What motor oil does the best job of cleaning?

[ka9mnx]

In a way, I'd prefer to take a slower and easier (on the engine) approach by using an oil that could help clean things up a bit. M1 0W-40 sounds like it may be an acceptable approach. The only downside is that I'd prefer a somewhat thinner oil, like a 5W-30 or 0W-30 in the sump. Is there another oil that would behave similarly to the M1 0W-40 in those thinner grades?

M1 HM 10w-30 should do it.

 

[LineArrayNut]

Suppose you had an engine with a bit of deposits in the top end and you wanted to use an oil that would help clean it up. Or maybe you bought a used car with unknown history and you wanted to clear out any crud that may have built up from missed maintenance.

Are some motor oils better for cleaning up an engine than others? If you suggest one, please give a reasoning as to why it cleans well.

Valvoline premium blue restore is stated specifically to clean rings, presumably it would clean other areas, top end included.

 

[john757]

20 years ago I bought a 1989 bronco with 169k on the speedo. I lived in Nashville and worked in NJ. I filled it up with Mobil one and headed to NJ.About half way to NJ the oil gauge started fluctuating so I stopped several times and started again with no improvement . I called my mechanic back in TN and he knew that I used Mobil one. He said to go to a service station, (back when there was such a thing) and get a thin oil in the motor and that should get me to NJ. He said the problem was the motor was old and fairly high mileage and the pickup tube in the pan was stopped up with crud the Mobil one had loosened. It worked and when I got to destination I changed the oil 4 more times, then filled with Mobil one and all was good. There’s my proof Mobil one is a pretty good cleaner.

 

[BlakeB]

BG Dynamic Engine Cleaner
There are a multitude of videos on YouTube demonstrating the cleaning ability of this stuff. It’s fairly expensive but appears to be very effective at cleaning an engine up quickly.


Before and after @ about 8:30

 

[dubber09]

Oils meant for diesel engines clean very well.

 

[RaRa]

Easily available in most stores will mobil 1 or vavoline restore 10w30 best . I will M1 2 oil change then used pennzoil ultra .