M30 oil canister


The problematic valve is actually the one that isn't circled...
Procedure and photos courtesy of Tom O.

A major problem with the Bmw E34/E32 M30 3.5l: slow oil pressure build up.

• Oil pressure light abruptly began taking nine to ten seconds to go off upon cold starting.
• Dreaded"chime" for low oil pressure. When restarting after short runs the light goes out very quickly.

Diagnostic of the Canister problem from Adnan:
1. Removed pressure sensor and used a gauge to test actual pressure - normal.
2. Replaced sender with new one, no effect.
3. Changed oil filter and paid extra attention to o-ring on center bolt - no effect.
4. Let car sit a couple of days and opened canister bolt and took off cap. Canister was completely empty.
5. Cranked engine using diagnostic connector and watched oil come up immediately into canister through check valve, indicating that oil pump was primed and operational. Placed Saran Wrap over canister first.
6. Installed center bolt (without cap) and poured some oil into outer chamber. Oil drained back down the check valve (located on the floor of the canister near the lowest point).

Conclusion: the plastic-bodied check valve had failed and was allowing the canister to drain back. Consequently, when the engine was started after an overnight sit, the canister had to fill first before any pressure registered at the sender.

Solution: Purchased a new canister housing from Pacific BMW for $270. It is interesting to note that BMW has completely redesigned the check valve and over-pressure valve to eliminate plastic. This suggests that there may have been a fair number of failures in the field.
Installed new housing (requires removal of alternator and a small wiring harness; took a couple of hours including cleaning all the grime from parts). Poured oil in both center and annular chambers of canister, added filter, buttoned it all up.
Oil light now goes out in two or three seconds, like it used to. Engine has quick oil pressure and the pressure's off me. I hope this will be of use to others.

Ok, Call me cheap, but I don't feel like spending this much money on German's engineers mistakes.

Trying to solve the problem the "cheap" way from Tom O:

This is what the innards of the oil filter housing look like.

The seating surface of the black plastic has some rough spots. The cross-shaped steel plate got a bit chewed up during extraction.
Possibilities I see are:
1. Dressing the plastic with a lathe.
2. Substituting a steel ball bearing of the correct diameter, with or without the spring (which would now be a bit too long).
3. Begging the part out of Bavaria, I'm assuming the housing's seat would be OK?
4. Installing a new housing.

My machinist (Butch) wasn't at all optimistic about my idea of the ball bearing--he mentioned the seat might not be right(?) Don Gale agreed the spring would be too long and might not allow the valve to open far enough. The machinist thought either the lathe might work, or else seating it by spinning it in place with abrasives (like head valves--I forget the terms). Either way, he isn't overly optimistic, and suspects it would fail again (although the original apparently lasted quite a while).

The MB star causing the problem

The plastic seems relatively hard. Using a 10power hand lens I can see that the beveled plastic surface shows wear on opposite sides. On one side there is a small groove, and the other side has what is like a partial new surface worn at a slight angle to the original bevel. It looks like the plug was meeting the housing's seat at a slight angle off of perpendicular. After all, there is no valve guide--just the spring on one end and the MB star on the other. I guess that the MB star does a poor job of keeping the black plastic valve at the correct perpendicular angle. Oh oh, looking again, I see the fins of the MB star appear worn, too.

As far as milling a new poppet out of nylon (Bob Inyelm's suggestion). I think the difficult part would be excavation of the MB star which I surmise is needed to allow oil to pass while keeping the plastic poppet centered. Also, it seems that regrinding the poppet against the housing's seat would be nearly impossible without further damaging the fins of the MB star.

After writing this and looking closely at the part, I'm getting very pessimistic about its repair. Hendrick and Murray BMW Denver both said flatly that the part is only available as the entire housing.

Now what? Do I spend the $270?:
If you want the OEM look for your engine, no other choice, break the piggy bank.

If you have a MAF, an electrical fan and a supercharger, you don't really mind changing the aspect of your engine compartment, so this is the idea:
There is a kit called "oil filter relocation kit", some companies sell one for the E34, but it cost more than the canister itself.

We developped a remote canister plate, the pice is 99US for the plate and 149US for the complete kit. The addition of an oil cooler and oil gauge is easy in the future.

Complete kit: 149US+ shipping
- 1 engine adapter
- 1 remote oil filter mount
- 4 hose fittings
- 6ft of special INSTA-GRIP hose (no hose clamps needed)
- 1 BMW gasket
- 1 manual and sticker

Engine adapter only: 99US + shipping
- 1 engine adapter
- 2 hose fittings
- 1 BMW gasket
- 1 manual and sticker

Blue anodizing extra (other colors will be available soon) - color hoses (blue, green, red, yellow) extra. Stainless steel braided hoses with crimped fittings extra.

Miine has been working for more than 1 year on my 535i on the track, email me if you want one for your car.


Thanks to Tom O. and the E32 gang: Bob, George, Don, Alex
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