Best way to remove varnish?

[IllinoisSparky]

Doing some work on my old 99 MB CLK320 that I bought in November, I had to remove the valve covers. I was really [censored] when I found all of the varnish in the pictures below.
It was so thick in spots that the vent (about 1/8") holes on both sides were COMPLETELY blocked. So oil vapors were not being burned in combustion.
Obviously PO didn't use proper MB spec oil/filter/or OCI. (my old 92 looks like new inside the valve cover)

So, I bought some engine flush, ran it through once on the current fill. Put some cheap oil, new filter, and flush in for 5 minute flush. Second flush oil only had 5 MINUTES run time, but came out black.(Pic of 5-minute old oil bottom)
Changed filter again and put in MB 229.5 approved oil.
Gonna leave it in for a while, then use an engine flush again.

So, do you think that is a good cure? Not aggressive enough? Too aggressive?

BTW, it had some valve "ticking" before, especially at startup, but the valves were audibly quieter as the 5 minute flush went on!

 

[CT8]

It is really not worth worrying about . Run a synthetic and see what the syn does to the varnish.

 

[Popsy]

I'd consider short oci for some times, maybe another engine flush before next OC, but be sure there's no sludge before.

Varnish looks very thick, like pre-sludge, lol.

Maybe another oil like Rotella T6 would clean better than LiquiMoly?
This brand is not highly regarded around here, but I never tried it so can't comment on its cleaning abilities.

 

[Ducked]

Delvac MX 15W40 or equivalent, (like Rotella above).

Flushate doesn't look too bad to me.

 

[spasm3]

Kreen really cleaned my saturn engine.

 

[4D-56]

Kreen

 

[expat]

Auto Rx........ Just kidding

 

[ac_tc]

Add a quart or two of redline if you doesent like to use hdeo.
- i would use hdeo.

 

[weasley]

If that is genuinely varnish (a hard, lacquer-like layer) rather than a soft sludge precursor then you won't remove it by changing oil types or flushing.

What does the underside of the valve cover look like?

 

[UltrafanUK]

Originally Posted By: weasley
If that is genuinely varnish (a hard, lacquer-like layer) rather than a soft sludge precursor then you won't remove it by changing oil types or flushing.

What does the underside of the valve cover look like?


Short OCI's don't remove varnish too well, but a good quality idle use flush will shift any oil related deposit, including baked on varnish. It might well need 2 goes to get it all off.

Although most varnish deposits are caused by too long an OCI or oils that lack enough detergents, they can be caused by overheating.

 

[Kamele0N]

1-2 dcl of diesel into oil....short trip...and then OCI!

 

[IllinoisSparky]

If it wasn't such a hassle to post pics on this site, I would show you.

Underside had lighter varnish, and some small chunks. Not sure if the varnish doesn't stick as well to magnesium valve cover.
It was a hard varnish finish. Couldn't hardly scrub it off with a rag.
Did two flushes. Second one the oil was only in for 5 minutes and came out black.

 

[IllinoisSparky]

Originally Posted By: CT8
It is really not worth worrying about . Run a synthetic and see what the syn does to the varnish.

I think the first OC I did after buying it had already done some varnish removal. It was Mobil 1 Euro 0w40.
I will shorten the OCI to around 3-4k miles, and do a flush each time. After about 5 years, it should be pretty clean!

Not as concerned about the varnish on non-moving parts, as I am about the blocked ports, noisy valves, etc. Valves are MUCH quieter now (I could actually hear the sound level go down as the flush was happening), vacuum ports are open again to remove oil vapors, so I think I will quit worrying so much....

Thanks.

 

[IllinoisSparky]

Originally Posted By: Popsy
I'd consider short oci for some times, maybe another engine flush before next OC, but be sure there's no sludge before.

Varnish looks very thick, like pre-sludge, lol.

Maybe another oil like Rotella T6 would clean better than LiquiMoly?
This brand is not highly regarded around here, but I never tried it so can't comment on its cleaning abilities.


Varnish was hard. Not much sludge. Some little chunks in a few spots.
I think I will do a flush before the next several shorter OCI's, just for piece of mind. Now that I have the vacuum ports open, and valves quieter, I want to keep it that way!

Just used the LM because I had it in my stash, and it meets MB 229.5 spec. Went to Walmart for Mobil 1 Euro 0W-40, but they were out - except for quart bottles for $9 each. Not gonna pay $45 for 5 quarts!

 

[IllinoisSparky]

Originally Posted By: Ducked
Delvac MX 15W40 or equivalent, (like Rotella above).

Flushate doesn't look too bad to me.


Delvac and Rotella would probably work, but I am a "by-the-book" sorta guy, and they are not on the list of MB 229.5 approved oils. Heck, I was even nervous using non-spec oil for the 5 minute second flush!

I picked up the Gunk motor flush, and it cleaned quite a bit, since the new oil for the second flush was black in 5 minutes.

Thanks

 

[chrisri]

Originally Posted By: IllinoisSparky
Originally Posted By: Ducked
Delvac MX 15W40 or equivalent, (like Rotella above).

Flushate doesn't look too bad to me.


Delvac and Rotella would probably work, but I am a "by-the-book" sorta guy, and they are not on the list of MB 229.5 approved oils. Heck, I was even nervous using non-spec oil for the 5 minute second flush!

I picked up the Gunk motor flush, and it cleaned quite a bit, since the new oil for the second flush was black in 5 minutes.

Thanks

Stick with approved oils, there's zero reason to think HDEO will clean anything better than A3/B4 oil with 229.5 specification. Varnish in petrol engines is different to diesels which usually have some diesel in sump.

 

[Oro_O]

Originally Posted By: Kamele0N
1-2 dcl of diesel into oil....short trip...and then OCI!


Good answer. I prefer the older MB factory method - replace 1 to 2 qts of a new clean fill with Kerosene (or diesel if unavailable), and idle for 15 minutes, no driving. Let cool, repeat. Dump the oil and repeat the process if needed. I don't like loading the engine with the oil thinned any appreciable amount.

I have used that method with very good results on two occasions.

 

[Pontual]

To remove varnish, it is necessary above normal operation engine oil temperature. Like some say: "heat is you friend there". You have this in summer operation, traffic jams and so... You could let the engine running for more than 5 hours too...

 

[IllinoisSparky]

Originally Posted By: chrisri
Originally Posted By: IllinoisSparky
Originally Posted By: Ducked
Delvac MX 15W40 or equivalent, (like Rotella above).

Flushate doesn't look too bad to me.


Delvac and Rotella would probably work, but I am a "by-the-book" sorta guy, and they are not on the list of MB 229.5 approved oils. Heck, I was even nervous using non-spec oil for the 5 minute second flush!

I picked up the Gunk motor flush, and it cleaned quite a bit, since the new oil for the second flush was black in 5 minutes.


Thanks

Stick with approved oils, there's zero reason to think HDEO will clean anything better than A3/B4 oil with 229.5 specification. Varnish in petrol engines is different to diesels which usually have some diesel in sump.


I agree Chris.

 

[IllinoisSparky]

Originally Posted By: Pontual
To remove varnish, it is necessary above normal operation engine oil temperature. Like some say: "heat is you friend there". You have this in summer operation, traffic jams and so... You could let the engine running for more than 5 hours too...


Pontual - planning to drive it hard with the clean oil soon!