.

 

I've used it many times in the last 20 years. It'll do in 30 minutes what it takes ATF to do over an entire oil change.

I don't know what exactly is in it, but I know it is a solvent base with detergent and dispersive additives.

 

.

 

Judge it by the condition of the engine involved. You can get a pretty good idea looking under the fill cap of most engines.

AMSOIL just recommends running the flush and switching over. What I typically do when switching over to synthetic is put in fresh petroleum oil minus 1 quart, add a pint of flush, and use a new filter. Run it for 30 minutes, drain and fill with synthetic & new filter. Then, run the flush again at half the normal drain interval, change oil & filter again. Then go to normal drain intervals.

An alternate method (which AMSOIL recommended before they came out with the flush) is at your normal oil change, replace 1 quart of petroleum with a quart of synthetic. Run it for 3000 miles (or your normal drain interval), then change again only replace 2 quarts with synthetic, & so on until the entire fill is synthetic. This is a slower cleaning process if that makes you more comfortable.

In the 20 years I've been using it, I've seen one engine that had a sludge problem. My dad rescued a car from the junk yard; it had been in a trailer park flood, so that should give you a couple of ideas of its history. We did the flush thing, and about 4 months later, the sludge clogged the pump pick-up screen. But, that was an 80's car that had been severely neglected and abused. Had we run the flush again and drained the oil sooner, it probably wouldn't have had a problem. It's also possible that even without the flush, the screen would have clogged because we simply changed the oil.

I've had several pretty deposited-up engines that did not have any problem after using the flush.

 

Not many people around here besides 57 and I who use flush, most are scared from the 1 out of a thousand chance an engine may sludge up. Ive personally never had a problem with flush and Ive used it on Penzoil engines with 3 inches of gunk in the lifter valley with no ill effects. I would suggest what 57 reccomended flush it twice, if your weary flush it again @ 1500 miles and again before you switch to full synthetic. I think theres more of a possibility for engine damage not flushing the engine but thats just me.

 

Oh. You've found out how "good" Pennzoil is, too? It's almost like it has a natural tendency to turn back to crude oil in the crankcase. Maybe we should be re-selling that to the middle east?