I just changed the PCV valve in my 00 OBW with 156,000 miles. This is the second time the PCV valve has been changed since it was new. The first change was probably 60,000 miles ago. I noticed quite a bit of thick gunk in the hose, which I cleaned out and put in a new Subaru PCV valve. My question is that fairly typical or could it mean other serious problems?

Also, I'm getting the head gaskets replaced next week. I have an external leak. I've never seen coolant in the oil or any gunk in the oil or on the oil cap. The gunk looked like thick brown grease. Is that fairly normal?

When I changed the PCV valve and the 'Christmas tree' (don't know whether others have it; it's a multi-way junction of crankcase ventilation lines) on my XT-6 at ~100,000 miles, I didn't have any remarkable issue with the PCV valve but the christmas tree was almost completely blocked off by hard carbon deposits. That engine had low compression on 1 cylinder and marginal on another before I fixed it.

 

If you have a brown sludge my thoughts would run toward whether there's a similar gunk inside the engine. Lots of short trips can allow condensation to build in the oil and result in a similar mess. So could a coolant leak...

Well I don't take many short trips. The head gasket leak is external, so therefore I don't think that coolant would be the cause of it. I also have never seen any coolant in the oil or any condensation on the oil cap. I change my oil every 3,000 with synthetic or synthetic blend oil. The old PCV valve was still functioning I believe as I could still hear the parts moving. Could this possibly be normal?

[...]This is the second time the PCV valve has been changed since it was new. The first change was probably 60,000 miles ago. I noticed quite a bit of thick gunk in the hose,[...]

[...]I also have never seen any coolant in the oil or any condensation on the oil cap. I change my oil every 3,000 with synthetic or synthetic blend oil. The old PCV valve was still functioning I believe as I could still hear the parts moving. Could this possibly be normal?

The PCV system has to deal with both engine blowby and moisture from condensation. It's not surprising that there's some buildup after 60,000 miles. Servicing the PCV is something you should expect to do; it may be needed slightly more frequently as the engine ages, but as long as nothing else seems to be wrong I wouldn't be concerned.

Well I guess I'll find out when I get the head gaskets done. No I haven't had any other noticeable gunk. No condensation on the oil cap or in the oil. I haven't had any other problems that I've noticed.

OK, well then you're probably fine. It's still not 'normal' per se, but may not indicate disaster.

It's normal for gunk to build up here.

 

Running good full-synth oil in my engine seems to have kept the build up to a minimum.

It's normal. You may want to change it a little more often if you are finding them especially gunked up. 60K is a long time for a pcv valve.

 

 

nipper

Also, I'm getting the head gaskets replaced next week. I have an external leak. I've never seen coolant in the oil or any gunk in the oil or on the oil cap. The gunk looked like thick brown grease. Is that fairly normal?

I think it is normal. Mine has always been this way, and it is fairly cheap to change once a year. Being dirty, is I think, how it was designed to get.

John