oil in air intake box???

[cameron 1]

I have a 1988 GL wagon with the 1.8 spfi engine and i changed the oil to day and air filter and the air filter has oil on it and the air tube to the engine has oil in it as well what does this mean does anyone know the car still runs great no blue smoke out the tail pipe :banana:

[screwbaru2]

I have a 1988 GL wagon with the 1.8 spfi engine and i changed the oil to day and air filter and the air filter has oil on it and the air tube to the engine has oil in it as well what does this mean does anyone know the car still runs great no blue smoke out the tail pipe :banana:

 

change your pcv check pcv hoses for blockage.

[McDave]

change your pcv check pcv hoses for blockage.

 

And if that doesn't fix it, you probably have too much blowby past the piston rings.

[cameron 1]

ok thanx guys ill change the pcv valve but its probably blowby i didn't think it would put oil in the air box but u learn something new every day

i think its problby blowby because my car has 299030 on the clock but pcv valves are easy so its worth a shot

[GeneralDisorder]

ok thanx guys ill change the pcv valve but its probably blowby i didn't think it would put oil in the air box but u learn something new every day

i think its problby blowby because my car has 299030 on the clock but pcv valves are easy so its worth a shot

 

It's not blow-by. That can't lead to oil in the airbox - only in the exhaust. The engine is an air pump and the valve work as check valves. As the engine runs air can ONLY go one way. Thus any oil introduced by the rings can only go out the exhaust valve. The ONLY place oil in the airbox comes from is the PCV system. Your valve is probably fine - it's the 300,000 miles of carbon and oil that's blocking the PCV hoses, fittings, and valve cover ports. You need to clean out all the hoses and fittings, and remove and clean the ports on the valve covers. And replace the PCV with one from the dealer (ONLY from the dealer) for good measure. Check EVERY connection, T, fitting, etc. Put them back how you found them and do the oil-burning-on-sweeping-left-hand-turns recall repair to keep them from getting munged up again so quickly in the future.

 

GD

[zukiru]

so what does a non-dealer one cause? since it came up?

[McDave]

It's not blow-by. That can't lead to oil in the airbox - only in the exhaust. The engine is an air pump and the valve work as check valves. As the engine runs air can ONLY go one way. Thus any oil introduced by the rings can only go out the exhaust valve. The ONLY place oil in the airbox comes from is the PCV system. Your valve is probably fine - it's the 300,000 miles of carbon and oil that's blocking the PCV hoses, fittings, and valve cover ports. You need to clean out all the hoses and fittings, and remove and clean the ports on the valve covers. And replace the PCV with one from the dealer (ONLY from the dealer) for good measure. Check EVERY connection, T, fitting, etc. Put them back how you found them and do the oil-burning-on-sweeping-left-hand-turns recall repair to keep them from getting munged up again so quickly in the future.

 

GD

 

Boy you sure got me thinking now as this goes against everything I've known about pcv systems in V and I engines over the past 38 years. Could it be because the OHCam H engine's valve train/cover area has no direct link to the crankcase, other than through the pcv system? Surely then the OHValve H engines could have blow-by to the airbox?

 

BTW... I just found your SPFI website. Great stuff!

[Erik R]

I had a similar problem 4 years ago. This kit was the solution for me. YMMV.

http://www.directcon.net/gmc248/Subaru/Instsheet_hi.jpg

http://www.directcon.net/gmc248/Subaru/PCV_modkit_hi.jpg

I have more detailed pics, if needed.

[GeneralDisorder]

Boy you sure got me thinking now as this goes against everything I've known about pcv systems in V and I engines over the past 38 years. Could it be because the OHCam H engine's valve train/cover area has no direct link to the crankcase, other than through the pcv system? Surely then the OHValve H engines could have blow-by to the airbox?

 

Hhhmmm - I'm not quite following what you are saying. There's always oil present in the valve covers due to the horizontal nature of the boxer engine. The PCV system (if it's not working correctly) will suck the oil into the airbox.

 

Blow-by is a fact of life for all engines. The PCV is there to deal with exactly this problem. Granted if there was *too much* for the PCV to handle then you might get a pressure build - but it would escape through the oil dipstick hole, and you would blow seals out, etc.

 

Experience over the years has shown that Subaru's engines just do not wear out their bore's.... virtually ever. Every single engine I've torn down had the factory cross-hatching still visible - even at 300,000 miles.

 

Further - the early EA82 SPFI's had a recall for exactly this problem as the PCV system was incorrectly designed from the factory and sucks oil on turns. His engine is a prime example of the pre-recall style PCV routing, and what it will cause over time.

 

Chances are very slim that the engine has any kind of blow-by that is above average and that the PCV can't deal with if it's clean and working correctly.

 

Cylinder/ring wear in the EA's is never seen - the bottom end will go twice over before the rings would wear out. I suppose it's due to the cylinders not being vertical and thus not tending to drain lubrication away from the wear surfaces. The lubrication is nearly perfect and thus the metal almost never touches.

 

BTW... I just found your SPFI website. Great stuff!

 

Thanks - It was a cool learning experience. Hope you find it useful.

 

GD

[cameron 1]

I had a similar problem 4 years ago. This kit was the solution for me. YMMV.

http://www.directcon.net/gmc248/Subaru/Instsheet_hi.jpg

http://www.directcon.net/gmc248/Subaru/PCV_modkit_hi.jpg

I have more detailed pics, if needed.

hey where do i get that kit do i have to go to subaru ?

and thnx guys for all the input:headbang:

[McDave]

Hhhmmm - I'm not quite following what you are saying. There's always oil present in the valve covers due to the horizontal nature of the boxer engine. The PCV system (if it's not working correctly) will suck the oil into the airbox.

 

Blow-by is a fact of life for all engines. The PCV is there to deal with exactly this problem. Granted if there was *too much* for the PCV to handle then you might get a pressure build - but it would escape through the oil dipstick hole, and you would blow seals out, etc.

 

Experience over the years has shown that Subaru's engines just do not wear out their bore's.... virtually ever. Every single engine I've torn down had the factory cross-hatching still visible - even at 300,000 miles.

 

Further - the early EA82 SPFI's had a recall for exactly this problem as the PCV system was incorrectly designed from the factory and sucks oil on turns. His engine is a prime example of the pre-recall style PCV routing, and what it will cause over time.

 

Chances are very slim that the engine has any kind of blow-by that is above average and that the PCV can't deal with if it's clean and working correctly.

 

Cylinder/ring wear in the EA's is never seen - the bottom end will go twice over before the rings would wear out. I suppose it's due to the cylinders not being vertical and thus not tending to drain lubrication away from the wear surfaces. The lubrication is nearly perfect and thus the metal almost never touches.

 

GD

 

Ok, that sounds better. In your original post it sounded like you were saying it was impossible for there to be blow-by. Confusion on my part ensued.

[Erik R]

Cameron 1,

That one in the pics I bought from the local Subaru dealer.

I got another kit from Pick-N-Pull, just looking through all the '91-older stuff. Just remove all the same parts, (they will require thorough cleaning) and install. Don't use your old PCV valve, just buy a new one.

 

http://www.directcon.net/gmc248/Subaru/pvc_mod.pdf (I don't know why PCV is spelled pvc........I found the file elsewhere and saved it as-is.