I was speaking with a mechanic buddy last night and I was talking about flushing my s40 engine oil to get gunk out. He told me to replace my oil with transmission fluid, drive for 500 - 1000 KMs, then change the filter & replace with oil again. He is a mechanic, but I'm still a bit skeptical. Has anyone done or heard of this before. Can I screw up my engine?

 

Your post took me back to the late 1960's, early 1970's. Our local mechanic was a strong advocate of doing this. And, back then it probably made sense when there was little or no detergent in motor oil. Only, his method didn't involve driving on ATF, but simply allowing the motor to idle for 20 minutes or so, until it was thoroughly warmed up. Then letting it drain a long time, putting in some cheap oil, idling, and drain and refill with the "real" motor oil.

Now, with high detergent oils, I don't think this is a good idea. At least I haven't heard of anybody doing it in a very long time. Given the number of 150,000 plus mileage motors we read about here, unless there was a very specific problem, I'd say not to do it.

 

I wouldn't use atf.
I'd use desiel oil if you must.
google and "bob is the oil guy" forums will explain all.

 

I would never replace all the oil with ATF and drive that far. It's OK to replace a quart of oil with ATF and run it awhile, but not the distance you posted.

 

DO NOT DO THIS! You will damage your engine. ATF does not like being burnt in a combustion chamber and it just doesn't have teh viscosity to protect your engine, even idling. Driving it 1000kms with trans fluid would guarantee wiped bearings.
The correct way to flush a very badly gunked engine is to run a 50/50 mix of diesel fuel and a 10w/40 engine oil (mix before you add it to engine please) and only idle the engine for say 30 mins. For best results leave the engine sit a few hours after running the flush, then drain, refill with fresh oil and a new filter, run for 500km then dump oil and filter then normal oil fills.
If you only have a sticking lifter or similar, there are some very good add as you drive products to help, I use Nulon Lifter free and Tune, just put a bottle into our Magna the other day and it killed teh lifter noise almost immediately. The Magna has a 24 valve V6 and Mitsubishis are known for having very small, precise lifters that gunk up a lot, so it is a good testament to teh product.

Regards, Andrew.

 

I've read about using diesel fuel mix.
I wouldn't. But thats just me.
I still suggest having a look here ---> http://www.bobistheoilguy.com/
And also here ---> http://www.carbibles.com/engineoil_bible.html

 

I've done teh diesel many times without problems.

Regards, Andrew.

 

Thanks for the replies. Thought it sounded fishy - glad I didn't listen to him.

 

yeah right,,it would be dangerous to the engine…id rather add up quality egr valve to resolve such problem..

 

I kind of like to know where the mechanic works at.....

As long as you change oil & filter regularly, I do not believe you need to flush the engine on modern cars (fuel-injected, computer-controlled). You could also dump a bottle of Techron fuel system cleaner into the fuel tank at every/every other oil change to keep the induction mechanism (intake valves, etc...) clean.

If you insist on a squeaky clean motor, however, I suggest that you take the motor apart, scrub clean like crazy with dish-washing detergent of your wife (mom)'s recommendation.....

There are several different types of ATF and they are not interchangeable (there may be 1 or 2 that can be mixed but I would never do that myself).

Everyone else is correct.


JPN