Oil consumption increase - oily intake (1 Viewer)

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Jan 1, 2016
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AK
Good morning,

I am wondering if anyone has any further ideas of tracking down my oil consumption issue. I went from using a quart every 1500 miles to a quart every 200-400 miles. No smoke out the tail pipe, no substantial leaks on the ground ( rear main seal has a leak but it can't be in the amounts we are talking). I pulled the intake boot yesterday and the throttle body and boot were full of oil. I did a compression test and my numbers were all between 184-190. Spark plugs were dry. PCV valve is a year old and seems to be working properly. Most of my vacuum hoses are new. I was thinking of checking the vacuum with a gauge and possibly looking for leaks there. The valve cover spark plug gasket seems kind of oily when I pulled the ignition lead out. Possible leak through there? Any thoughts would be appreciated. 1994 1FZ-FE.

Thanks
 
Valve stem seals are a possible culprit if they're original to the vehicle, then the PCV valve sucking up too much oil, then other external leaks (oil pump cover gasket, distributor O-ring, valve cover gasket, spark plug tube seals, upper oil pan arch seal (less likely the rear main seal).

IME if the valve cover oil baffle is full of sludge (restricting drainage back into the engine) then oil can pool allowing the PCV valve tip to suck more into the intake.

Consider installing an oil catch can, that will give you an idea of how much is being sucked up by the PCV system.

How many miles on your 80?
Any work done (head gasket)?
What brand/viscosity oil are you using?
 
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Valve stem seals are a possible culprit if they're original to the vehicle, then the PCV valve sucking up too much oil, then other external leaks (oil pump cover gasket, distributor O-ring, valve cover gasket, spark plug tube seals, upper oil pan arch seal (less likely the rear main seal).

IME if the valve cover oil baffle is full of sludge (restricting drainage back into the engine) then oil can pool allowing the PCV valve tip to suck more into the intake.

Consider installing an oil catch can, that will give you an idea of how much is being sucked up by the PCV system.

How many miles on your 80?
Any work done (head gasket)?
What brand/viscosity oil are you using?

I've replaced the oil pump cover gasket, dizzy o-ring, main front crank seal. Valve cover gasket appears to be dry. The upper oil pan arch seal could very well be the leak appearing down on the bellhousing.
I'm sitting at 195k miles, as far as I know its on the original head gasket, but I have no proof of that. I've done a pretty thorough baseline all in the last 15k miles. I'm running valvolene full synthetic high mileage in 10w30. A catch can seems like a good idea, that way I would know how much is getting through there.
 
Sounds like valve stem seals. Even though its got relatively low mileage they are nearing 30 years of age so very likely gone hard
Try letting it idle for a few minutes and then give it a decent rev and see if any smoke out the tailpipe or coast down hill and then look in your mirror for smoke upon acceleration
 
Try the above at night with a vehicle behind you, easier to see the smoke cloud in the rearview mirrors with headlights shining from behind. FWIW
 
Thanks for the ideas. I will give them a try and go from there.
 
I checked my vacuum last night and am running nearly 20". So no leaks there. Trying to find a good time to do the smoke test, the cold weather here makes it hard to tell what is what.
 

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