[Vwdiesel] cleaning carbon clogged rings without disassembly

[Val Christian]

> Runaway aside, you can just run the engine with a synthetic and a
> "sticky ring" additive. I'll bet that if you run the engine hot and long
> enough, things will loosen up on their own. But letting it sit for a
> while with a good solvent in the cylinders would be a good start. Just
> make sure you clear out any of this volatile liquid before starting.
> 
> -Gary

Kinda like spraying in carb cleaner for a couple of weeks, turning the 
engine a bit every couple of hours, eh?

I doubt it will work in this case, but I have found that running higher 
detergent oils, in a light weight form (20W, or perhaps 5W-30), helps
free up rings a little.  Without high torque usage, not using a heavy oil
won't really be a factor on the engine.

I've also learned that running 20W-50 oil, as I used to always do in 
my Rabbits, is not exactly the best thing to keep the ring area cleaned out.

One aircraft engine I just saw torn down, has lived for over 30 years and
2200 hours (that's right, no top over haul?!?).  One owner, and for 
some reason, he always used 65 grade av oil.  Not exactly what the book
says, but he argued that after takeoff, he was flying where it was 
cold, so he would use the oil grade for where the most time was put
on the engine.  The reason I mention this is because his pistons looked
almost new in the ring lands.  There was a less than usual scuffing 
on the pistons, and two of the wrist pins were worn on the ends.
But the lands were very clean.

I jsut put in a call to a chemist, to see if he has any suggestions on 
the ring carbonization.  Sticky rings have been an issue with VW diesels,
especially when they get high time.

Val