ahahahahahaha

 

i am checking compression today. I was suggesting is that a good reading or what is? I read somewhere on here 150 was about normal also i have checkded for leaks and cant findanything. It only smokes bad at high rpms (when it down shifts or if i am having to use 1st for something) thanks for the info so far.

 

Ideally, it still shouldn't smoke, even at high RPMs. Double check the compression. If you're getting 150 psi for all 8 cyllinders, then I would say that your rings must be alright. If that's the case, you need to take a look down the throttle body and see if there is oil in the intake manifold. A little residue is normal, but in these trucks, even a little can be indication of blown plenum gasket. This would suck oil from your lifter valley, causing several problems such as oil burning, bad O2 sensors, bad catalytic converter, and the infamous "death flash" which is a computer reprogram that retards the engine's timing to hide the symptoms of the leak.

It still would be a good idea to look for leaks, because even with a bad plenum gasket, that is still A LOT of oil to be unaccounted for.

 

A compression test won't tell you the whole story. If the valves or guides are worn oil could be leaking into the cylinder and that would not show up on a compression test. A cylinder leakdown test is the only way to determine if your valves or piston rings are the problem. It is more involved and requires special equipment, but it will give you a better picture of the condition of your engine.

 

can i do that with some loaner tools from parts store or will it have to go to a shop

 

Some stores rent/loan leakdown testers, but unless you know how to use it properly the results may not be good. It's a bit more involved than a compression tester, but not really hard to do.

 

need to do a leakdown test for rings

 

If the plenum gasket is blown, does the oil get consumed during combustion? Mine is cunsuming a helluva lot of oil too but I don't see any smoke or oil leaks.

 

yes the oil is burned. modest leaks won't smoke.

common symptoms include oil loss, pinging/spark knock, clogged cat, higher cylinder temps, sluggish/lack of power.

 

I can't believe you're consuming that much oil and not smoking like crazy. It has to either be leaking or going somewhere else other than into the combustion chambers. Check your tranny fluid and make sure it isn't contaminated with engine oil due to a bad rear engine seal. See if the level is too high. And check the frame for any signs of leakage. That much oil could not be going out the tailpipe without some indication.