Im working on my friends car. His complaint was car was losing coolant, and nothing showing up on the ground. Did leak down test and sytem loses pressure. Used a Napa block tester and tested positive for exhaust fumes in the radiator. Also a little oil is showing in the water.

So this looks like a tell tale sign of a head gasket/ head problem. But i read about these pesky cylinder sleeve o-rings.

My question is how to i test just these o rings once I get the heads off? just bolt a flat piece of steel with gasket material to the block and pressurize? Is there any other tricks? Or will i have to bolt the heads on with the new gaskets and do a leak down type test again?

thanks for reading,

appreciate all input,

rob

you check the compression, if something was weird that would at least narrow it down

I never did much heavy duty work on the 4.9 in my time at the Cadillac dealer but if memory serves me correctly the 4.9 was way more sound and the sleeves seemed to stay in the block when you removed the head. I know the 4.1 and 4.5 were a complete nightmare when you removed the heads. It was kind of a 50/50 shot they weren't going to leak after you bolted the engine back together.

according to a couple threads i saw on the net the sleeve on that is press fit at the top and the oring is at the bottom to keep the coolant out of the oil. so if there is exhaust in the coolant it would have to be head gasket right? if it were the orings there would be oil in the coolant and coolant in the oil