Varnish in engine

[paulri]

Is it a cosmetic issue only, or can it eventually cause the engine to seize up?


I’ve seen pics that guys here post when they take off the valve cover, and I see moderate amounts of varnish, and people argue about whether that amount is ok or bad. I just wonder about the significance of a slight amount of varnish. Is it possible that that could cause engine failure, or would it have to be a major case, before it would cause engine failure.

 

[barkingspider]

Varnish is only cosmetically bad in an engine. It will not cause it to fail

 

[sw99]

Varnish is fine happens all the time. Some cars its unavoidable.

 

[Merkava_4]

Varnish can cause piston rings to seize up in their ring lands preventing them from free floating and sealing against their mating cylinder bores. Massive amounts of blue smoke and oil consumption is the result of that. I can post a YouTube video explaining that upon request. Varnish can also cause camshaft phaser solenoids to seize up resulting in unadjustable valve timing. I can post a YouTube video about that too.

 

[paulri]

Originally Posted By: Merkava_4
Varnish can cause piston rings to seize up in their ring lands preventing them from free floating and sealing against their mating cylinder bores. Massive amounts of blue smoke and oil consumption is the result of that. I can post a YouTube video explaining that upon request. Varnish can also cause camshaft phaser solenoids to seize up resulting in unadjustable valve timing. I can post a YouTube video about that too.


These things you are talking about---we're not talking about the moderate amounts of varnish seen in pics here, but of extreme instances?

Yes I'd love to see a video showing what you are talking about.

 

[tig1]

Varnish is not harmless. It can lead to ring coking and problems with cam phasers. Also engines with OHC timing chains, the oiling ports for the chain guides can become clogged with varnish and restrict oil flow to the guides and chain. The cleaner your engine stays the better it is for the engine.

 

[Nick1994]

Heavy varnish where it's disgusting in there probably isn't the best thing.

Light varnish is just fine, no worries.

If you'd like to try to clean it up little by little, change your oil a little more often.

 

[FCD]

A light gold colour is ok, if it looks more brown ish then it's bad , post pictures

 

[Merkava_4]

Originally Posted By: paulri
Yes I'd love to see a video showing what you are talking about.


Toyota 1.6/1.8L Oil Burning -'96 Geo Prizm -Part 2 of 4
Fast forward to 15:00

Ford 4.6L 5.4L 3v Engines: VCT Solenoid Replacement
Fast forward to 4:00

 

[Lubener]

Don't get caught up in the foolish varnish stuff.Won't hurt a thing.

 

[paulri]

Originally Posted By: Merkava_4
Originally Posted By: paulri
Yes I'd love to see a video showing what you are talking about.


Toyota 1.6/1.8L Oil Burning -'96 Geo Prizm -Part 2 of 4
Fast forward to 15:00

Ford 4.6L 5.4L 3v Engines: VCT Solenoid Replacement
Fast forward to 4:00


Thanks for the links. Compared to what I've seen here, and to the comments to the pics, I'm pretty sure the Toyota engine would have been identified as having a lot of varnish---but the Ford looked like valve trains that are said to be in pretty good shape. Right at 4:00 he takes the valve cover off and you can see---not too much varnish there.

EDIT: the Prism is a 4 part series. You can see at 21:30 of the first Prism video (https://www.youtube.com/watch?v=AHDzgywlBro) where he takes off the valve cover.

 

[Alex_V]

Originally Posted By: FordCapriDriver
A light gold colour is ok, if it looks more brown ish then it's bad , post pictures


This. If it's just a gold sheen on internal parts it's not hurting much. If it's an obvious layer of gunk coating the internal parts, measures should be taken to reduce it. On an old engine I bought used I don't worry about getting it spotless inside, but on my Cruze (bought new) I'm keeping an eye under the valve cover and trying not to move my OCI to longer than what my oil can keep deposits at bay - from 0 to 50,000 I'd run Valvoline Synpower @ 5,000 mi. OCI and everything visible through the oil fill cap was bright and shiny. After 50K and moving up to Schaeffer's full syn @ 7,500 mi. OCI, and the car seeing more short trip and city driving lately, I'm seeing little whisps of deposits forming that may spur me to move back to 6,000 miles or so until its driving schedules trend back toward longer trips.

 

[paulri]

When you say you are keeping an eye under your valve cover, do you mean you are actually removing the cover? Or just looking under the fill cap?

Just curious.

 

[Merkava_4]

As usual, I'm the soul holdout in a varnish thread. Any amount of varnish at all is not good. The stuff is very sticky on surfaces that would otherwise be better lubricated if the varnish wasn't there. It blocks off oil return holes in pistons and freezes up cam phasers. And then last but not least, it looks horrible.

 

[Jetronic]

Originally Posted By: paulri
Originally Posted By: Merkava_4
Varnish can cause piston rings to seize up in their ring lands preventing them from free floating and sealing against their mating cylinder bores. Massive amounts of blue smoke and oil consumption is the result of that. I can post a YouTube video explaining that upon request. Varnish can also cause camshaft phaser solenoids to seize up resulting in unadjustable valve timing. I can post a YouTube video about that too.


These things you are talking about---we're not talking about the moderate amounts of varnish seen in pics here, but of extreme instances?

Yes I'd love to see a video showing what you are talking about.


What you see there is the precursor. The coolest spots of the engine get it first (inside of the valve cover usually but also inside oil coolers!), but if things get a little bit worse from there it spreads to moving parts. Later it'll turn to sludge or even hard carbon.

So yes, varnish on the valve cover is semi harmless, but cooling is affected which accelerates the formation of more varnish. If you spot it, rethink your oil change strategy, imo. Either a more oxidation stable oil is required, or a shorter oil change interval.

 

[Jetronic]

Originally Posted By: tig1
Varnish is not harmless. It can lead to ring coking and problems with cam phasers. Also engines with OHC timing chains, the oiling ports for the chain guides can become clogged with varnish and restrict oil flow to the guides and chain. The cleaner your engine stays the better it is for the engine.


Slider bearings don't like it eithzer, but luckily they're the warmer parts of the engine so not the first to suffer.

 

[Alex_V]

Originally Posted By: paulri
When you say you are keeping an eye under your valve cover, do you mean you are actually removing the cover? Or just looking under the fill cap?

Just curious.


Just peeking with a flashlight down the fill cap, which is in the very corner of the cover. Haven't had to remove the cover for the PCV valve or gasket gremlins yet!

 

[CorvairGeek]

I'm surprised that no one has pointed out that a chunk of the screen (which failed and broke) is probably in the VCT solenoid, and the Toyota appears to have been ingesting coolant on the number 3 cylinder (look at the clean piston). It still has a cross hatch pattern and no significant cylinder ridge at a 1/4 of million miles!