94 s-10 Blazer with Vortec, CPI injection. Replaced the injector, FPR, and nut kit. Solved that problem but it seems to be pushing oil back into the plenum somehow. Any one ever had this problem? Doesn't seem to be affecting the way it runs but I would like to have a dry plenum if possible. Thanks...

 

Is there actual liquid oil in the plenum or is it just black oily build up? If the latter then that's normal.

 

does it have EGR? if so i would guess that a bad valve seal or rings are letting oil get by then the EGR is putting it back in the intake. is your exhaust smoking? are you loosing oil on a regular basis?

 

It does look more like a black liquid substance, but still feels like oil when I dab my finger in it. Truck does not smoke, the EGR valve and gasket have been changed. Sometimes it has a miss in it after it warms up but otherwise it runs fine. If it's normal for the black substance to be in there do you have any idea what it is...? Thanks for the replies.

 

That's what normal plenum build up looks like. If it's actually a liquid then thats oil not build up and Ryanmatt135 didn't say anything about the EGR valve being bad. If the valve seal or rings are bad then they can leak oil into the exhaust which the EGR can then feed back into the intake.

 

Thanks for the pick. It's actually oil puddled in the bottom most areas of the plenum. I can dip my finger into it. It doesn't smoke at all unless it's really cold out, wich is normal. Any ideas...? Thanks

 

MAN! thats a damn fine looking plenum. Very very nice. I'd like to meet the owner of that particular plenum and give him access to my bank account for all of his hard work....

anyway, it could be fuel puddled up on the crud built up in there.
this may sound dumb, but dip a q-tip in and see if it burns easily. if it does, it = fuel. if not, well, oil wont light easily

NOTE: do the actual burn test in a controlled area away from your semi disassembled engine

 

spyderlock, in case you didn't get the sarcasm thats ABN31B's plenum lol.

Anyway do the burn test, if it doesn't burn come back and we'll hit the drawing board agian...

 

Sweet plenum! I tried the burn test and it didn't burn, good idea though. The air intake tunnel closest to the back on the passenger side is very wet inside. I would say whatever is coming into the plenum is coming up that way. I'm having an EGR code no.32 pop up every few days now also. When it activates the service light the engine starts surging and trying to stall. I can remove the code by taking the battery ground off and it'll run great for a few days, until the code pops up again. Replaced the EGR valve last week. Sound like a computer problem to you?

 

Any more replies to this one, watching it closely.... Someone??