In Reply to: ENGINE FLUSHIN QUESTION.... posted by Dario on January 26, 2002 at 21:48:18:
I normally warm the engine at idle for 10 minutes before changing the oil & filter. Gunk seemed to go hand-in-hand with my changing habbits.
My BMW mechanic told me later not to trust it. The solvents may disrupt the lubrication properties at the critical surfaces -- if only for a few seconds. Like pouring a qt of gas in your block.
If cleaning the internals is what I wanted, he recommended Risolone instead. "Stuff's been around for a long time and it works great" he says. Just follow the directions on the bottle - 1 qt every oil change.
The next time I adjusted my valves it was very noticable - no colored varnish. Never had a problem with sludge so I can't compare there.