oil in the airfilter

[Petros]

Hi all, I have been having an issue with way too much oil in the air cleaner again, I thought I would give you a quick history to see if any one has any ideas I may have missed:

1. About 2500 miles ago I had to replace the head gasket again, when I pulled off the air filter housing it was really full of oil (not normal). when I replaced the head gasket I also installed new valve stem seals, replaced the PVC valve with a new one, replaced the airfilter, and did a motor oil flush (Gunk brand, works like Seafoam in the oil), than new oil and filter.

After this my oil consumption went down, no more blue smoke on start up, and ran great.

2. My oil consumption had been creeping back up since the head a gasket change only 2 months ago, and the blue smoke on start up returned about 3 weeks ago. I had checked the oil level and the engine this last Saturday, added about 1/2 quart to bring it up to about 3/4 on the dip stick.

3. filled it up with fuel last night, no issues, but this morning after about 50 miles since the fill up, I had stopped at a contruction site to perform an inspection, and it was leaking motor oil all over. I lifted the hood and it was all coming out of the air filter in let. I had lost most of the oil I added on Sat, it was down to the fill line on the dip stick. I unplugged both of the pvc lines on the valve cover to keep it out of the air cleaner, this would have effectively disabled the new PVC valve and disconnected it from the induction system, but it still blew oil out on to the top of the engine (and all over the exhaust manifold).

Any ideas why I am blowing oil out the Pvc air inlet all over all of a sudden?

High crank case pressure (from worn rings) can cause it but it seems unreasonable that it would happen all of a sudden. Something I changed at the head gasket replacement fixed the problem, but now has reverted back to blowing oil again. It is possible that the new PVC valve is all gummed up again like the previous one? If so, how do I stop it?

[Mark]

I have a small oil catch can after my PCV valve to prevent the small amount of oil in the gases from being sucked into my intake manifold. It only collects maybe 2 cubic inches a month. You could try installing one on the other line before it goes into your air filter housing, but from what it sounds like, it would be full in minutes. You could disconnect the line from the filter housing altogether and route it to some kind of container that is open to atmosphere. I'm still surprised that, regardless of the amount of gases blowing by and the crankcase pressure, there's that much oil being carried along in the pcv system. When you disconnected the PCV lines did you notice pressure venting out of them? Or when you remove the air filter cover do you see/feel pressure venting through the pcv vent in the filter housing? I imagine nothing changed above the head that would be preventing oil from draining down from the camshaft area? I wonder if a failed valve stem seal on an exhaust valve would cause exhaust to travel up to the camshaft area. Who knows, maybe it's just a defective pcv valve, but that would probably be just too easy.

[Mark]

By the way, the hose from my PCV valve became disconnected from the intake manifold about 3 times without my knowing it. I think it was when I was moving around the filter housing for other jobs. I'm guessing this would cause a lack of vacuum at the pcv valve and I'm wondering if it would have enough internal resistance to prevent the gasses from venting through it and going through the nice open hose into the air filter housing instead.

[Petros]

the way the PVC system is supposed to operate is the line with the check valve comes from manifold vacuum, and it draws fresh air from the air filter housing, and than vents it through the crank case by it going down into the crankcase at the center/side of the head, and than comes up though the oil drain back holes on the front and back of the head, and than out though the check valve.

If the check valve plugs up, it will build pressure in the crank case and come out the inlet tube, which is likely what is happening. when I get home I am going to check the new check valve, perhaps clean it. On an engine with a lot of blow by it will go both through the check valve and the fresh air inlet into the top of the carb, but there should not be much oil in it, only vapor.

[irowiki]

Where's the check valve?

[Petros]

the check valve is the PVC valve, it is just a one way valve. it is the little device stuck in the grommet in the top of the valve cover, with a hose that goes to the base of the carb.

[4wdchico]

the check valve is the PVC valve, it is just a one way valve. it is the little device stuck in the grommet in the top of the valve cover, with a hose that goes to the base of the carb.

The PVC valve is not just a check valve. It is also a metering valve as it only allows a small amount of PCV gasses to be drawn into the intake manifold when the engine vac is high.

When engine vac is low the PVC valve will allow a larger volume of PCV gasses to pass into the intake manifold.

As far as your oil in the air cleaner issue goes: if your head gasket repair is not faulty and allowing compression gasses into the PCV system your lower end has experienced a failure, most probably failed compression rings.

[Petros]

I was wonder if this is the case, at idle I get a very large amount of vent gas coming out of the PVC inlet tube. of course at idle the PVC valve does not allow it to vent to the intake manifold as 4wdChico points out, but allows the crank case to vent only at open throttle conditions (low manifold vac conditions). It is still blowing oil out the pvc inlet port.

The engine runs good with no indication of low compression, I have no reason to think the head gasket has failed. It seems unlikely but it could be possible there is a cylinder or two with a broken ring that would allow a lot of blow by into the crank case. Odd thing is that it was it blew oil into the air filter before I replaced the head gasket. PVC valve and the valve stem seals, and was fine until yesterday, unrelated coincidence?

[dlb]

it is weird that you had oil in the air filter before the head gasket and other work, then it cleared up, and now it's worse, but youmay as well do a compression test to rule the rings out. only takes a few minutes. i can't think of what else would allow oil into the combustion chamber, then into the valve train area, and then into the air cleaner, unless there is another passage from the block through the head gasket and head into the valve train area. if there is such a passage i would check to make sure it is not obstructed, since that would caused increased oil pressure and could spray oil upward.

[rer233]

Itoo suspect bottom end failure (compression rings, pistons, or cyl. bores.) A cylinder leak-down test should let you know for sure. Only other possibility i can think of is plugged baffle in valve cover (unlikely.)

Good luck.

[marlinh]

Did you check for blowby by removing the oil filler cap with the engine running? At idle you will feel some pressure (for lack of a better term) but as you rev the engine it should disappear and actually create a small amount of suction.

[Petros]

when the engine was warm yesterday there was a lot pressure coming out from the PVC inlet (which vents directly to the crank case). I have not had time to do a compression test or a leak down, but I did rig up a catch can this morning with a hose that goes from what was supposed to be the PVC inlet into a plastic gallon jug so it would catch all the oil (1/4" vent hole in the cap to allow air out). When I started it to test it, there was no pressure coming out at all, no oil spray either.

The engine was cold because it was at first start up in the morning, I do not know yet if it changes as it warms up and I forgot to check it when I got to my office. But when the engine is cold at least on first start up, there was no gases or oil coming out of the PVC in let. BTW, I had to add almost 2 quarts of oil, that is how much I lost since Saturday driving less than 100 miles (one of the reason I hooked up the catch can). The engine compartment is a mess with motor oil all over, including on the underside of the hood.

I ordered one of those cool looking PVC catch cans off ebay, should arrive by tomorrow. I never felt I needed one but I have been meaning to get one because they look high tech. Only $16.75 including shipping.

http://www.ebay.com/itm/260885562648?it ... 20&vxp=mtr

[marlinh]

I have been having similar problems with an engine I recently re-ringed. In my defense I put this engine together after going through 4 months of chemo and my brain was not fully functioning. Anyway, the engine was for my winter driver. I honed the cylinder walls, put in new rings and connecting rod bearings. The head I installed was one I got from a friend some time ago who had replaced all the valves and had the head machined. Previously, I had lapped all the valves, replaced valve stem seals and had it sitting around just for this purpose. I also seated the rings following the instructions carefully. Also, on that test drive, the cam seal walked out of the head too! Oil leaking everywhere! I installed one of another brand and it is okay.

I have oil getting into the air cleaner from the breather. If you take the hose off the valve cover with the engine running, you can see droplets of oil and vapour coming out of the head. I pulled the valve cover off and checked the baffle. Tried another pcv valve from another engine and it is still doing it. Oil level is not overfull. When you rev the engine with the oil filler cap off and your hand over it, you get suction like you should with new rings.

I have thought that maybe I installed a ring upside down, but that oil would then be burnt in the exhaust. Any suggestions? I know I shouldn't have tackled that job considering my circumstances, but the old engine was such an oil burner, I didn't want to drive it another winter like that. 1 liter of oil every 500 km or so. I was under pressure to get the job completed because I was leaving for more treatments and needed the car done.

Also, another knock on the head, my mint summer car, Everett, was carefully stored and parked for the winter. And while I was away, a heavy snowfall caused a tree to come down and hit the car. It now has a concave roof! I had thankfully put storage insurance on it, since I was having a bad year it seemed a good idea at the time. My battle will be with ICBC to see if they will fix it. Over the phone they told me they would probably write it off, considering it's age.

Any suggestions on the oil problem?

[Petros]

Usually the symptoms would indicate high crank case pressure. It will cause the oil build up in the air filter and sometimes the seals to push out (as you experienced). have you done a compression check on it? Also, try a brand new PVC valve, and verify that all of the pvc system is connected properly and functional.

But you say it has a vacuum on it when it is reved? that would indicate it has little/no leakage. You might just make temp catch can for the breather. I used a plastic oil container (the kind that you get when you buy 4 liters of oil), ran the breather hose into the container that was bungee corded in place in the engine compartment. I did it as a temporary measure, you can also buy permanent ones (they do not cost much).

like this:

[Petros]

sorry to hear about your health issues, our best wishes and prayers for a full recovery.