PCV tube blocked?

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PCV tube blocked?

Post by Matt01 » Sun Jun 16, 2019 8:03 pm

Hi All,

My car always leaks oil, Ive changed all the gaskets, but the oil seems to come from one place or another. I have an OEM PCV valve, but I was wondering if it ever happened to someone that the tube or passageway got blocked/restricted over the years.

Im just asking to see if its a common problem before ripping out the PCV system for inspection.


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Re: PCV tube blocked?

Post by Ed Lijewski » Mon Jun 17, 2019 5:35 pm

Lots years ago I installed a professionally rebuilt block in one of my XRs. Over time minor oil dripping occurred,noticeable when parked as always over a sheet of cardboard. During oil and filter changes I noticed wetness at the oil cooler seal and oil filter adapter to oil cooler seal. Synthetic blend oil dripped more than conventional as one would expect. Coupla years ago I ordered the correct gaskets and bolt o-ring for those pieces. Last Saturday I finally installed them. Made an immediate noticeable difference (time will tell if the change is sustained).

Another common source of oil dripping is a bad oil pressure switch. I had noticed mine was wet with oil film and installed new switch some time ago; no oil film or dripping from that area now.

Last edited by Ed Lijewski on Wed Jun 19, 2019 12:39 pm, edited 1 time in total.
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Re: PCV tube blocked?

Post by John Brennan » Tue Jun 18, 2019 8:24 am

Thoroughly clean the engine, then see where the oil drips from first.
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Re: PCV tube blocked?

Post by andyofcolumbusmerkur » Tue Jun 18, 2019 10:06 am

Some bolts go deep enough to get to an oil passage. Coat the threads with Indian Head Shellac. Hitting the rev limiter seems to push oil out of all kinds of places also.
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Re: PCV tube blocked?

Post by thesameguy » Fri Aug 09, 2019 10:34 am

I found the PCV hoses had hardened and didn't seal well, which reduced PCV effectiveness. Replacing the hoses did help.

My current battle is the VC breather, which sucks. I cannot get a good seal on the grommet in the head, and I don't know why. It's been that way for 15 years, first with the original '86 VC/breather combo and now with a Turbocoupe VC/breather. I personally blame the crap supply of aftermarket grommets. I am going to find a threaded solution, maybe weld a bung to the VC. It's a dumb, annoying problem to have on an otherwise totally dialed in engine bay!

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