Carbon under the filler cap --- arrgh!

[JohnBrowning]

My Dad had a 1993 V6 SR5 extended cab 4x4 and he neverhad this. He drove his 180 miles a day round trip to and from work. He ran Mobil 1 15w50 in it year round in Ga. From what I understand in the car and minivan applications their is a lack of airflow under hood. Terry was comenting once that the oil actualy cooks under the cam/valve buckets creating carbon and sludge. THeir has been a lot of disscussion on this in in the past. Trying searching sludge or sludge monsters.

I belive terry recomended Redline 5W30 and Lube Control. Lube control is a antioxidant/solvent complex. It increases the natural solvency of oils helping to prevent sludge while also giveing the oil some additional antioxidents. The additional solvency keeps the sludge polmers from binding preventing sludge. Redline oil is one of the most coke and sludge resistant oils.

It has been my experince that the Toyota V6's are wounderful engines but not as durable as their I4. The V6's usualy benifitt from shorter OCI's. I have seen plenty of them hit 200,000.

 

[richard612]

My 99 V6 Solara had the same crud under the cap. Popped the forward valve cover off at 29,000 miles and found a perfectly clean engine.

Don't worry about it.

RM

 

[cryptokid]

wait, how exactly does a pre cat disentegrate and cause cylinder scoring? cats and pre cats are located AFTER the cylinders. not before them.

 

[slider]

quote:

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Originally posted by richard612:
My 99 V6 Solara had the same crud under the cap. Popped the forward valve cover off at 29,000 miles and found a perfectly clean engine.

Don't worry about it.

RM

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Agreed. That area is inside the baffle, where there is no oil flow (unless you putting oil in) and just vapor cooking. It does not indicate the condition inside the engine .

 

[unDummy]

quote:

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Originally posted by cryptokid:
wait, how exactly does a pre cat disentegrate and cause cylinder scoring? cats and pre cats are located AFTER the cylinders. not before them.

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No EGR. Nissans with this problem need the ECU reprogrammed along with a more robust catalytic replacement.
Seems that the damaged catalytic is being sucked backed into the engine during 'high vacuum' complements of the CVVT.
This is one of the so-called benefits of variable cam timing/phasing--cleaner emissions which leads to engine death

 

[wtd]

Both my wife's 98 Pontiac Grand Prix and my 98 chevy truck has this under the oil fill cap. Both of these vehicles have run mostly Mobil 1 their whole life. I think this is caused because the oil filler caps are at the end of the fill tube and the oil film slowly bakes on the underside of the cap. I wouldn't worry about it.

Wayne