rotoboy661

hey guys i was going to polish my oil cap and i saw the weirdest thing

i saw some foaming inside of the oil filler neck

smells like gas

what could it be?? leaky injectors???

is that bad??

thanx
mike

gdnimr0d

iTrader: (4)

hmm hard to say...i have seen it in my motor and friends motors before...and i have never noticed a problem from it...keep us posted if you do find a way to get rid of it from forming

rotoboy661

well my car ran fine before i discovered it

i was just curious

Kento

It's basically moisture condensation inside the filler neck and engine cases mixing with the oil sloshing up from the engine, creating a milky foam. The fuel smell is from fuel dilution in the oil caused by blowby. Nothing to really worry about, unless you're losing coolant.

DaleClark

iTrader: (55)

All rotaries do this. The RX-8 guys are freaking out about oil cap foam as well . It's just condensation trapped at the high point in the system - totally normal, nothing to worry about.

Dale

Enconsiderate

yea mike,

as kento and dale have said, its nothing to worry about. i am surprised it took you this long to notice that.

rotoboy661

haha thanx ian

nah it didnt bother me

i was just asking how it developed

thanx fellas

reza

hmm....butter....

Nghtstlkr7

happened to my FC after it sat for three months... she ran fine afterwards. dont sweat it.

poorboyracing

Its rotor nutt

Robbierx7

iTrader: (1)

i found this on a maintenance schedule and troubleshooter guide

Concerning moisture in the oil cap, I found the O-ring that goes between the plastic oil filler neck and the engine is the culprit, also check the O-ring around your oil cap, as I am sure you are aware, these O-rings ware out, one of their roles is to prevent moisture from entering the system. Unfortunetly the first O-ring I mentioned is not an easy item to reach (surprise surprise). Wael El-Dasher <wael.el-dasher@yale.edu>

Robbierx7

iTrader: (1)

i have the same problem on my fd..but mine is more of a mustard colour.

rotoboy661

yeh same thing on mine

CantGoStraight

If it's just from moisture it won't smell like gas. Leaking fuel injector would be my guess unless your getting some thing going on with the charcoal canister ? ? ? ?

Kento

With all due respect to Wael, "prevent moisture from entering the system"? There is going to be moisture in the oil cavities and sump of a cold engine no matter what you do, because it must have some venting to the atmosphere eventually. The o-ring's primary role is to prevent oil spray from leaking out, not moisture leaking in (although, a proper seal so that the crankcase vents properly is also a good thing).

Kento

But if it's mixed with the oil from your crankcase (which it must be, residing in the filler cap) that has already been contaminated with gas from blowby, it will smell like fuel.

f/p79

I had quite a lot in my first gen 13B autocross car. Now there is rust in the filler neck. THAT scares me.
Anyone have any luck in removal that that stuff?

Jim Calandrella

I had that mustard foam from the very first day I had my reman. I noticed it, but never really thought anything of it, as the motor was new.