Diesel/ Kerosene flush M50 engine [Archive] - Bimmerfest - BMW Forums

: Diesel/ Kerosene flush M50 engine

11-07-2009, 04:06 PM
Hi everyone,

Is there any danger in using 1-2 quarts of diesel to flush the engine at my next scheduled oil change?

The diesel is purchased from a petrol station, and then poured into the crankcase. The engine is then run at idle for about 20 minutes.

I've done this before on an E30's engine. The engine ran better but then after doing this twice I began to notice white smoke coming out of the tailpipe. Now, it was a really old engine so it could be normal wear and tear but i don't know if the diesel flush procedure listed above contributed to this.

I understand that this can also be done with kerosene instead of diesel.

Anybody done this before? Please advise thanks !


Ryan M
11-07-2009, 04:21 PM
I've heard of it done, but never actually done it myself.

11-08-2009, 03:54 PM
seems a bit harsh to me. Google for Auto-rx. It can clean sludge genlty over time. I did it on my car and seemed to help with performace and smoothness.

11-08-2009, 04:16 PM
I have noticed that engine flush treatments smell strikingly like desel fule. Hmmm. LOL... Should be OK but use no more than one quart. Or just be on the safe side and get a can of engine flush from an autopart store.

11-09-2009, 08:16 AM
Diesel and kerosene are both poor lubricants but fair solvents.
what you are suggesting is an old time way to flush out accumulated sludge before there were decent detergent oils also when you could overhaul an engine for a couple hundred bucks if you F'ed it up.
If you engine is dirty then I suggest you do several short interval oil and filter changes. Tear apart the filters and watch for the crap to diminish. Quality oil will dissolve the sludge over time and still lubricate your engine.

11-23-2009, 05:10 PM
Hi Everyone,

Sorry for the late response, I was out of town a fair bit recently. Last 2 weeks ago, I added 1 quart of ATF Dexron 2 to my crankcase and drove it to my mech's shop for an oil change. The engine immediately felt *much smoother* (the engine oil was semi synthetic). It was a 10 minute drive. The oil that came out was black enough to look like it was three times older than it actually was, according to my mech. After reading the posts here, I decided to do a fast oil change with cheap 20-50 dino oil after 3 full petrol tanks of driving or roughly after 1 month. That's in about 2 weeks. I'll be adding ATF fluid to the mix and then, at the mech's garage, I'll be adding half a quart of kerosene to the crank case, running it for 5 minutes, and then will take out all the oil and replace it wil 5-40w synthetic Carlube oil, together with a new filter. Will let you guys know how it goes. Thanks for the responses.

11-23-2009, 07:04 PM
Lot of people seem to like Marvel Mystery oil (MMO) in both oil and gas. Swears it cleans their engine and when used in the gas makes engine smoother and acts as an upper cylinder lube. It also smells like wintergreen!!! Who knows?

11-25-2009, 11:24 AM
If you want a quick and cheap method, right before your next oil change, put some ATF in the oil and drive 'spirited' for about 40-80 miles...then do oil flush/change. The detergents in ATF will help with sticky valve seals and just generally clean it up in there. Seafoam works great too, but I would never put diesel in...

attack eagle
12-06-2009, 04:45 AM
no need for kerosene anymore. used to be that you would fill it with kerosene and run it for 20 minutes at fast idle, but that was old nialheads, flat heads etc with poor/splash oiling.

you did atf once , you don't need to do it again. if you do, this is the last time fir at least 50k.

01-04-2010, 09:29 PM
Diesel and kerosene works but I think they can be a little harsh. But nothing I would worry about. Now marvel mystery oil isn't bad, but its not a quick fix just more of a preventative thing. 1/2 cup for the 4banger and 1 cup for the bigger engines of ATF running for 10-25 mins every oil change works great. Now stuff like Sea Foam works good but make sure you poor it after you air metering sensor/MAF they take those out fast. I am addicted to Amsoil engine flush myself but you maybe use it 1-2 times a year only, the rest of the time use the ATF. Hell I'm addicted to Amsoil everything lol.

01-05-2010, 08:33 AM
ATF running for 10-25 mins every oil change

Don't like your seals? The detergents in ATF will eat your gaskets and seals if you abuse it. I would watch the use of it.