3800 non SC question


Pedal Masher !!!
My daughter's 95 Buick GS has a mystery I cannot solve, and I am about to take it to a radiator shop to see if they can. The car goes through about 1/2 gallon of antifreeze a month and has done so for about the last 6 months. No Antifreeze in the oil (I know, I thought the same thing - blown Head Gasket), no Antifreeze under the car, and no sign of a leak that may be slow enough to be vaporized by the engine heat. I am stumped !!

Anyone with a history on these motors care to offer a suggestion on where I might start looking....

If it is a head gasket, how big a job is it to change one on these cars. ??

Car only has 66k miles and is otherwise a cream puff, in great condition, and has really no other problems..

Any help would be appreciated
I know you said that you havent seen any leaks but maybe a slow drip through the water pump bearings maybe?
On my 3800 there is a plastic elbow that goes from the water pump to the intake manifold water jacket. Its just an elbow with two orings on it and 'floats' captivated by the pump and the manifold. For what ever reason mine cracked at the oring groove so it wasnt a visible break and being on the low preassure side (I think) it never really leaked much. I would loose a half gallon every 3 months, I suspected the worst until I loosened the pump and inspected the elbow.
This sounds like the famous "non-visible", no-external- leak problem inside the "plastic" intake plenum. Find an EXPERIENCED Buick technician and ask if he has ever seen a similar problem with the "bread box". This is the first thing I would investigate.

That is what I am focusing on next (breadbox) ! Got several suggestions stating the same.


In trying to locate this part, I am getting mixed signals from my local Buick dealer. Does anyone have a way of verifying the part number I need for the Bread Basket on a 1995 3800 engine ??
I have been given part number 17113044. When I look this up in GM Direct, it says it is the intake manifold. That cannot be correct, can it ??
Also - how do I find the part number for the gasket that goes with this part....
There is a lower intake manifold which is aluminum and an upper intake manifold which is plastic. The plastic one can warp and cause leaks. There is an updated plastic upper intake that is not supposed to have this problem. If you get one, make sure it is the updated one.