I have a knocking in my motor and it was mentioned that before I tear the uppper end down, that I try a ATF Transmission flush in the engine. Bring motor to operating temp and then drain.
Something about cleansing the motor and removing lifter and rocker arm knock. Wondering if anyone has heard of this. The knock sounds like something in the rocker arms.

 

Did this in old car engines, would actually replaced the filter, add 1 quart of ATF, drive for about an hour and then drain it. You could see the sludge that was coming out of it. If I was dis-satisfied with the results, change the filter, add 1 more quart of ATF and fill with motor oil and drive until the next scheduled oil change. I don't know if I would add a whole quart to a motorcycle engine.

 

Sounds too good to be true. Wish it were that easy to get rid of a knock.Never heard of doing that but I guess it wouldn't hurt.

 

I have done a similar flush do to carbon knocks on oldsmobile engines in the mid 1970's that really had so much carbon in them that it sounded like a rod knock.GM made a product called top end flush and I would fog the engine thru the carb and let it sit and soak after I flooded it with the product,then pull the plugs,clean them,restart te engine and the knock was gone,however it produces so much exhaust smoke that it would look like a huge fire.I would not think that a HD would ever have a carbon knock as we uaually do not operate them a low RPM's and slow sppeds.I would think that if you have a knock it is a part failure and try putting a stethiscope on the engine to find were the noise is comming from and go from there.

 

If i were to do something like this i would use marvel mystery oil to flush the engine.Marvel will do the job if your engine knocking is indeed sludge related, it cleans up lifters very well.These modern day oils though do not sludge up much at all if you change it on a regular basis.I recently sold my jeep with 318k miles on it.Pulled the oil pan at about 210k to fix the rear main seal and could not believe how clean the oil pan was, and the only oil i ever run in that straight 6 engine is regular valvoline 10w-30 in winter and straight 30w valvoline in summer.Never did a damn thing to the engine in 318k miles,sold it to a fella at work and he drives it every day.

 

This thread is gonna bring a lot of comments.

Did that when the wife blew the head gasket on her Toyota, just did it on my F150 also just get some crap outta the motor. It works. Don't think it will cure the knock though. I would use the stethoscope method to try and narrow it down too.

And for gawds sake if you do that don't forget to change the oil filter.

 

I have done it, and it cleared up a lifter tapping. Tranny fluid is must 10 weight motor oil, basically. I put 5 quarts in my truck, drove the hell out of it for one day, then changed oil and filter. The high detergents and conditioners can do wonders. If it is a bearing knock, of course it won't fix that. Try it , it will not hurt a thing.

 

While flushing motors has been around for years, it's typically done on vehicles where the oil is stored in, and drained from the crankcase pan which means the flush mix gets completely drained when you drain the oil.

In a dry sump motor like your Harley, not all of the oil is drained from the motor/oil system when you do a regular oil change. Some of that "diluted" flush mixture will remain in the system unless you use a purge device.

IMO, if your running a good quality synthetic oil, there should be no reason to flush the system since sludge doesn't form to begin with.

 

but what about my 99 that has had nothing but regular oil in it since birth. How do I flush that motor? Would marvels mystery oil be a better alternative to ATF?

 

It is 6 of one and a half dozen of the other.
I preferred to use ATF because of the high detergent percentage in it. In todays world it is not as necessary as it would of been say 10 years ago. Modern oils are far more advanced now, exspecailly since the synthetics entered the market.