ware the throttle body is ware the EGR gas comes in to the plenum,a small hole on one side two water passages go down the sides. was running fine stoped at store come back out started the car and it run very erratically and stop. the water had just about fulled up the plenum and the water got in to two of the cylinders and lock it down would not trun over. took the plugs out truned it over 3 or 4 times to get the water out of the cylinders. put a new plenum and gaskets on would start run as long as it was about 1500RPM wouldnt idle but now it just dont want to run at all disablyneed help Thanks
Upper intake plenum water leak inside the plenum just inside on 1995 Buick Park Avenue
wgat motor do you have?
3800 (L36) has the black plastic plenum not a good design
1 more answer , 3 more comments
sounds like you have a blown head gasket
checked all the cylinders for compression all at 150 / 155 psi
Did you remove the PCV valve, o-ring and spring from the old plenum and install in the new?