use of flushing oils

[oonitrat]

i would like to know how can i clean the engine sludge at the time of conducting the engine oil change . i have heard that if diesel is poured in to the engine and kept starting for couple of minutes it will clean / flush the engine from inside is it the correct way.


oonitrat

[fredjacksonsan]

www.auto-rx.com worked great for me. You can read a lot about it on www.bobistheoilguy.com

[MagicRat]

Originally Posted by oonitrat

i would like to know how can i clean the engine sludge at the time of conducting the engine oil change . i have heard that if diesel is poured in to the engine and kept starting for couple of minutes it will clean / flush the engine from inside is it the correct way.

This has worked for me, as follows.
Drain all the engine oil and change the filter.

Add 5 quarts of diesel to the crankcase.

Remove all the spark plugs and crank the engine for about 10 seconds. Let it sit for an hour and crank another 10 sec. Follow this interval all day, then drain the diesel and change the oil filter.

Add 5 quarts of clean engine oil, then spin the engine for 10 seconds.

Put the plugs back in and run the engine for 2 minutes at idle, with no load. Than change the oil and fliter again.

[curtis73]

I've never torn down an engine after a flush, but I've never had any ill effects from just buying a motor flush product and following the directions. Usually it says to add it to the oil, run for 5 minutes (not drive) and then drain and refill.

Those aftermarket products are probably just diesel that costs $5 a quart, but I feel a touch better using a product that I can sue if my engine blows up.

[mazdatech177]

please dont use this engine flush crap... if you really have a sludge problem, drop your oil pan, clean the pan and strainer as best as possible and reassemble. and if you cant afford to have that done then just wait till you buy your next car and change the oil at recommended intervals

[curtis73]

Its not just an oil pan thing. The lifter valley, heads, and passageways get an acidic sludge buildup that starts causing lifter bleed, pH problems, and can start restricting flow in the smaller orifices. That can't be cured without every single part going through the hot tank and some solvent on a bottle brush, but in the meantime it helps to flush.

We could debate on harm vs. help of the flush products but they've never bitten me. Think of it like your Kool-ade pitcher in the fridge. If you keep using koolade and making more without washing the pitcher, it starts getting funky and red. Even if you change the oil at recommended intervals, the sludge still builds up. Ya gotta put it through the dishwasher from time to time.... The pitcher, that is.

[TheSilentChamber]

Obviously you've never ate kool-aid sludge thats been five years in the making.

[mazdatech177]

i routinely tear down engines with well over 100k miles on them and have seen plenty with no sludge buildup at all. but these were well maintaned from day one

[cody_e]

Originally Posted by curtis73

Even if you change the oil at recommended intervals, the sludge still builds up. Ya gotta put it through the dishwasher from time to time.... The pitcher, that is.

I thought oil had detergents in it to keep sludge to a minimum.

[curtis73]

Yes there are detergents, but they aren't perfect. Mazdatech... have you ever torn one down without a brown coating on some internal parts? That's what we're talking about. That staining sludge is basically carbon from burnt oil. It sticks to stuff, and in a low-flow area it can be deadly. If it clogs up an internal passage its not a good thing.

You're right... its not usually "sludge" like the milkshake you find in a car with a bad PCV valve, its all the junk that doesn't get dissolved by the new oil. The flush is designed to get all the black caked on coating off of stuff in there; piston skirts, pins, oil passages, etc.

[alfonso2501]

Originally Posted by fredjacksonsan

www.auto-rx.com worked great for me...

oonitrat, how do you know that you got sludge buildup?