What causes varnish?

[akhristov]

Hey guys,

I've been wondering... What causes the yellow-ish varnish inside engines, and what can I do to prevent my car from getting it?

I'm running either Mobil 1 or Red Line (depending on availability) in my car right now. Would that pretty much keep varnish from forming, or is it going to happen anyway?

 

[calvinnnnnnnnn]

varnish does not harm to your engine.....its inevitable in some engines

 

[terrapin10]

From what I can remember, varish is the result of heat on motor oil.The heat causes the oil to "stain" the engine. Particularly on non moving parts. Motor oils without the appropriate blends additives such as detergent and acid neutralizers can form excessive sludge and varnish. Today's high quality synthetic oils will minimize sludge and varnish. 20 years ago, it was a challenge.

 

[Hethaerto]

Varnish is caused by Castrol GTX.

 

[scurvy]

Originally Posted By: akhristov
I've been wondering... What causes the yellow-ish varnish inside engines, and what can I do to prevent my car from getting it?


Exposing the innards of the engine to light will cause a harmless layer of varnish to immediately crystallize & bond to engine components. It is from the photophobic compounds that make up the base oil. This is a similar phenomenon to tordadoes being produced by the presence of thunderstorms, trailer parks & news crews.

The best way to prevent your car from getting it is to not take off the valve covers to look, or even peek down the fill hole. Pour in high quality oil, install a good filter & run them to a reasonable OCI - which it sounds like you're already doing.

Drive more, worry less.

 

[Hokiefyd]

Originally Posted By: scurvy
Exposing the innards of the engine to light will cause a harmless layer of varnish to immediately crystallize & bond to engine components. It is from the photophobic compounds that make up the base oil. This is a similar phenomenon to tordadoes being produced by the presence of thunderstorms, trailer parks & news crews.

 

[MolaKule]

Please check out this thread on the discussion of lacquer and varnish formation in engines:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=530841#Post530841

 

[ekpolk]

I'm more interested in whether there's a realistic way to get rid of varnish, it's there, without tearing the engine apart and tanking all the parts. Anyone?

 

[tig1]

Since I have not had an engine fail since my old 66 straight 6 Chevy in 1970, I haven't seen the innards of one except through the oil fill hole.(head gasket replaced on 85 Escort diesel which doesn't count) No visable varnish with my engines.

 

[ekpolk]

Mostly an academic question for me. With the Prius, which is now essentially my son's, we bought it with ~15k miles on it, Toyota certified. It had a very slight yellow cast to the metal visible in the oil filler, and which rubs easily off the top of the baffle (which is silver colored in this car). I've tried a variety of oils, and even an ARX treatment just for the heck of it, and there has been no noticeable change. Not worried about it; maybe jut mildly annoyed. But hey, I chose to buy it that way...

 

[ericthepig]

Originally Posted By: ekpolk
..It had a very slight yellow cast to the metal visible in the oil filler, and which rubs easily off the top of the baffle (which is silver colored in this car). I've tried a variety of oils, and even an ARX treatment just for the heck of it, and there has been no noticeable change...


Interesting that nothing (or at least that you've tried) is dealing with the soft stuff. Kind've disheartening.

 

[Mamala Bay]

Originally Posted By: ekpolk
Mostly an academic question for me. With the Prius, which is now essentially my son's, we bought it with ~15k miles on it, Toyota certified. It had a very slight yellow cast to the metal visible in the oil filler, and which rubs easily off the top of the baffle (which is silver colored in this car). I've tried a variety of oils, and even an ARX treatment just for the heck of it, and there has been no noticeable change. Not worried about it; maybe jut mildly annoyed. But hey, I chose to buy it that way...


Not many vehicles with 15K has varnish on it being subjective...makes me wonder on the hybrid engines...does it produce enough heat being in electric mode. Just thinking.

 

[ekpolk]

Originally Posted By: Mamala Bay
Originally Posted By: ekpolk
Mostly an academic question for me. With the Prius, which is now essentially my son's, we bought it with ~15k miles on it, Toyota certified. It had a very slight yellow cast to the metal visible in the oil filler, and which rubs easily off the top of the baffle (which is silver colored in this car). I've tried a variety of oils, and even an ARX treatment just for the heck of it, and there has been no noticeable change. Not worried about it; maybe jut mildly annoyed. But hey, I chose to buy it that way...


Not many vehicles with 15K has varnish on it being subjective...makes me wonder on the hybrid engines...does it produce enough heat being in electric mode. Just thinking.


I suspect more like the first owner/lessor didn't change oil enough. It is now 80k miles, and the very light varnish has really not changed. And none at all in the TCH.

 

[Pablo]

Originally Posted By: akhristov
What causes varnish?


Quote:
Varnish is largely formed from fuel components.