Hi folks. First off, my thanks to everyone on this forum in advance. I used to rely heavily upon this place a few years ago, but kind of fell out of touch. Second, I am very sorry this is so long- I wanted to be as complete as possible.

I still have my 1993 M50 525i (manual trans.) and it's currently at 107K. Here's what I am inquiring about. Please bear with me, as I also have a Q about how the PCV system may play a part...

It seems to "dump" oil (about half a quart) once every 500 miles or so. I say "dump" b/c the oil level ever so slowly lowers, but then all of a sudden it drops suddenly. I have been over and over this engine for five years- it has some seepage that seems historically unchanged where the head meets the block, and it also seeps from the oil filter canister lid- but very little and at high revs (I have tried and tried to stop this, short of using Permatex or paper thin gasket material.) In short, I don't think these things account for my loss, especially the sudden drop in oil level. It also does not appear to burn oil. I am, by the way, using Mobil fully synthetic. I also had to change my valve cover gasket about 2 years ago (at about 90K) as it was leaking oil into my spark plug holes. That seems remedied.

Now one thing I did notice, over the past 10 months or so, is that there seems to be some kind of blow by that appears to be oil coming from the little rubber tube that attaches to the manifold directly to the right of the throttle body- facing it from the throttle body side (driver's side) of the car. This little tube to the right of the TB shoots whatever right into the manifold, and again I see some kind of over spray that appears to be oil on the manifold where it connects. About 2 inches before where this tube terminates and in line w/ the total tube is a white plastic piece shaped like a childs spinning top.

Is this stuff part of the PCV system? My guess is that it is. Could this blow by oil be part of my oil loss issue? What might this blow by be indicative of (please don't say it's a terminal issue. I sure would appreciate any guidance.

I have also had an on-going gradual loss of coolant issue since I bought it. Can't find it anywhere- I have checked and re-checked all suspect areas, replaced the radiator/pump, etc. My mechanic has thrown up his hands also. The issues do not appear, I stress appear, to be related. No telltale mixing of coolant and oil, odd smoking, or anything like that. Our guess is that it's seeping some place we can't see it and burning off, leaving no drips or other tell tale signs.

Do any of you M50 owners have a similar problem? I'd love to hear from you.

Overall the car is still strong. I struggle with keeping it though as I fear it's going to become costly soon. At about 90K I had all kinds of things done- flushed out all fluids, plugs, all filters, guibo, clutch, radiator, water pump, aluminum water pump housing installed, EAT chip, M5 sways, and a suspension kit installed also. Overall a nice car, but again I am growing fearful of it.

Last Q, I promise. I get a knocking noise (metallic engine knocking) upon acceleration from about 2-3K rpms most obvious in lower gears. been doing it for a long time. Could the EAT chip be causing some kind of detonation problem? Again, it doesn't appear to burn oil, so although it sounds like piston slap I don't think it's a major issue. Any input here also appreciated.

My sincere thanks to all who read through this. I am at work, but will check back here later this afternoon. Have a good one!

Eric