Using Diesel as an engine flush???

[MR.BA.GT.332]

talkin to some old timers at work and one suggested he used to put some diesel in his oil before doing a service to "give 'er a good cleanout"

doing this really a good idea? ive used diesel to clean stuff down and clean parts in etc but this i think seemed a little left field so, thought id drop the question....

That's what you pay $12 for 500ml for when you buy a Wynns or Nulon Engine flush.

It thins the oil and is perfectly fine to use.

A better version of an engine flush is to drain your oil. Fill it up with a cheapie oil of the same viscosity and one which meets the basic recommendations for your car. Run that through for a day or two and drain it.

When you consider people do it to their cooling systems with water, it makes sense to do it to your car. It will really clean it out and you can get supermarket oil for about $10-15.

Otherwise you're just dropping the oil in the pan pretty much. Have you heard the arguments against using transmission oil sump plugs? Well apply that to the more important engine, you want to clean out more than just the pan.

[PoMmYwOG]

yeah it works a treat just dont rev it too hard when circulating the diesel as it thins the oil big time. I usually just let it idle for about 10 mins or go for a couple laps aroudn the block at under 2 grand.

Just becareful with it if u have got a sludgy engine as it may loosen it and block the oil pick up...not healthy!

[Hunter]

I've heard old mechs talk about this too. But be careful, if the engine is old and worn, cleaning it out could actually result in the engine blowing oil smoke very shortly - apparently oil sludge and varnish get to the point where they help the rings seal properly etc and when you clean an old worn engine out, engine no longer seals so well and blows smoke.

[da_ilks]

Haha, agree with the above in certain circumstances! My old 308 had noisy tappets, so I bought some tappet cleaner which was meant to quieten them down. All it did was release the gunk and made them 3x noiser :/

[The Yeti]

Originally Posted by Hunter

I've heard old mechs talk about this too. But be careful, if the engine is old and worn, cleaning it out could actually result in the engine blowing oil smoke very shortly - apparently oil sludge and varnish get to the point where they help the rings seal properly etc and when you clean an old worn engine out, engine no longer seals so well and blows smoke.

Yes this can happen Ive had it happen, then you jsut wack chemiseal in the pots to stop it smoking again:

hmmm perhaps not

[kempster1]

Originally Posted by Shounak

A better version of an engine flush is to drain your oil. Fill it up with a cheapie oil of the same viscosity and one which meets the basic recommendations for your car. Run that through for a day or two and drain it.

When you consider people do it to their cooling systems with water, it makes sense to do it to your car. It will really clean it out and you can get supermarket oil for about $10-15.

This is the only way to do a flush, diesel in the oil system will damage bearings.

[ea90gl]

Have to agree with the above, repeat oil change is the best way to go. Strange thing happened to the work hack, the motor had a big end knock sound so there I am thinking motors on the way out, then thought why not do a couple of oil changes using the budget stuff (correct visocsity), after the second oil drop the sound dissapeared never to return again and that was a while ago. Also remember how "like dissolves like" so if your mixing old and new oil they should gel real well and eventually the old grime and gunk will pass through each oil change, sort of like diluting cordial - you get to the point where its just like water

[krt10]

i know of people doing the same thing but with fuel injector cleaner. same principal i suppose.

[snakeoil]

I've heard old mechs talk about this too. But be careful, if the engine is old and worn, cleaning it out could actually result in the engine blowing oil smoke very shortly - apparently oil sludge and varnish get to the point where they help the rings seal properly etc and when you clean an old worn engine out, engine no longer seals so well and blows smoke.

That's what you pay $12 for 500ml for when you buy a Wynns or Nulon Engine flush.What for kerosene??? and they have just made $12

This is the only way to do a flush, diesel in the oil system will damage bearings
Dude absoulutely dead right
MR 460 big block go to oil analysis which will freak most poorly trained mechanics out and then you know for sure what it going on.Diesel mechanics do this every day of the week
Cheers

[old-jim]

I have heard that the best way to flush an engine is with a couple of oil changes. But when you first change the old oil, use oil that is formulated for diesel engines. It has a high detergent content that will loosen all the old gunk.
Run this for 500km and then do a proper oil change.
Change the filter for both oil changes.

But you can block up oil galleries, clog pickups and finish with noisy tappets.
No great loss I suppose if the engine is that far gone.

cheers - old jim