Last night I was screwing around and decided to remove the MEVI "resonance chamber" cover (where the butterfly valves are located). Low and behold, there was oil that had pooled up around the base of the two far passenger-side butterfly valve ports. I found this interesting because with the USIM, the two far passenger-side runners/ports also typically show oil saturation. The amount of oil I saw was around 1/2 a teaspoon. My PCV valve is in perfect running shape.

Just thought I'd share.



Dave

 

So does this mean we'll have to do a 6 month check to clean it?

 

EGR??

 

Oil residue might be coming from the valve cover breather tube that attaches to the midpipe.

 

Yep.

 

Maybe, but when I did my MEVI install, my EGR tube was very clean. I know some people's EGRs were completely caked with carbon and such. Seeing that oil saturation seems to be common in the two far passenger intake runners, I believe that instead of coating the runners like it does in the USIM, the oil (while in a small particulate size), slips by the butterfly valves during normal driving and begins to accumulate in the resonance chamber. It wasn't a huge amount of oil be any means, I just found it interesting that it was there. It's possible that when the butterflys open, the oil could be moved and sucked back down into the engine.

Where does this oil come from? It probably comes from a combo of the EGR, PCV, or valve cover breathers. Why does it accumulate on the far side of the engine? Probably because air velocity is lower on that side, especially during start-up and low rpm cruising.


Dave

 

hmmm. very interesting find indeed.

 

i noticed this about 2 months ago, but since my car has close to 190K, I figured it was pretty normal, so I didn't say anything.