2002 Impala

Anonymous-0 · Aug 19, 2012

My son has a 2002 Impala with the 3.4 motor. There is a water leak behind the motor towards the left back corner. What is there that will leak? Need to look at it later today. Thanks...

tedregentin · Aug 19, 2012

That wonderful engine is known for leaking intake gaskets, among other issues.

Royse · Aug 19, 2012

I've seen lot of 3.4's with leaking intake manifold gaskets, but I don't recall them leaking much externally, just a little on top.
It would definitely be worth checking the oil for antifreeze though. Common problem.

El Toro · Aug 19, 2012

You may have a freeze plug leaking. Had that problem on a 1980 Buick with the V6 engine. Had to have the transmission pulled to replace it. Hal
PS: You may have lost the rust inhibitor in your antifreeze.

PeteTheRookie · Aug 19, 2012

UGH.
We have a 2002 Pontiac with the 3.4 transverse mounted (FWD) V6. What a total POS.

Most likely the rear head gasket.
Did this engine over heat?

This design originally had a cast iron block with cast iron heads. When they switched over to aluminum heads the design failed in my opinion.

I just got thru pulling everything off the top of the motor to change the intake manifold gasket. I t had already been changed once already at about 75K, it now has 115k.
The intake gasket was weak, changed it as I was hoping that was the issue again. BUT the real problem is the rear head gasket on nbr 1 cylinder is leaking. When we pulled plugs we found water in that cylinder.
The way the water jackets pass from head thru intake manifold it will leak water(hot and under pressure) into the oil if that part is bad. Or, seep oil into water. We had oil in water and only detected water in the oil with a oil analysis. There was no visible signs of water in the oil.

I will never buy another GM V6 in my lifetime.
Pete

1206SWMO · Aug 19, 2012

The 3400 series GM engines are notorious for leaking intake manifold gaskets...Over the years a great many of these engines have been ruined when it leaked inside....How GM ever got away without a recall is beyond me..

We once owned a 2002 Buick Rendzevous CXL for a year..What a piece of junk..It had the 3400..

1206SWMO · Aug 19, 2012

I just went back and checked some of my old posts at Edmunds about the 3100 and 3400 GM V-6 engines...I can remember when there were websites devoted solely to these engines telling what lemons they were..

The 1995-2003 GM 3100 and 3400 V-6 engines were plagued with blown intake and head gaskets..If you pushed GM really hard they would sometimes pay for them..Most of the time they would simply deny that there was a problem..They sure lied to me..

The 3.8 and 3800 series GM V-6 engines are great...I've put lots of miles on them with no problems..

2002 Impala

Anonymous-0

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tedregentin

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Royse

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El Toro

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PeteTheRookie

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1206SWMO

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1206SWMO

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