Conventional oils and varnish

[StevieC]

Originally Posted by Trav
That is on a 5K synthetic OCI. People here went nuts when I first posted this issue with some Honda engines almost 10 years ago then a few years later more and more started showing up.
Toyota 3.0 had bad problems, so bad in fact Toyota had a TSB requiring 3K OCI with synthetic oil. Just because you don't see the varnish on the top end it doesn't mean the piston rings are not getting sticky so you cant make that statement either unless you are doing a compression test on every engine.

I did a low mile R32 with a spotless top end, it ran well but has universally lower compression than spec, an overnight piston soak brought it right back to spec and it stayed there with a shortened OCI.

Listen, lets not make this into something it's not. I posted the top end pictures as an example. Did I say not to check the bottom end? Did I say that it couldn't have issues for the pistons and their rings? No I didn't. I posted a lightly varnished engine which is NORMAL to see in A LOT of engines particularly Euro ones like BMW and it's perfectly fine with no hindrance to their operation. Are there some engines that are poor designs that can suffer from mild amounts of varnish? YES and I said that to TIG. BUT IT'S NOT THE NORM and quit trying to make a mountain out of nothing because you have your knickers in a knot over some of my posts you don't happen to agree with.

It's up to the OP to decide what is best for him and what may or may not be an issue. He shouldn't panic about some light amount of varnish simply because of a few engines with poor designs suffered from it when the majority do not suffer from it. The GM 8-cylinders are notorious for having heavier varnish resembling more like the first picture you posted than the pictures I posted and they go along just fine their whole lives. 0 issues.

Look at the right head

 

[Zee09]

Originally Posted by StevieC
Originally Posted by Zee09
Yeah but that sludge will never let the engine rust...…………..

And you will have a large supply of what resembles wheel bearing grease too.

And no rebate forms to fill out...……. free!

 

[StevieC]

Originally Posted by Zee09
Originally Posted by StevieC
Originally Posted by Zee09
Yeah but that sludge will never let the engine rust...…………..

And you will have a large supply of what resembles wheel bearing grease too.

And no rebate forms to fill out...……. free!

 

[Trav]

Here we go again, only 7 more pages to go.

 

[StevieC]

Originally Posted by Trav
Here we go again, only 7 more pages to go.


Feel free to get off your horse at any time. You started the nonsense.

 

[demarpaint]

I posted this picture a few years back of my 2000 Century, which my father owned since new, it was very well maintained with conventional oil at intervals that never exceeded 3,000 miles. The engine ran great, but looked like crap through the fill hole, and was evidence enough for me to continue not to use conventional oil. Flame suit on. The engine had about 80K miles on it.

 

[StevieC]

No flame suit needed IMO,

Some engines are better suited for Synthetic and some are fine on Dino. No arguement there. I use synthetic for this reason however I know that my particular engine runs just fine on conventional because of my dad's engine which is the same and has seen nothing but conventional it's whole life. It's over 300K and hasn't been touched and passes emissions testing and drives like it day the first day I had it before him.

Conventional has impurities in it. Albeit way better than they used to be but this can cause issues in today's higher stressed hotter running engines. Some OE's do a much better job handling this that others and it's why we see a variance as to what can cause problems for some small number of cases but doesn't in the majority of other cases.

 

[Astro14]

Originally Posted by StevieC
Originally Posted by Trav
Here we go again, only 7 more pages to go.


Feel free to get off your horse at any time. You started the nonsense.


The nonsense started with this inaccurate blanket statement:

Originally Posted by StevieC
Varnish won't hurt anything.


That you've now walked back, modified, and basically, retracted.

 

[StevieC]

Let me clarify for you Astro14, because I didn't walk it back.

Varnish won't hurt anything. It doesn't in the vast majority of engines out there I've rebuilt and taken apart more than I can count myself and with my dad of all makes/models/types etc. I assure you Varnish is a common occurence at all levels be it light, moderate, heavy.

The GM 8 cylinders have far heavier varnish on average from the ones I've seen than the lighter varnish in the spool valve picture Trav provided. This would indicate that it's a poor design of said spool valve susceptible to light varnish. The OE should have engineered it to either prevent varnish formation from operating that part at a lower temperature or specified a lubricant that could handle the stress placed upon it or allowed a tolerance for some varnish build-up to occur without affecting the parts operation. It was run on Synthetic so most likely if it was run on conventional it would also have failed seeing as conventional is inferior to synthetic in this regard. Why aren't all spool up valves failing then, surely this isn't the only varnished one given the examples I site from Euro engines that are usually lightly to moderately varnished Always...

Are there some engines and components that are a poor design where it can affect them, YES as I mentioned, that isn't the norm though. So therefore my comment reflects the NORM. Sorry for not having an asterisk and a disclaimer accompanying it with legal jargon. I'll be sure to consult my lawyer in future so that it's spelled out in the fine print so as to alleviate any misunderstanding.

I see Trav has a passenger on his horse.

 

[PimTac]

The problem for most is that varnish is usually discovered during repairs later on like a valve cover gasket replacement. At that point it may be too late.

Using a good quality oil from the start with prudent oil change intervals is the best most of us can do.

 

[StevieC]

Originally Posted by PimTac
The problem for most is that varnish is usually discovered during repairs later on like a valve cover gasket replacement. At that point it may be too late.

Using a good quality oil from the start with prudent oil change intervals is the best most of us can do.

Absolutely, but don't panic if it does appear as it's usually harmless.

 

[JAG]

Suppose it is true, and I think it is: varnish is sometimes a problem and sometimes, not. Therefore it is an incorrect statement that "it is harmless". We must be precise in our words or problems arise.

 

[StevieC]

Originally Posted by JAG
Suppose it is true, and I think it is: varnish is sometimes a problem and sometimes, not. Therefore it is an incorrect statement that "it is harmless". We must be precise in our words or problems arise.

This vehicle requires a 5w20 API licensed GF-5 oil changed at a maximum interval of 8,000 miles under normal driving conditions and 3,000 miles under heavy duty / severe service schedule (Or similar statement from the OE).
This is followed and varnish still occurs as pointed out in a lot of the GM V-8's I cited earlier. Which seems to affect it in 0 ways.

Look at the picture Demarpaint provided and it was changed at 3K miles and I'm sure knowing him that it was the correct oil the manufacturer calls for.

Does the OE need to specify an added section that says "Buy the oil that doesn't cause varnish as problems may occur, doesn't usually but sometimes does in rare cases"? By your similar logic they should.

Believe me when I tell you the average Joe doesn't stress about oil in their vehicle and it runs just fine varnish or not except in rare cases where a poor design has a problem with varnish but we have other cases where poor design leads to other problems too so how is that a fault of something can happen naturally and does in a lot of cases? It isn't. It's the OE's fault for either not specifying a lubricant devoid of varnish causing issues under all possible conditions or not designing the engines components to prevent varnish or allowing a tolerance for a reasonable amount of varnish to accumulate and still function.

Anyway I've said my piece and will agree to disagree here.

 

[PimTac]

Isn't varnish the beginning part of a process that eventually will lead to worse things? All this depends on the time frame. If a engine shows varnish at 30k miles then something needs to be done. If it's at 150k then it may be normal.

Some engines varnish up easier than others. For some it's only one portion that it occurs.

 

[StevieC]

Not necessarily. The BMW's seem to always have a light golden colour regardless of miles somtimes it's got a redish hue to it but I wouldn't consider it more heavy varnish, I think it's just oil chemistry being different leaving a different shade of varnish. The GM V-8's seem to get to the dark brown state and never accumulate more and I've seen these at 60,000 miles to upwards of 300K miles thanks to them always seemingly needing valve cover gaskets. Only place I've seen it really heavy is where oil wasn't changed when it should be and there was a regular occurrence of this. Maybe I got lucky and didn't see the other side of this but I doubt it with the thousands of vehicles through the door over the years.

 

[demarpaint]

Originally Posted by JAG
Suppose it is true, and I think it is: varnish is sometimes a problem and sometimes, not. Therefore it is an incorrect statement that "it is harmless". We must be precise in our words or problems arise.

True, and be very cautious when blanket statements are made. No StevieC this is not directed at you, it is a statement based on my observations over the years here.

 

[OVERKILL]

Varnish is the precursor to sludge. It is a sticky layer of precipitate that indicates that the contaminant carrying capacity of the lubricant was exceeded. It is generally deposited on cooler areas and/or areas of low oil flow, which is why the cylinder head surface is a common location to observe it. This also means that it has a propensity to build up in low-flow areas like ring lands where the lubricant is not in forced motion. Accumulation in this area results in oil control problems, which then present as consumption and can ultimately result in ring sticking, blow-by and loss of compression if it gets bad enough.

While engine designs are generally tolerant of a bit of varnish and thus typically asymptomatic, this should not cause one to thus conclude that varnish is harmless. Like many human maladies, the causes of which are well-known, an underlying condition that hasn't manifested into something impactful is still a condition nonetheless.

As I'm sure many recall, BMW reduced their OCI length due to issues they were experiencing, so I'd be wary of using that marque as an endorsement. As engines become more complex, various systems will, as Trav demonstrated, be less tolerant of this type of accumulation. Low-tension rings will be more inclined to stick for example, leading to consumption.

 

[PimTac]

Originally Posted by StevieC
Not necessarily. The BMW's seem to always have a light golden colour regardless of miles somtimes it's got a redish hue to it but I wouldn't consider it more heavy varnish, I think it's just oil chemistry being different leaving a different shade of varnish. The GM V-8's seem to get to the dark brown state and never accumulate more and I've seen these at 60,000 miles to upwards of 300K miles. Only place I've seen it really heavy is where oil wasn't changed when it should be and there was a regular occurrence of this. Maybe I got lucky and didn't see the other side of this but I doubt it with the thousands of vehicles through the door over the years.






I can believe this. I remember engines way back when that ran on Castrol GTX and they all had that orange hue varnish that mechanics said was typical of Castrol.

 

[dave1251]

Originally Posted by tig1
Originally Posted by StevieC
Varnish won't hurt anything.

Don't believe varnish is harmless. Varnish is caused by the oil oxidizing (thickening), as the oil is reacting to heat in an unfavorable way. This can also lead to ring coking with causes blow by. Use a quality synthetic oil and this won't happen.at 10K OCIs. I know. That's been my OCI for 41 years with Mobil 1 oils.

Ive been doing 10K OCI's with conventional which does not exist with no varnish. If there is any issues it's letting the oil run low.

 

[JAG]

Stevie, none of that response touched on my point. My point was that people should not make blanket statements that imply that there are no exceptions to it. It is easy enough to add qualifiers such as sometimes, generally, often, almost always to statements that make it known that there are exceptions due to dependencies. Even better is to state what some of those dependencies are.

My personal experience was varnish clogging an expensive and long section of PCV hoses as well as partially clogging the oil pickup screen. 2003 VW 1.8T. I paid over $500 for new PCV hoses and valve, including labor. Next time it clogged, I cleaned it manually as best as I could.