jagevileye21

iTrader: (3)

What would cause an engine to smoke only at a high rpm?(Burning Oil) I am lending towards bad piston rings but I always thought bad rings would cause smoking consistently during start up and during driving.

Any input or suggestions would be helpful.

Thanks,
Jay

Rolling Thunder

Well its a complicated situation because even though it may seem like its only burning oil in the high RPMs this may not necessarily be the case. Reguardless however the point is to figure out where its coming from. 2 places that come to mind is past the valve guides and piston rings. If its valve guides and you hook a vacuum gauge up to it you will see the needle vibrate or some sort or abnormal behavior that's not related to the motor RPM. If its rings a compression test will tell.

jagevileye21

iTrader: (3)

I have an exhaust leak on the passenger side. When I popped the hood I see oil residue on the #4 and #6 exhaust port (LT1). I will do a vacuum test after work today.

Thanks for the information.

Jay

jagevileye21

iTrader: (3)

I did the vacuum test.

It was pretty low around 16Hg.

I thought it should be between 18-22Hg for a good condition engine.

There was no abnormal jumping of the needle although it did vibrate every once in awhile.

Thanks,
Jay

Rolling Thunder

16hg Depending on your motors mods is kinda low which is an indication of low compression (among other things). Ide now run that compression test see how that looks.