Persistant PCV Oil Issues

[MIPS]

When I got my Eagle it had a major issue with oil being blown back into the air cleaner and making a mess of the filters and the carb.



I've already checked the cylinder compression and even with a poorly fitting tool found that each cylinder was between 135 and 140PSI, so there shouldn't be serious blow-by. I was finding that I would sometimes have an acceptable vacuum present at the valve cover breather port but other times it was not there. I replaced the valve cover gasket, replaced the valve cover grommets and replaced the PCV, related hoses and PCV breather filter element.



I am still however finding that only after a week the filter is turning yellow and oily from oil being blown back into the cleaner. Sometimes I'll inspect it and find the positive pressure in the crankcase has forced the element out of the orange housing. Where on earth is all this supposed blow-by coming from? I'm not getting smoke out the filler cap when revved or crazy amounts of burning oil.

[AMC of Houston]

Not sure what year your Eagle is; but do you still have the PCV Solenoid plumbed into the system??  It shuts off PCV vacuum at times.   It should have disappeared years ago due to an AMC Recall, and been replaced by a special hose with an orifice within.

[MIPS]

Sorry, 82 model year.

My Eagle does not have the solenoid but it also doesn't have an orifice-fitted hose.
This is what it came with. White plastic elbow and rubber hose to the cleaner. Nothing else came out when I squeegeed the oil out of it so it's just an unrestricted connection.

[AMC of Houston]

That hose should be an unrestricted hose, as its the PCV system "intake".  No problem there. 

The solenoid and/or recall hose would be plumbed in from the PCV valve to the base of the carb.  The original solenoid electrical connector is probably still laying somewhere around the carb/intake.

[MIPS]

When I replaced the PCV vacuum line I found no traces of the solenoid or anything else attached to or inside the old hose.

[Eagleearl]

Interesting. Do you have good vacuum at the PCV valve?

[MIPS]

It has a strong vacuum at the PCV at idle.

I actually did a 400km trip starting Friday and noted that the hard load of two mountain passes blew a ton of oil back into the air cleaner and ruined the filter. I wiped down the cleaner housing and replaced the breather filter and the next 250km downhill and on flat highway has been great with pretty much no oil in the cleaner.

[MIPS]

Yeah, spoke too soon.

For anyone who takes the Coq (Yellowhead Highway 5) from Kamloops to Hope you have five long hills and two passes at 4700 and 4100 feet.
I changed the PCV breather filter again (and also adjusted the filter angle so oil was more likely to not collect at the bottom of the breather filter housing) before leaving town (and kept at or below half throttle to see if it was a lack of manifold vacuum at open throttle) and checked the air cleaner after the first two hills and things were still good, so at the highest travelled altitude (and the lowest possible manifold vacuum) things were okay.
I checked again at the coq summit and again somewhere between Merritt and there it had again coughed up oil and made a mess of the cleaner AND was blowing oil out around the rubber fill plug on the valve cover. Didn't lose much oil but it still made a total mess.
Other than that, it still has no oil issues with regular city and flat highway driving both at sea level and up here at 1500 feet. It's just not liking these long and hard pulls.
I took the car in to have an actual shop verify I wasn't seeing some vacuum leak or blow-by issue that I have not been able to diagnose and he came up with nothing other than "It's not blow-by, it's normal, especially for an engine barely over 250000km." Also recommended I buy another filler plug as mine was a loose fit but sent me on my way without wanting money for the test. He appreciated that I was still driving an Eagle.

Does anyone have more details on the PCV solenoid replacement kit, notably the orifice fitting?

[amcfool1]

hi, afaik, that pcv solenoid was troublesome, and actually recalled by AMC due to constant clogging. You may just have a tired engine. good luck, gz

[MIPS]

Problem solved.
My aftermarket valve cover uses an all-rubber plug for the filler cap. It fit well enough but I guess with age it slightly shrunk and was a vacuum leak even though it didn't rattle in the hole. Swapped it out with a new one (Gates P/N 31272) and I got crankcase vacuum back consistently. I just ran the car for a week on the same circuit over the mountains as before and did not find oil blown into the air cleaner housing.

[johnbendik]

I'm jumping into this thread because I recently started having the same problem.  I used to have a Fram 'breather cap' in the oil filler hole of my valve cover, and it always deposited oil on top of my valve cover.  To stop that, I replaced the breather with a standard rubber plug, and replaced the other gaskets on top of the valve cover.

So now I have a pristine valve cover and an air cleaner full of oil.  I'm afraid this means that my rings are shot... but I looked and I do indeed have the problematic PCV solenoid that y'all are talking about.

I looked on EPedia for the related service bulletin but can't find it.  Is the fix just to remove the solenoid and splice the two ends of the hose together with some kind of jiggery (or just replace it)?

Thanks in advance,
JB

[AMC of Houston]

It was a "recall kit" consisting of a new hose with an orifice built in to reduce the flow a bit to keep the carb from leaning out too far at low RPM.  I have one for a std-tranny car in a box somewhere (was different part number than the auto's).   I'd just try a bypass hose without any orifice and see how it acts.

[MIPS]

As above I'm running without an orifice and identical to the below diagram. I am running lean but that's more a carb tuning issue from a rebuild that I have not addressed yet.



The only issue I've had so far was finding the T- reducer fitting that is on top of the PCV valve as Fram and the likes only have the PCV valve with an "F" style reducer fitting. I ended up buying a Fram FV391, popping the T-fitting off the old PCV valve and popping it on top of the new one.