Asking For Trouble With Engine Flush?

82DMC12 · September 17, 2004

Hey Group,

I have a 94 ES300. The other day I replaced my PCV valve and grommet as preventative maintenence. I took a look inside the valve cover while the valve and grommet were out and noticed that it was very dirty inside - i put my pinky finger in and could feel really gritty dirt inside. The car has 104K miles on it - i got it when it had 83K. I have used Mobil 1 every 3000 miles since. I always run a quart of dino oil thru the engine and out the plug before refilling the crankcase, just to get as much old oil out of the pan as possible. The oil is still pretty clean looking even after 3K miles so I know i don't have much garbage where it counts. Is it worth it to use one of the many 5-10 minutes oil flush 'run before draining' additives out there or am I asking for some serious trouble with dislodged debris? Is this dirty crap inside the valve cover indicitive of some major neglect that will come back to haunt me? Or is this normal? If an engine flush treatment is OK, which one seems to work the best? I have noticed that when i remove my oil cap, what little you can see of the inside of the engine looks similar to what i saw under the PCV, only not quite as bad.

As an aside, this motor runs very clean, quiet, and sounds 100% perfect. I have no reason to believe it has any internal problems. I would hate to wreck it with a $5 bottle of cleaner.

Thanks for the opinions.

SKperformance · September 17, 2004

I use engine flushes every so often but iknow my engine is stron and have used synthetic since it was 2 years old and i had it.

You will find grit and dirt by the oil cap and pcv as they do not get contact with fresh oil ,only vapours which leave build up . This is to preent splashing of oil into the intake or out of the fill cap.

mburnickas · September 17, 2004

From what I have read it is a catch 22. If the sludge or junk inside is not bad, you are fine and it will clean.

If it is bad, then the cleaner might do its job but also block passages with the junk it is cleaning...

I would just use a synthetic with a good detergent package and let the oil do the cleaning. Just need to drain the oil a little sooner and maybe do an extra filter change.

SKperformance · September 18, 2004

I agree with mb on the loosenig on sludge but you are supposed to add it to hot engines so the chemicals slowly can work and disolve the crud slowly under heat to liquify it and be drained after.

It might be moer of a problem in loosening crud sealing oil form leaking from old gaskets more as it is commong with older engiens gettign a nice synthetic oil after build up of years.