Hi guys, I just found this board by accident and I'm glad I did. I have a Bonneville (SE) that I bought new in 1993. I've always liked the car and it has served me fairly well. It has a chronic coolant leak behind the throttle body. I took it to a mechanic that I trust and he replaced the intake gasket and that pretty much took care of it. Now, it is 1 year later and it is leaking again.

I've read where the series II engines have a prob with the intakes. Is this a problem with the series I engines also? Can someone recommend a good source for a replacement?

Thanks,
John


PS: I'm sorry if this subject has been beaten to death already

From what I hear it is mostly the series II which has the upper intake problem - upper intake degrades in the EGR pipe area, causing coolant leaks. Just to clarify, which gasket did the mechanic replace on your car, the upper intake or the lower intake?

It might also be the throttle body gasket this time. It'* a rubber seal between the throttle body and the upper intake. It would leak coolant in roughly the same area. It'* a whole lot easier to replace - with some tools and a good manual it shouldn't take you that long.

You can find a lot of good information by searching past threads... use the "search" link in the upper-right corner of the forums page. Some good keywords would be "intake" "failure" "coolant" "egr" "gasket", etc.

Sounds to me like the Throttle Body Base Gasket is leaking! Try replacing it with a new GM one.

Yep i'll second (third?) that on the throttlebody gasket. That happened to my '93.

Hey why is the throttlebody cooled anyway? It doesn't seem to me like it would ever get hot.

Thanks for the help guys, I'll tear into it this week.




I believe it is to warm it in cold weather for better gas mileage and reduced emissions on start up. Of course, this also warms your intake air under all other driving applications, thereby reducing power.

Yeah with that throttle body having coolant run through it, it turns into Mr. Ouch after a while of driving. Maybe one can put a solid gasket to keep it from flowing through? OMG I just resurrected a really old thread, haha.

You don't want to do that. The TB doesn't have coolant running through it to cool it. It has coolant running through it to heat it to prevent it from icing up.

yea I've had the TB gasket go bad on my 93 its a fairly easy process to change it

Lots of people mistake Throttle body leaks for intake gasket leaks.

a TB gasket leaking will drip coolant over the transmission