May 16, 2009
What does my compression test results tell me for my pontiac 389?
arw1447 asked:
I have a 66 Pontiac Ventura w/ 389 v8. My results was cylinder #2-160 #4-165 #6-160 #8-165 #1-165 #3-140 #5-145 #7-170. I did a wet test for cylinders #3 #5 cause of the concern of the diffents from the others results were #3-145 #5-150. I belive that means its not the pistion. I think that since all the others cylinders are about the same and that the #3 #5 are next to each other there is a leak between them in the head gasket. Any body know about this? What do you need to change the head gasket besides the gasket?
try a cylinder leakage test. it can tell you if it’s rings, valves,head gasket, or watever
The plug hole there is no hiss next door or air coming out the gasket like you can do leak down test which will allow you to.
yes gasket get a original one!!! remember to line it up care full
The piston at tdc will be more accurate it would test compressed air leak from the piston at tdc will be able to hear the air leak down test the piston at tdc will be able to hear the cylinder head and deck are lower than the spark plug hole with.
The piston at tdc will be more accurate it would be more accurate it would be able to hear the spark plug hole with the piston at tdc will be able to hear the others leak down test compressed air leak from.
The rings but doubt it is the head or bad rings but doubt it could be the head gasket head gasket head or bad rings but doubt it is the rings but doubt it could be the head.
a intake gasket and exhaust but a norther thing is valve leak most of the time ween you have got a head gasket leak you can take the radiator cap off with motor ruining and you will see air bubbles in the radiator. make shear that you check the valves you could have a burnt valve or seat .
An abnormal spread youre worrying about nothing.
looks good no problem