What causes varnish to begin building up?

[Tom NJ]

Varnish formation is a high temperature oxidation process (polymerization) which is often triggered or aggravated by highly unstable components in the blow-by gases, such as partially burned fuel. A weak oil in a hot engine can also contribute once the anti-oxidants are exhausted.

Tom NJ

 

[Shannow]

Originally Posted By: INTJ


Informative, but what about the in between stuff?

E.g., I have varnish in my top deck along with the barnacled hard crusties or carbon. I didn't have any typical sludge, btw.

The heat coked something on the valve train.

So, I wonder what is the chemical dymanic here?


Bear in mind that the location that the varnish product formed isn't necessarily where you find the varnish.

As oil containing varnish cools, the varnish can become insoluble and drop out.

 

[INTJ]

Ah, the troubled area( the eventual coke spot) on the top deck cools or is exposed to a drop in temp.

So, the localized colder spot is the catalyst area for the carbon sticky.

I guess this carbon "area" grows like a thermal blanket. It starts small as you get a small localized spot via "less heat," and this carbon further insulates heat conduction around that spot and causes the 'snow ball rolling down the hill' effect, as the saying goes. Similar to the effect of a stalactite in a cave.

?

 

[Merkava_4]

Originally Posted By: OldCowboy

Pablo and Shannow are arguing about the same thing. Shannow about the chemical reaction and Pablo about contributing factors.


LOL!! They were agreeing with each other but didn't know it.

 

[Pablo]

Originally Posted By: Merkava_4
Originally Posted By: OldCowboy

Pablo and Shannow are arguing about the same thing. Shannow about the chemical reaction and Pablo about contributing factors.


LOL!! They were agreeing with each other but didn't know it.

Heck yeah. I'm just jealous he is having summer. Fracking cold here and talking about schnow. And I got flustered and forgot to even mention the effect of nitration. Bad mojo.

 

[JAG]

In addition to what's already been mentioned, the metals in an engine act as catalysts for oxidation of the motor oil. Steel, aluminum, copper, and brass are all catalysts, to varying degrees.

Water causes bad reactions to occur in motor oil: http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=842343&page=1

Articles below are very good:
http://www.machinerylubrication.com/Read/268/oil-sludge-varnish
http://www.machinerylubrication.com/Read/874/sludge-varnish-turbine
http://www.machinerylubrication.com/Read/59/oil-analysis-varnish

 

[4ever4d]

It is Friday the 13th bad mojo day anyhow!

 

[fpracha]

Originally Posted By: Tom NJ
Varnish formation is a high temperature oxidation process (polymerization) which is often triggered or aggravated by highly unstable components in the blow-by gases, such as partially burned fuel. A weak oil in a hot engine can also contribute once the anti-oxidants are exhausted.

Tom NJ

So if we see "black smoke" in the exhaust at high revving, it means a high blow-by definitely exists and so does a very high probability of varnish deposits either "already formed" or "to have begun to form and deposit" ?

 

[Tom NJ]

Blow-by always exists, but if you have frequent black smoke it would indicate inefficient fuel burning and more partially burned gas entering the crankcase, which may overcome the oil's additives and lead to sludge and/or varnish deposits.

Tom NJ

 

[TFB1]

Black smoke indicate incomplete fuel burning, too rich air/fuel ratio is one cause, another could be poor iginition... In either case the engine won't be performing as it should...

 

[ltslimjim]

^I've got white smoke at times at 90 in 3rd.

 

[steve20]

try 4th

 

[ltslimjim]

Originally Posted By: steve20
try 4th


My thoughts were similar, I wonder if varnish is being forced off of the valve springs at those speeds? I doubt the car has been driven that hard in years if ever.

 

[fpracha]

Originally Posted By: ltslimjim
Originally Posted By: steve20
try 4th

My thoughts were similar, I wonder if varnish is being forced off of the valve springs at those speeds? I doubt the car has been driven that hard in years if ever.

Yes Indeed, I'm also very interested to know if the sludge (dark orange soft stuff) seen at the oil filler cap area (and below the rocker cover area & valvetrain) will be cleaned up when driving at 90 in the 4th ?
OR will the sludge not move at all and lead to Varnish ?

 

[ltslimjim]

^well, when I get my valve cover removed for some pics I'll let ya know.

 

[DragRace]

Originally Posted By: ltslimjim
^I've got white smoke at times at 90 in 3rd.

This happen alot? This sometimes is the sign of a blown head gasket or possibly a crack in the head, intake or cylinder.

 

[ltslimjim]

Originally Posted By: DragRace
Originally Posted By: ltslimjim
^I've got white smoke at times at 90 in 3rd.

This happen alot? This sometimes is the sign of a blown head gasket or possibly a crack in the head, intake or cylinder.


Haven't taken it up to 90+ MPH often.

Not sure, this was after stop 'n go driving for about 10 minutes, idled for 5-10 at a drive-thru, then hopped on the freeway. Punched it up to 80+, then when it was 90 MPH and in 3rd it began to expel white smoke(new clutch?), seemed to do it more the harder I accelerated. Seemed really white, if any other color at all 'perhaps' slightly darker than straight white?. I've checked UOA before(no coolant) and a compression test 2 years ago when the engine was purchased, it passed...maybe the intake or head/cylinder is cracked??? It loses 1 quart every 3,000 miles.

Seems to drive fine, though...and UOA show good results.

 

[DragRace]

Originally Posted By: ltslimjim
Originally Posted By: DragRace
Originally Posted By: ltslimjim
^I've got white smoke at times at 90 in 3rd.

This happen alot? This sometimes is the sign of a blown head gasket or possibly a crack in the head, intake or cylinder.


Haven't taken it up to 90+ MPH often.

Not sure, this was after stop 'n go driving for about 10 minutes, idled for 5-10 at a drive-thru, then hopped on the freeway. Punched it up to 80+, then when it was 90 MPH and in 3rd it began to expel white smoke(new clutch?), seemed to do it more the harder I accelerated. Seemed really white, if any other color at all 'perhaps' slightly darker than straight white?. I've checked UOA before(no coolant) and a compression test 2 years ago when the engine was purchased, it passed...maybe the intake or head/cylinder is cracked??? It loses 1 quart every 3,000 miles.

Seems to drive fine, though...and UOA show good results.


Keep an eye on coolant and oil.