Diesel flush before oil change: Fact or fiction?

[Crunch]

Last year I read several posts from people who said they flushed their engine with diesel fuel before doing the oil change. I thought they were joking, but now I wonder. Who's really doing this? If it's not an urban legend, what is the process, and are there any drawbacks or risks?

 

[ttreibel]

Maybe on an old neglected diesel that has missed a dozen oil changes and then I would use Marvs Mystery Oil or Berrymans B-12 and not diesel oil. I would never do it on a new Cummins. You don't want to dump ATF in the fuel either thats another old timer treatment or fill the fuel filter up with ATF at a change. However I am a firm believer in fuel additives like Stanadyne.

 

[nickleinonen]

i've done it before, but won't do it to a good engine. on a beater enginer, pour in a few liters of good ol #2 and run it for a while [idle, light loads -watch that lube oil pressure gauge] get it nice and warm, then dump, fill with cheap cheap oil, run for a week , then dump again and run regular oil. it will clean out a lot of stuff out of the lube system and take a good bit of carbon with it

 

[y-knot]

Not sure which brand of oil you plan to switch too? But Amsoil does make and recomend you use their engine flush before you switch over to their synthectic oil if the engine is not new. It is very simple, read the directions and determin the amout needed, for most diesels it works out too about 1 to 1 1/2 quarts, drain that amount out of the crankcase, add the flush and run the engine for the time recomended. After that just drain the oil and install the new synthetic oil with new filter and top off. The flush is suppose to remove build up, deposits and most other un-wanted rimnances from the conventional oil use and or the lack of maintanence. It is a one time opperation that asures your engine will be clean and enjoy all the benifits of synthetic oil use.

 

[mhenon]

Engine flush

You can buy a product called "motor flush" (or something like that) at Wmart... but it's mostly diesel fuel.

I flush the engine once in awhile. like it was said above... dump a quart of diesel fuel in your oil, while it's hot, and run it for 5 minutes. It will come out "real" black. Then change your oil and filter as usual and the insides should be squeeky clean.

I use to follow that proceedure with another flush of straight diesel fuel to really clean things out (on my gasser's). Never had any problems doing it but don't think it's a good idea anymore. I certainly wouldn't do that with the Cummins. I guess we all tried a lot of crazy stuff when we were younger.

The only time I would be concerned about flushing the engine is if it were a high mileage vehicle and possible very dirty (inside). Too much crude might break loose and who knows what kind of stuff would get plugged up. Since I do my truck on a regular basis... I don't worry about it.



Mike

 

[ttreibel]

Running any synthetic oil will clean out a dirty engine. If I was to switch to synthetic on an older engine I would run mobile 1 for a month in the winter like 10-30 weight then dump and put in Amsoil if thats what you want. You don't want diesel in the system you can't drain it all out. If I was leaving something behind I would rather have it be a synthetic.

 

[Badunit]

There are (or were) a lot of 6. 0 Powerstroke owners doing this. Unfortunately for them, they aren't doing it on purpose; leaking injectors are doing it for them.

 

[bmoeller]

I wouldn't run diesel in the lube oil. Hydrotex ( http://lubesolutions.com/html/home_lube.html ) makes an additive for the lube oil.



My uncle has used it for many years with great results. One example, he had bought a used Massey-Ferguson 860 combine. The had to do some engine work on it. He said it was very dirty under the valve covers. After working on it, the didn't cleant he under-sides of the covers before installing them. Instead, they put in the additive as a test. They pulled the covers after harvest, and it had cleaned them right up.

 

[Vaughn MacKenzie]

On the last oil change I put synthetic in my '96 I bought recently, which had only dino until now. It lived on a diet of Delo 400. I thought after running 352,000 miles on dino the synthetic would turn black immediately, but not at all. I didn't use an engine flush, I thought I'd let the synthetic do the cleaning. I am changing the oil filter before 1000 miles anyway. The oil is starting to change color on the dipstick after 900 miles but nothing like the coal black I expected.



I have a crusty 6. 2L in a '84 Blazer I'm using to beat around in and 4x4 with/winter rig. I might try the diesel flush trick on that thing, LOL



Vaughn