Oil leak - 1997 850 NA

DennisCA · Post by **DennisCA** » 01 Feb 2025, 05:29

Right, so a while ago I discovered I seem to have an oil leak

It seems to be concentrated on the passenger side. I was wondering if it was leaking behind the cam seals, but looking at the timing belt it looks fine to me. I replaced this just a few months ago along with a new water pump and rollers.

Removing the intake showed me this, oil leak looks like it's coming from behind the PCV trap

I also found mayo in the hose that goes from the PCV trap to the intake.

More mayo, this is turning into a real sandwich

Trap removed

Rear of the trap

I noticed that the lower connection of the trap to the crankcase was quite loose so I can see it leaking from there. It also seems to be leaking water mixed oil back into the engine, that doesn't sound good? Is there supposed to be that much water coming from the valve cover?

And would it leak much oil if the connections between the oil trap and crank case were bad?

I'm not really sure what has caused this, if it's just a bad PCV system or a sign of something deeper?

DennisCA · Post by **DennisCA** » 01 Feb 2025, 05:38

I want to add I see no evidence of the mayo around the oil filler cap or the top of the PCV hose, it's only down in the trap.

454cid · Post by **454cid** » 01 Feb 2025, 16:32

Lots of short trips maybe?

Post by **erikv11** » 01 Feb 2025, 22:28

Short trips in cold weather = mayo.

Leaky hoses on the oil trap = mass underneath.

Definitely clean out the passages into the block while you have it apart.

DennisCA · Post by **DennisCA** » 02 Feb 2025, 00:14

I used the car for commuting and that's a 30km one way trip so I don't think I get a lot of short trips. But I am hearing from others it's hard to get around. Last trip I took with this was maybe 6km though.

A lot of oil has leaked out so I am wondering if the oil trap alone can explain for it all. Someone pointed out it looks like it also could be coming from the crankcase front seal, or possibly the filter.

DennisCA · Post by **DennisCA** » 02 Feb 2025, 03:45

erikv11 wrote: ↑01 Feb 2025, 22:28 Definitely clean out the passages into the block while you have it apart.

By the way can this be done without removing the oil pan?

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Today I also had the filter off and checked it, it's a Bosch filter, made in Germany and it looks fine. I don't think it's responsible, all signs now point towards front crankshaft seal. So I'll be removing the timing belt and while I am it I want to clean the side of the engine and the front of the engine while I have it disassembled.

What's a good engine cleaner for this. Brake cleaner + brush and rag doesn't do much here, just makes things dry, but dirty looking. I think something I can apply and then rinse off with water is probably best. Plugging up all the ports of course and covering the alternator first.

DennisCA · Post by **DennisCA** » 02 Feb 2025, 10:50

Ordered a set with oil pump gasket, o-ring and seal. I'll replace those as well while I am at it.

Post by **Sveedy** » 02 Feb 2025, 12:41

You can clean it with dish detergent ( Dawn ) and a small brush. That will get most of it. Then I use throttle body cleaner for the tough or tight places.

DennisCA · Post by **DennisCA** » 02 Feb 2025, 21:51

Sorry I was thinking of the internal passages into the oil pan from the ports, you have to like use a stiff wire or similar to try and follow the 90 degree bends I believe. The ports themselves are sludge free however and were so when I bought the car so I don't think they are plugged.