I have had a 96 D1 for a few years and love it and decided to pick up a used 99 DII recently. It has a lot of miles 160k but ran well. Reciently had the headgaskets done with studs and had a 3in lift installed. So after driving it a few weeks I noticed Black smoke from the tail pipe if you rev the motor. And along with it the oil level drops. Now I can drive around town easy all week and use no oil or take a 30 min trip on the freeway with a few full throttle passes and be way low on oil. At first I thought it might be sucking it in thru the pvc. So I cleaned out the pvc system(it was compleatly blocked)but no change. Any ideas?

 

Did you clean both sides of the PCV (both valve covers)?

Clean off the engine so you can see where oil is leaking. Valve covers themselves need to be snugged up (8mm 12 point 1/4 inch drive). Black smoke can be rich fuel mix, blue tint is usually oil, white is coolant burning off. Oil PSI rises when revved up, so might not be leaking on the milk run circuit. New gaskets would have used some oil, but that should have ended by now.

If can't find the leak, and you are running a good grade of oil, like Rotella 15W40, consider the White Shepherd oil treatment product.

 

First of why are you running it at full throttle?
Second the black smoke is normal for a full throttle run, that is the "A" typical sign of running to rich, which is normal because you are dumping in more fuel than it can use.
Third, at full throttle you are demanding the most from the engine and it is normal for it to use some oil, switching to a thicker oil will slow/stop this, the easiest thing to do it not to run it at full throttle.

 

I think I've hit full throttle one time since I've owned it, just to see what it had. Since then, I'm too nervous to blow something, so I "drive it like I pay for it".

My Jaguar XJR on the other hand... That saw WOT on a monthly basis. It was like a fighter jet on takeoff.

 

X2 on above, but consider that we also have members who make those steep long grade climbs in the mountains at 49 mph wide open, but they don't complain about oil consumption. More blow by the rings for sure, but if there is a leak, that is something that can get worked on for less money.

 

Yeah, if I were pulling a trailer up a hill, I'm sure I'd hit it occasionally.

 

I guess the question should be how low is "way low on oil"? Quart? Two quarts? Two ounce?

 

I go WOT on mine in sport mode from time to time, and I'm not crop dusting.

I'm going to guess either a PCV problem, or the valve seals weren't replaced during that head gasket job.

 

Over 160,000 miles I dont think I'd be going wide open throttle anymore. That little engine is tired, dang near worn out. Cut it some slack haha. These aren't Japanese engines. haha

 

I generally go up to 50% throttle, ever. I can't think of a time I've ever gone WOT. On my S60R however, that's a different story.