LC20 and varnish removal

[boy412]

My first post here. I DID search before posting!

I received a few bottles of LC20 today and wanted to know how much I should use to remove some varnish that has built up over 200,000 miles in my '03 Audi A4 (1.8T motor). I read a post on here a while back that advocated running 16oz of LC20 for the duration of the OCI. Is there any harm in running this amount of additive?

AutoRX treatments are about the same amount of fluid (two bottles into the crankcase for a "sludge treatment"), which I will probably also do after the LC20 has been in the engine for 3-4k. My understanding is the LC20 will get the varnish removal process started a bit quicker and then the AutoRX will take over from there. This sounds like a reasonable approach and appeals to me more than some of these other (stronger/aggressive) engine cleaners on the market.

Any thoughts or input from others who have used LC20 (either by itself or in conjunction with AutoRX)?

 

[CT8]

People on the board seem to think A RX is a waste of $$

 

[simple_gifts]

Is the varnish on a working surface? If not, not much to worry about. I've run 16oz in a 6qt sump of 5w-40 in a ford I6

 

[HerrStig]

Originally Posted By: CT8
People on the board seem to think A RX is a waste of $$
But.....there's a devotee born every minute. How abou just a really good cleaning oil?

 

[L_Sludger]

Let's party like its 2002!

 

[boy412]

I run a good quality oil in the motor but my shop was concerned about some varnish visible through the oil cap hole.

About 1.5 years ago there was some drama caused by low oil pressure (clogged pickup tube and a decent amount of sludge) and now I'm just extra careful about this kind of thing. I am getting a little lifter noise too so I figured there might be some residual sludge to contend with. Hence my interest in LC20 and AutoRX.

Thanks simple_gifts...the one person who actually had something relevant to post.

 

[MolaKule]

As simple-gifts said surface varnish is not much of big deal.

Varnish is mostly just a sticky film of oil and fuel vapors that condensed on a cooler surface.

I would only run LCD20 or any chemical like this for about 500 miles at the most and then change oil and filter.

I have poured LCD20 on a hot engine head and removed varnish and sludge with a stiff nylon brush.

As long as the varnish is not retarding the motion of moving parts, it is not much of a concern.

Now in hydraulic systems, varnish is a major concern.

 

[Crashbox]

For what it's worth, I've used LC20 for about nine years in my 1995 Civic but never more than two oz./qt. as I read a while back that excessive amounts can 'de-polymerize' synthetic oils (but not so much with non-synthetics). If I were inclined to run almost four oz./qt. to speed the process up, then I would definitely change the oil/filter out at 500 miles per MolaKule's advice.

As for the Auto-RX which I have also used (and still have plenty left), I've never ran the two-bottle 'sludge' treatment method but it probably won't hurt IMO.

One thing that I DID discover after running LC20 for several years along with a couple of ARX treatments thrown in for good measure... I went almost 50K miles between the second and third ARX treatments, and the third treatment showed that there was practically nothing left to remove. The LC20 definitely helped keep things nice and shiny-bright (using synthetic oil didn't hurt, either).

These are just my observations with both products after long usage, your mileage may vary.