well - ok-- I'll look into it-- will keep y'all posted--thanks

I had this exact symptom on a slant 6.
Oil turning black in 100 miles, oil in air filter.
Also burned a lot of oil.

Absolutely, positively worn oil control rings. Either that or they are plugged with junk. With 300,000 miles this isn't surprising.

However a compression test isn't going to tell you anything because the compression rings are different. You can have good compression and poor oil control, which is exactly what happened in my case.

If you change the PCV and the breather filter, this will only help temporarily. Blow-by will still be there.

In my case there was no smoke either, except on hard acceleration or deceleration- and I only knew that b/c someone was following me. Couldn't tell in my rear view mirror.

The only thing that will fix this is... new oil control rings!

It isn't so horrible. If you can jack the engine up, remove the oil pan, and pull the pistons out through the bottom, buy new rings at NAPA and put'em on there, you'll be good to go.

Not high expense if you do it yourself, but it WILL be a lot of labor.

The pistons will not come out through the crankcase!

Yes, it's possible to have plugged oil rings and poor oil control with good compression, but if the compression rings are working then combustion gasses don't get into the crankcase to create blow-by. Kreen from Kano Labs has been getting good results in cleaning out dirty engines for folks in the forum at http://www.bobistheoilguy.com/.

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Joshua

OK, yes, that is true, you need to remove the cylidner head also or the pistons won't come out. Sorry I left that detial out.

What I can tell you from my own experience is I had this exact situation on my car, and I had 145 psi compression on all 6 cylinders.

It's possible for the oil control rings to be worn out and not the compression rings, but it is more likely that if the engine is worn in general, both will be worn.

My point is that doing a compression test is going to tell you the condition of the compression rings. The condition of the oil control rings is not something you can tell from a compression test.

well, winter is over-- never did take the valve cover off - waiting for warmer weather to change the gasket. My last thought to this subject is could the problem be caused by a frozen pvc valve? either by sludge build up or water vapor in it?--it was below zero that week-- oh, no problem sense-twas only that once when it happened-- thanks, da Prof

I've never heard of a frozen PCV. Not saying it won't happen, just never had that happen. I will say that I had that same problem on my smallblock-powered wagon many years ago, and it was a couple of stuck oil control rings. I added some Sea Foam, changed the oil after a couple miles, repeat. Cured it for a while, but it came time for my son Josh to drive it didn't make the transition to teenage driver too well. At that point rings were the least of my problems!

Couldn't hurt to try to clean the crud out of the engine, could it? Use some of Dan's "soup" mix.

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If it was easy, everybody would be doing it.

I've seen a plugged up PCV passage in the intake manifold.

I don't think you need to flush the engine. I would use an HDEO instead and change it more frequently. BITOG seems to really like AutoRx for engine cleaning.

I had a problem with the original engine in my van. Lots of blow by! Oil in the air filter. This clogged the filter frequently. This caused it to run rich. The over rich condition caused the cat to plug! I replaced the cat, disconnected the crank case breather hose and ran a long hose like an old fashioned "road draft tube." My PCV was working fine. Eventually a rod bearing gave up a year or two later. You don't have to run a hose off the breather. I did it to keep the oil gunk away from the top of the motor.

Disconnect that hose going to the air cleaner!

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick