Mechanics

CHEVY COOLANT LEAK

2001 Chevrolet Impala

Engine Cooling problem
2001 Chevy Impala 6 cyl Two Wheel Drive Automatic 136, 00 miles

It appears that I have a coolant leak behind and possibly slightly below the thermostat housing. I can hear the sizzle on the hot engine when the car is running, but can't locate the source due to everything in the way. My question is, what would be the probable source(s) of ca oolant leak in this area? Also, is there a good way to get to this area to work? Any input is much appreciated.

Thanks,
Hank
Avatar
HankO3rd
November 12, 2008.



Hi Hank: Most likely the coolant is leaking from the t-stat housing and making its way back. It could be something as easy as the hose itself. Give those a check. Also, take a flashlight and check around the intake gasket areas. You may have an intake gasket leaking. Look for coolant or evidence of a coolant leak.

Let me know what you find.

Joe

Thanks Joe, I recently replaced the thermostat thinking that was the casue of overheating. I was careful to ensure that there was no leaking when I did it. I can see behind the thermostat housing black residue and coolant pooled below that on the engine and frame. There is white smoke coming from the exhaust, it is light and earlier I attributed it to cool weather, but today is mild and I still see it.

Tiny
HankO3rd
Nov 12, 2008.
Hank: White exhaust usually indicates an intake leak or head gasket. Somehow coolant is getting into the combustion chamber. Check the oil for coolant contamination and the coolant for oil. If there is no evidence of contamination, you will need to have a compression test done. Also, based on where you described the coolant to be, it sounds like an intake problem. Does the car have a 3.1L V6? It's a common problem with them.

Let me know what you find or if you have other questions.

Joe

Joe,

My Impala is the 3.4L v6. Here is the scenario from today. Started the car to move it around back to work on. Large ammount of white smoke from teh exhaust which subsided to a small steady flow. The car runs fine, without teh thermostat showing it overheating. When the low coolant light comes on I shut it off. I can see steam coming from the engine under and behind the thermostat, I can see where the coolant is running toward the rear of teh engine comaprtment and pooling onto the ground. I still cannot pinpoint source of the leak. There is a block Oily buildup on the side of the engiune in this area. I am geting some engine cleaner so see if that helps me locate the source. The Oil seems fine and I dont see a " mikshake" residue. I am pretty certain that it is origionating from the area behind the t-housing.

Thanks,
Hank

Tiny
HankO3rd
Nov 15, 2008.
Hank: Let me know what you find after you clean off the engine. I hate to say it but my gut feeling is the intake gasket. If you have a lot of white smoke, that usally indicates coolant geting burned in the combustion chamber.

Let me know what you find.

Joe

Joe,

I found the leak I think it'e the upper intake manifold (following the seam, it runs below the t-housing) the leak appears to be at the point the seam angles upwards towards the rear spark plug housing. There still isn't waht I'd call alot of whie smoke. But its present and the pooling under the car from the leak is obviouse. If I am follwoing you this is the upper intake gasket.

I have a Haynes Manual, is there a better guide to preforming this repair? My car differs in the upper intake manifold has six fasternes (there is one or two for brackets I think), not the 12 shown. I'm guessing this is a variation in model years.

Thanks,
Hank

Tiny
HankO3rd
Nov 16, 2008.
Based on your description. it sounds like the intake. Not being there limits me. Regardless. if it's leaking, it needs repaired.

As far as your manual, yes they provide variations for different years. Mitchell and Chilton are other manuals you could check out. They are both a quality resource. I was able to up load a picture of the upper intake. Let me know if this is what you see.
[
img]http://www.2carpros.com/forum/automotive_pictures/249084_Upper_Intake__34_GM_2.jpg[/img]

Joe

Joe,

That looks like it. It seems like the hard part is remembering where everything goes that you have to disconnect to get to it. I guess that is what digital cameras are for.

Any tips besides patience before I tackle this one?

Thanks for all your help with this, I truly appreciate it.

Hank

Tiny
HankO3rd
Nov 17, 2008.
Patiences is about all I can tell you. Good luck and if you run into trouble, let me know and we'll figure it out.

Joe
PS: Let me know how it goes, and use some masking tape and a sharpie to mark items to help remember locationa.

Joe,

I truly appreciate you help with this. I'm going to give it a go Saturday morning. I'll keep you updated.

Thanks,
Hank

Tiny
HankO3rd
Nov 18, 2008.
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