good shape and quiet now with 63k on it, but I don't want to turn the thing into a diesel in the next year or so. Please let me know. GM claims this doesn't affect the performance of the engine, but if the piston is rattling around/scraping the side of the cylinder, how could it not cause problems?? That part doesn't make sense to me and appears like GM issued that statement simply bc they didn't want to fix thousands of engines.

digitalcaddie
11-11-08, 12:58 PM
I'm surprised no one has replied. After visiting fullsizechevy.com (another good forum for Escalade owners), it appears the 6.0 Vortec has more piston slap issues than the 5.3 Vortecs. I can't believe GM used different pistons for the Vortecs put into the Cadillacs compared to Chevy/GMC, but that's about the only reason Cadillac owners wouldn't have these problems. Any insights here?

cadillac_al
11-16-08, 10:01 AM
This is the first I've heard of it. It sounds like a crap shoot. If random pistons are put in random cylinders there is a fair chance that plenty of engines will be fine and some others may not be. Since these are mostly truck engines it's possible that some of these engines may have to actually work hauling loads where Cadillacs just haul groceries. If yours isn't knocking yet then it is probably one of the good ones. My old old 76 truck has had piston slap for years and I have always been ready to change the engine on a moments notice. It's nice to know that GM doesn't consider it a serious problem. I would be upset though if I had a newer truck with piston slap.

I could only find one picture of a piston on pistonslap.com, but it looks like the skirt is smaller than the top of the piston and wouldn't even touch the cylinder walls. It must be an optical illusion or something. My brother has had 3 GM trucks (5.3's) since 2000 and works them on the farm with no problems or noises so I think the majority of the engines are ok.

With high school graduates getting dumber and dumber, GM probably had a hard time finding people that could do math and measure bores and pistons so they had to simplify the process. It's all a numbers game; if the number of defective engines is small enough then it can be considered acceptable.

dkozloski
11-19-08, 06:34 PM
The piston slap vs. GM furor is nothing more than shyster lawyers trying to drum up a class action suit they can cash-in on.

ewill3rd
11-19-08, 10:08 PM
Amen to that.
Pretty tired issue :yawn:

Go live your life. Stop letting other people's problems affect you :D
Hungry lawyers (as if there were such a thing) want you to get worked up about a problem you don't even have.

digitalcaddie
12-07-08, 01:02 PM
Yea, who knows. I've got two co-workers who have this problem. One has an 02 Silverado with the 5.3 and the other has an 01 Burban with the same engine I believe. The guy who owns the Suburban bought the truck new and the thing has slapped since 5k miles. He has 80k on the clock now and isn't too concerned about the problem since it goes away after 30 secs or so. After looking at several chevy forums there are a lot of people with trucks that have this problem, but no one has said their engine failed due to this issue. Its just annoying... Maybe GM is right that it doesn't affect the longevity of the engines, but I don't know how it couldn't.

dkozloski
12-09-08, 01:04 AM
All engines with forged pistons have piston slap because there is no way to control the heat expansion 90deg to the piston pin. To keep the engine from seizing up they have to fit loose when cold thus slap. No harm results. Lower performance engines have cast pistons that incorporate a steel cast-in strut that controls the clearance but are nowhere near as strong and are much heavier.