BIG oil smoke at autocross today

[Jb325is]

I'm looking for some ideas as I start trying to diagnose my cars oil burning issue. Car is a '88 325is with an m30. Today I went to a BMWCCA autocross, the car ran fine, but on my first run after a long right hand turn I had a huge plume of oil smoke and the car kept smoking for the rest of the run. The smoke was the worst upon start up in the staging area but then cleared up at the beginning of each run until I got to the long right hander again. Oil level is fine, car didn't over-heat, no coolant/oil mix, and the car ran perfectly on the drive home, no smoke at all since. I did a compression test a few weeks ago and it was 160/160/160/160/157/160. Haven't done a leakdown yet but I will. A friend suggested oil sloshing onto the cylinder walls, and this would make sense because of the angle of the engine but why? Oil may have been half a quart over-filled but not enough to cause problems. Any ideas?

[jalopi]

How many seconds of cranking did it take to get those numbers

[Jb325is]

Not anymore than normal. 5-7 sec?

Hopefully I can do the leakdown test tomorrow so I'll have a little more info to work with.

[bmwman91]

Weird. I wouldn't expect extra oil sloshing onto the cylinder walls to lead to that much smoke unless the scraper ring(s) are shot. Your compression numbers look OK. You did the test with a warm engine and all 6 spark plugs removed?

[Jb325is]

Weird. I wouldn't expect extra oil sloshing onto the cylinder walls to lead to that much smoke unless the scraper ring(s) are shot. Your compression numbers look OK. You did the test with a warm engine and all 6 spark plugs removed?

Yep. This was on street tires also, I usually run on R-comps at least. So it definitely wasn't abnormally high cornering loads. I think it was the combination of high RPM's and long corner. I was at the top of 2nd at the entry

[jalopi]

5-7 seconds is kinda long. Were you just trying to squeeze out an extra 10psi or so? Did it hit 150 in about three seconds? Because I usually go by the rule of three seconds / three compression strokes.

[TobyB]

Was your oil level on the high side, perchance?

with the M10, there's a pretty narrow range where it doesn't leave the
pickup uncovered and it also doesn't get wrapped around the crank...

t

[Jb325is]

It was probably half a quart high. Oil level was perfect afterwards though, so that is a possibility.

It rose quickly and all cylinders were consistent. I guess I was cranking a little long though, I was waiting for it to stop rising. I get why you shouldn't do that though now.

[TobyB]

Duh- you said that at the top, and I missed it.

That would be my first guess, especially because its so easy to fix!

t

[Jb325is]

Yeah, the more research I've done I'm pretty convinced that was the issue. I was about 3/4 over filled according to the research that I've been doing. Still going to do a leak-down when I get back home just to be sure and I'll post results when I do.