Help Locating/Stopping an Oil Leak

Post by **justanotherhumanoid** » 13 Mar 2022, 21:46

Hey all. I went to replace the lower transmission torque mount on my 2006 S60 2.5T AWD and noticed a few liquid drops of oil hanging out on the mount, as well as some evidence of leakage over time (pooling on the top of the splash guard, evidence of oil on the bottom of the oil pan).

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My first thought was rear cam seals, but the top of my transmission and the driver's side of the block look alright, so I don't think that's it. I don't think it's the rear main seal either based on where the oil is ending up.

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As far as I can tell, it's coming from the front of the block where a large hose goes to the breather box. About a year or two ago I replaced the PCV system completely and I remember this hose being a pain. I thought it was just vapors going through this hose, but I admit I don't know the pcv system that well. Is it possible that the source of my leak is this large diameter hose going from the front of the block to the breather box? Any other thoughts or things to check?

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Post by **cn90** » 13 Mar 2022, 23:01

- What brand is that PCV hose? Maybe MTC brand?

- Tighten that clamp a bit more, clean the oil leak and monitor it.

Post by **justanotherhumanoid** » 14 Mar 2022, 08:48

-I'm not sure of the brand, I ordered the whole PCV kit from IPD kit. The genuine volvo one:

https://www.ipdusa.com/products/4991/PC ... lvo-115031

-Rog... cleaning down there is going to be a pain but I'll get as much as I can and see how it goes. It does drive me crazy when there's oil on the block like that...but not enough to remove the intake and pcv stuff again.

Post by **vtl** » 14 Mar 2022, 10:47

PCV seems not working, oil is seeping through all the holes?

Post by **abscate** » 15 Mar 2022, 04:49

It’s probably a bad rubber part that has failed. OE Volvo only on those oil soaked parts

Great pictures!

Post by **vtl** » 15 Mar 2022, 06:38

That's too much oil for PCV trap. It might be leaking through the seam at the block halves. See the seam is right below the upper PCV trap intake (the engine is up side down):

There's a high pressure oil passage maybe 1/2" behind the front of the block. A leak there is pretty common. Unfortunately the cure is to take engine out, drain all the fluids, flip up side down, take the sump and lower section away, clean and reseal.

Post by **vtl** » 15 Mar 2022, 06:55

Oil passage:

Post by **erikv11** » 15 Mar 2022, 14:18

Very. very likely the PCV hose is the problem. Would be very unfortunate if that IPD kit has a cheap-o hose, maybe the problem is just the clamp as mentioned.

Post by **abscate** » 16 Mar 2022, 03:37

It’s certainly a lot easier to do the intake manifold PCVJOB than diving into the rocket surgery.

Nice pictures Vtl, it’s cool to see the insides of these things

Post by **songzunhuang** » 08 Aug 2022, 22:13

I have been chasing an oil leak for a long time like you. I changed the turbo seals, dipstick seal and I was still getting oil dripping down the front of the engine and blowing back all over the pan. The last culprit was the PCV system, but I was avoiding it since it's a time consuming job. Finally this weekend, I said - what the heck. This is on a 1998 V70 T5.

Off comes the fuel rail, throttle control and the intake manifold.

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Once I got the manifold off, I could clearly see lots of oil and dirt around the Oil separator trap box. I suspected one of the seals. The lower one to be exact.

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Sure enough, after I removed the trap box, it was plain to see that the Trap box coupler was useless. The rubber was broken, soft and swollen. It seems that too much oil exposure causes this on hoses, but it confused me that a coupler designed for oil would be affected by oil exposure.

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After a good cleaning (that took longer than the parts replacement) I put new parts for just about everything and buttoned it up.

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The next day I drove over 42 miles and there's not even a little bit of moisture in the area. I'd say we have found our culprit.