Originally Posted By: jrmason
ATF is an excellent cleaner for situations like this. Drain enough oil to be able to add back about 1/5 of the oil capacity with ATF and start the engine and allow it to come up to temp via high idle. Shut the motor down and drain. It's like dumping a quart of highly refined detergent in your engine, and best of all it won't wipe out your bearings.
Because I don't want this thread to get locked, I'm just gonna pretend you didn't just say that. ATF is not a good engine cleaner. That myth has been busted already.
Originally Posted By: 1 FMF
i'm confused,
how did you know the engine has/had a sludge issue?
did you ever pull valve covers, or did you get dark oil from an oil change and assume sludge?
i don't get why people fall in love with these de-sludge chemicals especially on a v-8 where all you need to do is pull valve covers and manually clean with kerosene, diesel, gas, and a garden hose. use an air hose and blow down through all the oil drain ports to the crank case, then drain it out.
sludge doesn't accumulate in the pressure passageways between the oil pump and bearings, using a solvent in high quantity is only going to cause a wiped bearing from lack of lubrication.
what i really don't get is you said you're not worried about sludge breaking loose and clogging your oil pickup, or being surprised if it dies from doing a solvent flush, but you said no way your pulling the pan and creating a nightmare? i guess your definition of nightmare differs from mine.
what kind of oil pressure do you get?
Nothing to be confused about bro.
1. Yes, the engine was sludged pretty badly when I got it. I removed VC's and cleaned the snot out of it the best I could using a rag, brush, kerosene, carb cleaner, etc. I had to de-plug the PCV system. I also have run a few gallons of MMO through the engine for the past few years....typically running 20% MMO, but occasionally up to 40% using 20w50 as a base oil.
2.) I still find carbon flakes in my oil all the time. I still find carbon flakes on the valve train. I know there is old crusty carbon all over the inside the engine if I find it on the dipstick when I pull it and I find it on the rock arms when I remove the oil filler cap.
3.) Even after a fresh change, the oil is always COAL black in 500 miles.
Finally, I don't think there was a ton of thick gooey sludge in this engine. But a lot of old crusty carbon, for sure. Probably some sludge too, but not enough to kill this engine. I don't think a flush with kerosene and paint thinner was going to cause sludge to break loose and kill this engine. But if this engine died tomorrow, I wouldn't be surprised. Whether it dies of old age or my flush, who knows.
All I'm really saying is....I'm ready to throw a new crate motor in this truck when this one dies. So, this was a perfect candidate to do this type flush to. I have nothing to loose. If I harmed the engine, oh well. If it did nothing, no problem. If it cleaned the engine out, possibly unclogging an oil port or something....or derestricting the oil pick up screen...that's a bonus.
Hard to tell oil pressure. OEM gauge on dash is flakey. But it typically reads around 30 PSI according to that thing, but I don't really trust much.