I recently noticed that my 76 244 B21F (Cal) has oil leaking down into the air filter housing from the flame trap hose.

Does this indicate worn rings? I did a compression test, but am not sure how to interpret it - it took about 4 or 5 compression cycles to build the correct pressure (170 psi). Went something like this: 110, 130, 150, 170 psi. This is all in about a second and a half or so of cranking. The instructions and my manual arent real clear whether this indicates worn rings or not. They say 170 psi should be reached "quickly", whereas a worn engine will build pressure gradually.

Anyone have experience with compression tests and or the oil leakage? Thanks for any help. Carl.

Rough idle in the K-Jets are usually caused by air leaks. Cracked or swollen hoses, bad gaskets, and worn injector seals all let unmetered air sneek by the air flow plate giving you a lean mixture that cause a rough idle. Other contributors to a rough idle would be the Control Pressure Regulator (cold or warm engine) the Auxiliary Air Valve (cold engine) or worn injectors (warm engine). Below is a diagram of the K-Jet System layout in your vehicle. If you check each system for leaks & function I'm sure you will be able to smooth out that rough idle. Good Luck!



Sincerely,
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Julio Meza

1979 264GL B27F 124K --> BW55->M46, CLS, IPD Sway, 81+ Dash, Gauges, Flat Hood

1979 262C B27F 160K --> Restore Project w/Possible B280F

1984 245DL 214K -->Wifemobile

Your final cranking pressure values are good - they indicate nothing seriously worn in rings or valves. 'Tight' engines will achieve 99% of their final pressures on the first two strokes - after that the needle barely twitches higher. I'd say you have a bit of ring wear, and thus maybe a bit of blowby. So, if your oil separator box/flame trap is not clean and fully functional, you are going to have positive crankcase pressures and some oil misting out into the filter box.

So (as mentioned) clean up the throttle body, ditto the separator box and flame trap, and make sure you have a clean air filter...it will start restricting airflow very quickly if it is being fed an oil mist. Excessive oily vapors fed into the intake usually wind up as deposits on the back of the intake valves which can yield rough idling and defy all cures short of major disassembly and cleaning. Maybe just live with it if the tune-up path doesn't work?
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Bob (son's 81-244GL B21F, dtr's 83-244DL B23F, 'my' 94-944 B230FD; plus grocery-getter Dodge minivan, hobbycar MGB, and numerous old motorcycles)

Volvodad, thanks much for this explanation. I'm getting a better idea of the problems my car has. This brickboard is a great resource because of you and the others who take the time to share their experiences. Thanks to all of you.

Sounds fine to me - usually takes a couple cranks to get to final compression. Important thing is that the final compression pressures across the cylinders is within 5%-10%. What was the final compression for 1,2,3,4?

Mark,

The final compression was:
1 - 170
2 - 170
3 - 180
4 - 180

The instructions say that exceeding the max can mean that carbon is built up in the cylinders. I'm wondering if this is not the case - plugs 3 and 4 sometimes have a light coating of oil on the gasket where they seal against the head. It doesn't seem to be dripping down from the valve cover, though.

This all came about because the car idles rough, and neither I nor several mechanics have been able to find the problem. I know rough idle can be about 20 different things, so I'm just taking it one at a time. Do you have any thoughts on the oil in the filter box? Thanks. Carl.

"plugs 3 and 4 sometimes have a light coating of oil on the gasket where they seal against the head. It doesn't seem to be dripping down from the valve cover, though. "
Check the back of the valve cover. If it's oily, the rear cam plug (half moon) make have hardened and is leaking.
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1980 245 Canadian B21A with SU carb and M46 trans

I would first start with a cleaning of the throttle body for the rough idle.

After that do a basic tune up with good ignition parts, don't skimp on these.

Pour a bottle of Chevron Techron into the gas tank prior to your next fill up, and fill up with high octane gas. It can do wonders.

Your compression test looks pretty good to me.

The oil in the air filter box is perfectly normal. I've got 3 240s ('76 245, '77 244, and a '80 245) and I've encountered this in all 3.

How much oil are you losing between changes? If it's less then a quart, I don't think you have too much to worry about.

Good luck!
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If you listen to the radio in Portland, OR, you may know me as 'Portland's Favorite Soul Brother!'

Thanks much for the advice on throttle body cleaning and other things.

Oil loss about 1 1/2 quarts between 2500 mile oil change.

Actually, I think this is pretty normal.

I usually see a little bit of oil in the bottom of the air filter box when I check the filter.

I wouldn't worry unless there is a lot of oil turning up.

Good luck!
--
If you listen to the radio in Portland, OR, you may know me as 'Portland's Favorite Soul Brother!'