Oil mist in cabin

polarman · August 14, 2011, 09:52 AM

When I'm running at cruising speed, I have alot of oil mist coming in through the heat ducts.Not so much going up or down hills.I replaced the PCV valve and gave it a tune up, but have yet to test drive it. The old PCV valve didn't appear plugged up, so I doubt that I've fixed the problem yet.
Any thoughts?

brians69d24 · August 14, 2011, 02:45 PM

Are you sure it's not coolant mist?

Oz · August 14, 2011, 10:13 PM

With our first classic Winnie, the Winne-Beast, we had the same thing, although it wasn't all that heavy, it was noticeable. Then, on a trip in which we went through 3 tunnels, at the next stop, I noticed that there were a zillion, tiny oil droplets on the side of the rig. I found an oil leak in the front of the engine and figured that the engine fan was blowing it back. The tunnel simply made it turn back and hit the rig. Just an observation from a personal experience.

polarman · August 15, 2011, 02:42 PM

Quote from: brians69d24 on August 14, 2011, 02:45 PM
Are you sure it's not coolant mist?

Absolutely sure. I don't see any oil leaks on the engine, so I'm pretty sure it's from the PCV system. If the new PCV valve didn't fix it, I will just plug it off at the carb and make a catch can to vent it under the rig somewhere. Hopefully, I can test drive it today or tommaro, but it's raining cats and dogs right now so time will tell.

ibdilbert01 · August 15, 2011, 03:26 PM

I'm not sure how a PCV valve leak could possibly mist into the ventilation system while moving, unless there were some changes with the heating / duct system on later models. On my 72, the cabin fresh air intake is on the passenger side, above and in front of the radiator.

DaveVA78Chieftain · August 15, 2011, 07:13 PM

Do you by chance have a aftermarket transmission cooler in front of the radiator that is leaking?

Dave

DaveVA78Chieftain · August 16, 2011, 09:03 AM

I take it you are thinking PCV valve because the oil fill / air breather is located adjacent to the fresh air intake. That is entirely possible if the PCV valve is not opening up. All you have to do to test the PCV is pull it out of the valve cover with the engine running and place your finger over the end of it to see if there is a strong vacuum. It is just pulling oil fumes from the engine.

Dave

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polarman · August 17, 2011, 02:25 PM

That picture highlights the problem. I removed the oil filler last night after still having the problem while driving. It seems that the oil mist is coming fron the filler, which is directly in front of the air intake for the cab heating system. Now I will have to remove the engine cover to put oil in it, but that's better than oil blowing into my kids faces.
So, now I have the right head vented into the air cleaner. If it runs crappy, I will have to vent it under the RV, but that should be the end of my oil mist problem.
Thanks for the input fellas!

DaveVA78Chieftain · August 17, 2011, 02:31 PM

Just rememeber, that most likely means you have oil ring blow by on one or more cylinders.

Dave

polarman · August 31, 2011, 02:24 PM

That is possible, but I will check the ubrella seals on the valves first. That would be a much cheaper and easier fix if they are shot. I might even have some 318 valve cover gaskets kicking around my garage, so it won't cost much to check the seals.