using Diesel fuel as engine flush

paddle · 18-10-2006, 10:32 PM

as i mentioned in a previous post,to flush my I6 motor clean,I have done an oil change but because of previous oil, it has turned my new stuff black within a week (magnatec) Im also using pureone filter and magnetic sump plug.
Now...
Can I just use 5 litres of diesel fuel,drop oil,keep filter on,fill with 5 litres of diesel fuel,disconnect leads and crank for a minute then do another oil change with magnatec and a new pureone filter? what are your views

TwistedEL · 18-10-2006, 11:38 PM

Being an ex e-series boy myself I remembered this thread here

TwistedEL · 18-10-2006, 11:39 PM

Ask any of those guys if they actually did it

bodes-sh · 18-10-2006, 11:45 PM

damn that was pretty nasty looking...it's up to you i guess, if you want to give it a go then as you probably know it's at your own risk...

ronwest · 18-10-2006, 11:54 PM

I might be tempted to do use diesel in a crappy old motor that didn't matter much but you'd have to be careful that you didn't clean it TOO well.

Diesel is high in detergent and it may loosen and wash carbon from rings, for example.

Sounds good? Well the downside is that you may suffer a loss of compression.

How long would you like your oil to remain "non-black"? What does "black" oil mean?

If I was concerned about my oil getting "black" too quickly I'd get it analysed so I actually knew the source and level of contamination.

If it were my current car and I wanted to "clean" the engine I might use an engine flushing oil but I would more likely just change the oil more often.

str02 · 19-10-2006, 08:34 AM

Anyone tried Marvel Mystery Oil? Popular in aero engines and in some motorcycle circles. I have used it in motorcycle engines to clean up clutch plates (wet clutch in mosy bikes)

Rollin · 19-10-2006, 08:01 PM

Far out...whoever thought of the "diesel fuel to flush the engine" idea should be bloody shot.

I've an idea..change the oil and filter more than once a century!

Do oil and filter using the products of your choice every 5000km and you won't have a problem.

If you INSIST on messing about with it, use diesel OIL.

Diesel OIL is high in detergents, so you could fill with diesel engine oil and fresh filter, drive for 1000km, change oil and filter, then another 1000km, and then change oil and filter, using whatever oil you want.

Diesel is primarily a FUEL, and secondly a LUBRICANT, it is not a DETERGENT or an ENGINE FLUSH.

stiddy · 19-10-2006, 08:48 PM

ive mixed diesel with engine oil before as an engine flush so to speak, let it run for a couple of mins and then droped it all, ran it on normal oil for a day, then dropped that and put in good oil, and black oil never came out of that motor ever again in 2 years of owning it, also never had a single engine problem.

Ruger · 19-10-2006, 10:40 PM

a safer way of doing it is leaving the pan bolt out and just pouring the diesel through the motor DO NOT start the motor on the diesel and definately dont drive it! if your worried about metal bits and shards in your motor (why would you?) then if you have a steel pan stick a magnet at the bottom of the sump. very common.

PHATXR8 · 19-10-2006, 11:04 PM

I agree with Rollin

I know of a mechanic who used to use Shell Rimula X for cleaning old petrol engines. I had a look at the Shell website and it would appear that they don't call it Rimula X anymore - its' now Shell Helix Diesel.

This guy swore that it would clean even the dirtiest petrol engines with just one oil change.

ronwest · 20-10-2006, 01:12 AM

Quote:

Originally Posted by PHATXR8

I agree with Rollin

I know of a mechanic who used to use Shell Rimula X for cleaning old petrol engines. I had a look at the Shell website and it would appear that they don't call it Rimula X anymore - its' now Shell Helix Diesel.

This guy swore that it would clean even the dirtiest petrol engines with just one oil change.

Yes, well I seem to have missed the op's ref to diesel *fuel* as an engine cleaner and then confused fuel and oil in my reply. Apart from that it was spot on, lol.
In my defense I'll add that diesel fuel does have a detergent component and it is actually commonly used in diesel *fuel* additives packages ;)

BUT about diesel *oil*...

My family had 20 or so semi-trailers back in the mid 60's to early 80's. I forget the year but somewhere around the middle to late 70's Shell brought out a diesel oil called "Rotella".

It was supposed to be the bees knees for diesel engines as it had a very high detergent component. The downside of a very high detergent component became apparent after 8 or so engine rebuilds at around (at the time) $6000 each.
That episode was also the catalyst for an oil analysis program for all the trucks oils (engine, gearbox, diffs). It cost a bit to set up but saved many, many dollars by picking up component failures early and also extending the oil change intervals. I'm a big fan of oil analysis.

As far as diesel *oil* is concerned, I would be very wary about using it as an engine flush.

There are flushing oils available for that purpose so I'm not sure why anyone would take a chance on anything other than an old "so what" motor?