My '93 850 has no sensor for crankcase pressure, therefore I have no way of knowing whether I'm running with too much pressure. I would like to somehow be more on top of this as I've spent $$$$$$$$$$$ on related repairs.

Has anyone retrofitted a guage or sensor?

Mark Sloo
Minneapolis, MN
'93 850 GLT, '65 122s, '65 122s

There is no better way. There is also no such guage or device as you're suggesting.
Any shop that does engine work (dealer, good indy) should have that tool and know how to do that.

A cylinder leak down test will determine if you have bad rings, the only other reason (besides clogged PCV system) why you'ld have high crankcase pressure termed "blowby".

Yes, I just had a major pcv system clog resolved, part of recall (service campaign) 69B. (see my many other posts on the brickboard) The oil separator/crankcase breather box was partially plugged and the vacuum line to the flame trap was completely clogged - possibly due to the failure of the crankcase vent hose.

I would just like to be on top of this and there are no sensors therefore no codes or check engine light (there are dozens of sensors resulting in codes for everything from EGR to the power seat!, but none for crankcase pressure), And, you can't physically check the system because you can't get at it without removing half the engine.

It takes 6 hours to do a thorough rehab of the pcv system on an 850. By contrast, it takes me about 10 minutes to do it on my 122's :-)


Mark Sloo
Minneapolis, MN
'93 850 GLT, '65 122s, '65 122s