2006 Pontiac Grand Prix - Coolant Leak

[kcota15]

My wife's car, a 2006 Pontiac Grand Prix with the 3800 series III engine, has developed a coolant leak. I tried to identify where the leak is coming from but can't seem to find the source. The coolant puddles under the drivers side near the front. I have done a bit of research and I know there are some common problem areas, one being the 90 degree plastic elbow near the alternator, but these areas don't seem to be the source. I do not see evidence of a head gasket problem (milky oil, milky buildup on the oil cap, etc.). The car has been running fine and I have been keeping an eye on the coolant level. Just wondering if anyone has any ideas of where/what I can look for to help pinpoint the issue.

[JOHNBIGDOG]

check the upper and lower intake gaskets, another common leak point.

look at all radiator hoses and the radiator itself.

[Jeremy airjer W]

The throttle body gasket in between the throttle body and the plenum is known to leak. Typically you will see the coolant crud on the lower firewall side of the throttle body. The gasket is serviceable but usually the plenum becomes weak in that area and is replaced at the same time. If it's a plastic plenum it's not a bad idea to replace it anyways since there are issue with them rupturing around the EGR tube and hydro locking the engine.

[kcota15]

I have found the leak. The radiator does have a leak. I was told that the gasket between the plastic and the metal of the radiator will develop leaks. Anyway, after pulling the fans and inspecting this area, sure enough there is a trail of coolant on the side of the radiator.

Anyway, I was looking to find the replacement online. The problem that I seem to be having is that my wife's car has the supercharger. Is this what is meant by "Special Performance Package." If it is no one seems to carry the part as the all say in the "fit notes" not for special performance package.

If this is the case does anyone know of an online place to order the radiator?

Thanks for the help. This is turning into a headache. I really like the car but it sure is a pain in the booty every time it has an issue.

[Macgyver55]

Just search Vista pro part number 434009 on the popular bidding site.

Or, to get one in the Twin Cities area ..call 1-800-radiator.

[kcota15]

Macgyver55,

Thanks for the intel.

[NIBOWMAN]

NAPA part No CU2862. There is one available in the Minneapolis warehouse.