Intake Plenum Leaking 03 GT

Carwhiz · #1 04-05-2006, 07:49 PM

Hey everyone, I'm pretty bummed out, I was changing my oil today on my 03 GT 3.8 with 46000 miles and I saw the coolant was just under the cold mark on the overflow tank. So, I know the plenum is a common problem by the EGR valve, but this young??!! Sure enough, right behind the EGR there was a coolant run comming out of the plenum, and a small puddle sitting on the intake. I just bought the car 6 months ago with 28000 miles on it, yeah, my wife does a lot of driving. Anyways, I called the GM dealership where i bought the car at and they said about $400 for a entire new plenum/gaskets/labor. I can buy a new plenum for $150, but this new of a car I am nervous to work on. Any sugestions would be helpful on whether or not I sould tackle this job!! The only issue I am concerned with is the injectors/fuel rail. I'm normally would jump right on this job, but this new of a car kinda shakes me. Please drop any suggestions/comment!!!!

JRTBandit · #2 04-05-2006, 10:31 PM

There is a lot of info on this topic just do a search, this is a fairly easy job if you are handy. A important thing is to replace things in reverse to the way you removed them and when you start up the car and see white smoke don't panic (I did). If you run into trouble there is a lot of good help on this sight (not me) and Richtazz may be able to get you a better price than that on the part if your intrested. Good Luck!

Here is just one posting-

http://www.automotiveforums.com/vbul...t=upper+intake

BNaylor · #3 04-06-2006, 08:05 AM

Unless you've done this type of work before and have the knowledge, experience and resources to DIY go for the $400 repair at the dealership. That is a very reasonable cost.

BTW - Here is a link to show you the opposite viewpoint when the job goes wrong:

http://www.automotiveforums.com/vbul...d.php?t=541395

richtazz · #4 04-06-2006, 08:54 AM

I agree with Bob that $400 is very reasonable for this job. If you have the tools and know what you're doing, then it's fairly simple (takes about 2 hours or less). Since ham-fisted techniques can cause extreme headaches (broken bolts, vacuum leaks, cracking the new plenum, etc...), if you're not confident in your abilities, take it to the dealer and be done with it. If you decide to tackle it yourself, cleanliness, get a good in/lbs torque wrench, and no short cuts (replace PCV, injector o-rings, etc..) are the best advice I can give.

richtazz · #5 04-06-2006, 09:04 AM

two other things to check, as your mileage is way too low for this problem to be cropping up. Take a look at your odometer. If you shine a flashlight at it, can you see silver lines between the numbers? If you can, it's a sure sign of odometer tampering. You may also want to run a CAr-Fax report on it to verify mileage. There is a lot of deception in the used car biz, and the dealer may know that they did something wrong and are trying to cover it up with the good deal on the work it needs.

wlkjr · #6 04-06-2006, 09:08 AM

Does this repair usually cost more than $400?

BNaylor · #7 04-06-2006, 09:11 AM

The UIM coolant leak sounds premature considering the '03 shouldn't be having this type of problem. After all it does have the improved UIM and gaskets, etc. I think the dealer is just splitting the baby. Typical dealer cost with all parts and labor normally runs around $600 - $800.

If he picked up the phone and called Pontiac Customer Service complaining he might eventually have GM agree to help defray some of the costs anyways which is around 50%. It seems to be standard practice nowadays if you scream hard enough.

wlkjr · #8 04-06-2006, 10:20 AM

Do all the early models have to have new gaskets or is it just some of them. I've never had to have mine done but my oil analysis does see a potential problem with antifreeze in the oil. Potassium level at last analysis at 300,000 miles was 14 and a previous level of 29 at 265,000 miles. Comment on analysis was " if potassium is coming from cooling system, it isn't getting any worse and isn't hurting anything." I think I am going to ride this one out as far as I can.

BNaylor · #9 04-06-2006, 11:21 AM

Quote:

Originally Posted by wlkjr

Do all the early models have to have new gaskets or is it just some of them. I've never had to have mine done but my oil analysis does see a potential problem with antifreeze in the oil. Potassium level at last analysis at 300,000 miles was 14 and a previous level of 29 at 265,000 miles. Comment on analysis was " if potassium is coming from cooling system, it isn't getting any worse and isn't hurting anything." I think I am going to ride this one out as far as I can.

The initial TSB out on the problem covered 1997 - 1998 with Vin "K" first.

I'd leave well enough alone. You are doing great with that mileage.

Carwhiz · #10 04-20-2006, 10:35 PM

Howdy Folks, well I fixed my leaking intake myself and there was nothing to it. It took exactly hour and a half putting on a new upper intake with gasket. General Motors said this problem is still common on the new 3.8L, and they were willing to go 50/50 on parts/labor. I still fixed it for less than that. I paid $110 for a dorman upper intake kit which included EVERYTHING I needed to get the job done, new o-rings, gasket, plenum, vacuum lines, and even a new pcv valve.

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