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Leaks, Smoking, Etc...any Conclusions?


SM 2005
Full Member
Jun 11, 2002
I'm trying to draw some reasonable conclusions from all of the good information posted by owners regarding some of the more major Avalanche issues such as leaks (midgate and otherwise), engine smoking upon start-up, and other issues that seem to be less than 'isolated'. It would seem natural to want to try to group the problems into a window of build dates, but then there are plenty of examples of people with Avs from this "window" (if one exists) who have had zero issues (ie. gandolphxx, perhaps a bad example b/c of all of his mods?).

I'd appreciate some thoughts and theories here...Are the leaks quality control, design, or a combination of the two? The smoking issue seems to be a design issue (PCV valve), yet its occurrence seems isolated; I would expect all with the "bad" valve to be affected but this is not the case. I know that there are many, many variables with something complex like an auto and thats why I am asking for opinions and educated speculation.

On a more objective front, does anyone know if these and other issues have little-by-little been addressed in manufacturing, or is GM treating them as isolated and handling in the service departments (in other words, were the first Avs to roll off the line identical to recent ones)? Are there any known anticipated modifications to the '03's to address the issues?

None of the issues will change my decision to purchase, but, depending on when I buy, I could be on the '02/'03 fence. For '02's, I may wish to try to stick to specific build dates, not that I think I will have much choice as they will become more scarce the longer I wait.

Thanks for your input.
Well as far as the build date timing issue.....you may not be able to choose for a whole lot longer. Anything a dealer has in stock is basically all he is going to have for '02's.

He might have a few yet to be delivered but I wouldnt count on it.

And for the leaks and etc. I would have to say the leaks are a fluke.....somewhat.

There are a few variables that need to be looked at regarding the leaks. Some have leaks that are like Niagra ( not viagra ) and some like myself have only noticed leaks that may have been caused by improper closing of the midgate or bed cover panels.

And as for the smoking I have had no smoking problems at all yet ( have almost 16,000 miles on it ).

My build date is 7/01 and I noticed a small amount of water in the cab last week. Then I read somewhere that sometimes after you have the window out and the cross bar is lowered it doesnt reseat properly sometimes. I reclosed the cross bar and midgate and this weekend I had no leaks in the cab. And if I dont push my panels in securely I will get some leaks....but not much.

IMO I would go for getting yourself an '02. For a few reasons.....dont know how important they are to you but to me some of these are important.

Alot of the standard options on '02 are going to be extra options on '03...ie the trailering package.

There are going to be some new gadgets added from the EXT...ie Rear audio seat controls....dont know about you guys ( and gals ) but I dont like the front passanger to be able to touch my radio let alone the people in the back.

I believe all of the problems that are in an '02 are capable of showing up in the '03's.

Either way you will be happy with the AV.

All of this is my $.02
Great questions... Sorry, honestly I can't help too much.

I just want to vent a bit...

I had A LOT of problems with my Blazer. I also had a fair amount of mods done to it. EVERY-SINGLE-THING that went wrong with it, I'd hear someone say, "If you left it alone, that probably wouldn't have happened." :8:

I had problems with my sending unit. Everyone blamed me for lifting it.

I had problems with the tranny falling out of OD and never hitting third on occasion - that was either the lift of the PP3. :rolleyes:

There were definitely problems which were brought about by some of my mods like driveline vibes, blowing front driveshafts, and exhaust cracking/deteriorating - but don't let a few mods fool anyone into thinking that the mods are the root cause of any problems you have with your truck! :)
While some 02's have had problems (I have had absolutely none with mine). The same will be true of )3's, some will have problems, some will not. They may have some of the same problems that we have seen in some 02's and there will certainly be some new problems. Each change brings about its own set of potential problems. Look for obvious problems whatever you buy, and try to buy from a dealer that will work with you if problems do occur. Bottom line is I don't think waiting for an '03 is any guarantee that you will have fewer problems, and an 03 is guaranteed to cost you more. The problem, at this late date would be finding an '02 equipped the way you want it.
I have a build date of 6/01, part of the "early" batch that seems more prone to leaking etc... btw, Chevy did make a few changes mid year, like different (slightly wider I think) cargo panels.

The good news is that I have absolutely no problems with mine (yet)! Haven't had ANY rain here in AZ since I got my Av, but took it to the pressure spray do-it-yourself car wash and couldn't make it leak, short of high pressure blast directly at the seals (unlikely to happen in real world conditions.) and even then it was just a few drops.
No problems here. I love the truck. I dont know if this helps to prevent leaking but, once a month i spray silicone greece in a small foam paint brush and paint all the weather striping on the truck to keep it moist. I have had no leaking problems.
Just want to pass some info on that I received from a friend of a friend, who has a brother that knows a guy who details the car of a GM customer/Factory laison in the Pac. N.W. area.

Apparently, says the Liason: The long soak/smoke issue, is most prominent in Canadian (Tonawanda) build 5.3L engines. And is not restricted only to the Avalanche. They (smokers) are using Eaton supplied lifters which have a larger capacity and are somewhat more prone to leakdown than the Delphi lifters used in U.S. assy's.
This and the low galley intake, PCV/vent locaton, pools more oil on leakdown causing this Start-up smoke. PCV replacement helps allieviate this isue as does siliconing the vent baffles by restricting the orifice size and return system, but peice to piece variations in lifters and Engines, may continue to show smoke untill the lifters are replaced.

Anyway thats my $00.02. and the threads here, and at FullSizeforums tend to bear this out. So I'm stickin to my answer Pat. That's Whoopie Goldberg in the center square for the win!
Mine is an 07/01 build date, and the only problem I've had is an intermittent smoking on start. That's not happened again since the dealer replaced the PCV valve. My interior has remained bone dry since the day I got it. Although I did notice that both my rear bed covers and the rear window are of the "new" type. I wonder if mine was one of the lucky Avalanches chosen for Chevy's quality inspectors to review before shipping? At least I didn't have to deal with it.

Anyway, with the incentives and dealer's need to get rid of the '02s, getting an '02 sounds like a plan, provided you can find what you want.
TDHeller said:
Anyway thats my $00.02. and the threads here, and at FullSizeforums tend to bear this out. So I'm stickin to my answer Pat. That's Whoopie Goldberg in the center square for the win!
Yep... very good post. Replacing the lifters resolved the smoking/oil consumption issue for jst4f many months ago. The "patches" (different PCV valve and RTV sealant beneath valve cover) resolved the problem for me.