Many Questions about Varnish and Dino oils

[The Critic]

1) What is varnish in engines?
2) What does it indicate?
3) What is it caused by?
4) Will dino oils cause this if they are regularly run for 4-5,000 miles?
5) Can Auto-RX remove varnish?

I’m bringing this up since I saw one person on the forum say recently that dino oils cause varnish. Thanks for any input.

Michael

 

[LCD]

A little info per http://www.performanceoiltechnology.com/motoroiladditivesduringoilmanfprocess.htm

quote:

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Oxidation is the result of oxygen mixing with oil at engine operating temperatures. It is not so much the amount of oxygen absorbed by the oil that is important, but the amount of oxidation products formed. Oxidation causes an increase in oil viscosity as well as the formation of acids, resins, lacquers and varnish on internal parts, and especially on pistons and piston rings. More severe oxidation occurs as engine operating temperatures increase.

The effect of varnish, resins and lacquers on pistons and piston rings can cause a decrease in the amount of heat transfer between the piston and cylinder as well as stuck piston rings, leading to severe engine damage over a period of time. If the temperatures continue to increase to extremes then these deposits will continue to oxidize into very hard carbon type materials. When this hard carbon material meets with combustion residues and water, sludge is formed. Sludge can do further damage such as plug and block critical oil passageways and oil pump pick-up screens.

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Use LC20 (lube control) to control oxidation and remove varnish. www.lubecontrol.com

 

[Quest]

1 ~4: it's cumulative. Every lubricants when breaking down due to thermal stress, all causes varnish. Synthetics no exception with the exception that Synthetics can take on high temperature before breaking down.

5: I'm using it on my wife's car right now.

 

[TR3-2001SE]

1-3 have been fairly well answered above. 4. I think dino oil is more likely to cause varnish but probably not with a good dino and low milage changes. How low this milage has to be is anyones guess and I wish I knew. 5. auto-rx can remove varnish. We have seen pictures of this on this site. If the varnish is very heavy it may take more treatments to completely remove it.

 

[trooper99]

I'm on my second treatment of ARX right now. The first didn't seem to do much for the varnish I can see through the oil cap. Hoping the second treatment gets some of it. 100K on dino, mostly 3K changes. I'm switching to M1 soon as ARX is done. I also hope that it may remove some of the varish as well, as I've read in this forum, it should.

 

[Drew99GT]

I simply do not understand how people are getting varnish and sludge buildup in their engines with 3,000 OCI and dino All the engines I've been maintaining have had nothing but dino with 3,000 mile changes and they are all clean as can be; hardly even any staining of the metal occurs. I have used practically every brand of dino oil available. Maybe the secret is to mix it up on a routine basis (hey Paul!)

 

[1sttruck]

Type of oil also seems to determine potential for sludge and varnish, as the HDEO dinos don't seem to have problems with the hotter running turbodiesels provided the oil change intervals are adhered to. I guess it's because the current HDEOs are designed to keep contaminants in suspension so that they're either collected in the filter or dumped when changed, as opposed to despositing out as sludge and varnish, and because they have more agressive detergents to deal with anything that tries to deposit. HDEO synthetics seem to deliver even better resistance to degradation and the different base seems to provide an additional type of cleaning.

 

[Terry]

The issue is driven more by combustion chamber seal and PCV issues than the type of oils any more. Good seal and less gaseous blowby allows less build up.
This is where products like Auto-RX and Lubecontrol are WRONGLY dismissed as marketing gimmicks or overkill.

If you are fortunate enough to run relatively cheaper oils and change them often (3000) miles and your CC seal is good, you will wrongly think that it will last forever and all the noise here about these two adds is for naught.

Many different variables affect CC seal and efficiency and can throw that perfect balance and seal off. Allowing the development of varnish and build up. Syn oils are less volatile generally and will allow less rapid build up but still allow it. Also a syn that is not very solvent will over time leave a very hard varnish or deposit that is difficult to clean up.

Annual oil analysis can properly ID and correct the issue for the 90% of the engines I see that have problems. Applying the proper tuning and tools to correct the issue is the key, before problems compound.

 

[JohnBrowning]

1sttruck, Even though oils have been improveing a lot in the last couple of years it is not enough. Engines are running hotter then ever to try to get emissions in check asap! EGR functions are getting ever more agressive. People usualy do not care for their PVC system or EGR system at all until they fail! Add in things like neglecting air filter, spark plugs, high sulfur fuels, restrictive exhausts etc.... and you have a rolling varnish factory!

I also want to add that a lot of people are buying used cars and while you might take care of it you have no idea what the last guy did!

I did not have any luck with Auto-Rx on my 3.8 interms of removeing varnish! I think it was probably due to the low volume of oil that reachs a OHV engine! If it had been an OHC oil a much higher volume and pressure of oil would have been in the head and it would have been flung all over the place. Auto-Rx can not be expected to work in that environment. In my transmission on the other hand Auto-Rx removed so much varnish that the fluid looked yellow! Under close inspection it looked like someone dumped a pound of mustard seeds into the fluid! That was the varnish in suspension! Lube Control on the other hand worked great to get rid of the varnish that Auto-Rx could not get at in my Buicks head's.

I really like Lube Control for cleaning varnish!!

 

[1sttruck]

Also, it seems that varnish and sludge aren't reliably detected by the typical UOA, as we've seen some pretty good UOAs on engines that were sludging up pretty badly.

 

[TooSlick]

High levels of "nitration" (from NOx) also causes sludging - this is the specific problem Toyota has had with their 3.0L V-6 engine. High nitration is caused by excessive blowby, an EGR valve thats stuck partially open, or by excessively high cylinder head temps. Incomplete combustion and fuel/water contamination. generally results in elevated oxidation.

Use of AutoRX will significantly reduce oxidation/nitration in high mileage engines. In one case I saw a 50% reduction in Ox and a 75% reduction in NOx after the same # of miles on the oil....I'd call that pretty remarkable!

Terry - I'll get the hang of this eventually ...

TS

 

[1sttruck]

It looks like the standard Blackstone UOA doesn't include a seperate 'O/N/S ~tion' test, as they state that they rely on measuring insoluables. From what I've read an FTIR is typically the seperate test mentioned, and it appears that Terry includes it in his analysis. In addition sludge and varnish seems like it's hard to measure as it's obviously cumulative as well as inside the engine. An assessment of existing sludge or varnish seems to require adding something to the oil and then either monitoring filter debris, or using an appropriate test of the now dissolved sludge and varnish, whatever the specific additive requires.

 

[JohnBrowning]

It all depends on how clean you want your engine and what type of engine you have! Engines with low power desitys that run rather cool are not going to be as prone to varnish! In the 1980to early 1990's it was easy to keep sludge and varnish at bay! All you had to do was change your oil every 1800-3000 miles with any detergent oil and you would almost always be fine! In the late 1990's we started to see higher cylinder head temp's, more restrictive exhaust, more agressive egr functions, longer OEM oil change intervals etc... We also started to see more sludge and varnish! Now in the early 2000's we are seeing one car company after another have sludge issues first it was Toyota then Dodge, then Audi now Saab and the list keeps growing!

 

[Dominik]

Would aggressive quick flushes like Gunk or STP help with Varnish??
I just did a flush on 2.5 L Nissan engine with 78,000 km on it with clean 20W-50 oil and one litre Gunk; the oil that came out after only 6-8 min at 1500 rpms was totally black!
I suppose that this would have had dissolved some of the varnishas as well.
Seriously I think that the quick flushes are getting too harsh a treatment here, to a certain extent they seem to help keeping an engine clean.