5W20 in place of 10W60 for cleaning

[bwco]

This might be a question that you guys have covered many times, but I'm looking for any input from personal experience that your engine is running fine.

My engine calls for 10W60 oil (2004 BMW E46 M3 engine)and it seems a bit sludged up for internal parts (dark stain seen from oil fill hole). If I'm "NOT" looking to do AutoRX nor engine flushing chemicals. But I'm looking to run some very light 5W20 or even 0W20 synthetic oil at idle for half an hour. Am I pushing the tolerence of the engine with low oil pressure and high engine temp?
I don't wanna blow up the engine just because of a light weight oil cleaning method.

Thanks for any input !

 

[Falcon_LS]

You've got two safe options IMO. One is to replace 25% of your slump capacity with MMO and drive as normal, and the second is Auto-Rx. A lighter weight oil would not do much cleaning.

Also, what 10W-60 are you using?

 

[chevrofreak]

Why do you not want to do Auto RX?

What makes you think only half an hour of a really thin oil would do the cleaning you want done?

 

[Eddie]

You said you were looking for personnel experience of which I have none. However: if the recommended oil is at 60wt, I would not drop to a 20wt. I too think AutoRX is a much safer and gentler way to go.

 

[sprintman]

RX is doing a fabulous job on my BMW (5W40), Your engine requires a cetain HTHS spec and you sure won't get it with 5W20. There sure are some strange posts on BITOG lately.

 

[d00df00d]

Originally Posted By: bwco
My engine calls for 10W60 oil (2004 BMW E46 M3 engine)and it seems a bit sludged up for internal parts (dark stain seen from oil fill hole).

First things first: are you absolutely positive that is sludge, and not varnish? Sludge is definitely something to worry about, but varnish is not.

Second, you can't really tell just by looking down the fill hole that your engine is sludged up. Do you have any other symptoms? Poor running, etc.? Have you taken the valve cover off?

Third, no oil is going to clean things up in 30 minutes, no matter what viscosity, even with additives. Any substance vicious enough to clean your engine's innards in that amount of time would probably do more harm than good in a running engine, and it would take quite a lot of time and oil to flush out before you could safely resume normal OCIs.

If you're really concerned, I would recommend running Motul 300V, RLI BioSyn, or maybe Red Line in a 40-weight or higher for a while. These are high ester oils with good cleaning properties over time. Change it at 3k or 4k mile intervals until the gunk dissolves, then switch back to factory oil and your normal OCI if you want.

There have been a few people who have used Motul 300V 5w-40 in S54s and been happy with it.

 

[bepperb]

Engines that run thin oil aren't magically clean, I guess I don't understand why a slightly thinner oil would help.

If it were mine, I'd probably try some shorter ocis, maybe 5000 miles, with M1 and see where that gets you. In the correct vis, of course.

FWIW, what you're describing sounds like varnish and isn't really a problem, but I can understand your concern on such a nice vehicle.

 

[demarpaint]

If you still have time before you change your oil then for the last 1000 miles of your OCI use a qt of MMO with the oil the engine calls for. Drain a qt of oil don't over fill it. I would run a full qt of MMO for the full OCI, especially during a Canadian winter. It will clean up your engine and start attacking the varnish.

 

[G-MAN]

Originally Posted By: bwco
I'm looking to run some very light 5W20 or even 0W20 synthetic oil at idle for half an hour.


All you're going to accomplish is wasting your time, and wasting some perfectly good 5w20 or 0w20 oil. No cleaning will take place.

 

[gregester]

here a nice article on additives....
http://www.math.uwaterloo.ca/~rblander/snake_oil.txt

 

[PT1]

Originally Posted By: G-MAN
Originally Posted By: bwco
I'm looking to run some very light 5W20 or even 0W20 synthetic oil at idle for half an hour.


All you're going to accomplish is wasting your time, and wasting some perfectly good 5w20 or 0w20 oil. No cleaning will take place.


+1 Exactly....unless you blow the engine with the 5w20...then your engine will be completely cleaned and seem new....

 

[bwco]

reasons of doing that is, I heard that 0W20 is a very good cleaning oil, just similar to people pouring thinner chemicals (ATF etc) to clean out thicker dirty oil. While keeping the engine lubricated and running, it's doing it cleaning at the same time.

I would like to clean the varnish or I may see baked sludges (slightly). I would not like to introduce any foreign chemicals except engine oil into the engine.

I'm using OEM bmw engine oil, which I think is Castrol TWS 10W60.

 

[demarpaint]

For a short (30 minutes) run the 0W20 won't hurt the engine. IIRC Dr. Haas is using it in an engine calling for a much "thicker" oil. I just don't see a 0W20 doing much if any cleaning for a 30 minute run. Since the engine is calling for a 10W60 oil I wouldn't be fooling around with a 0W20 oil. JMO

 

[Trajan]

I don't see a 0w20 doing anything in just 30 minutes. Outside of wasting time.

Sludge is like weight gain, doesn't happen overnight. Getting rid of either, without surgery, doesn't either.

 

[G-MAN]

Originally Posted By: bwco
reasons of doing that is, I heard that 0W20 is a very good cleaning oil, just similar to people pouring thinner chemicals (ATF etc) to clean out thicker dirty oil.


Total baloney on both counts.

If Castrol 10w60 is not removing your sludge or deposits, no oil will. Plus, if you've got sludge, or any deposits, with Castrol 10w60, then you need to shorten your OCIs.

 

[oliveoil]

Use Auto Rx to clean the internals. Use it at the end of one of your OCI's with 2K to go. Then do a good rinse cyle with either the BMW 10-60 (which is expensive) or a any dino 20-50 weight oil for 1.5 to 2K miles.know that the 10-60 sheers to a 40wt.

 

[chevrofreak]

Originally Posted By: bwco
I would like to clean the varnish or I may see baked sludges (slightly). I would not like to introduce any foreign chemicals except engine oil into the engine.


Auto RX isn't "chemicals". It is made of esters that are good at cleaning. It is perfectly safe for you to use.

 

[friendly_jacek]

Originally Posted By: gregester
here a nice article on additives....
http://www.math.uwaterloo.ca/~rblander/snake_oil.txt


Dated but good read. I myself fell pray to the Slick50 craze many, many years ago.

I agree that ARX is in a league of it's own and not a snake oil.

 

[coffee]

You could maybe try Mobil 1 HM 10w40 for an OCI and it would help clean anything out and it is a stout oil. Auto Rx is probably the best option with a good 10w60.

 

[JohnBrowning]

That isnot going to do anything at all! It would be different if it was a flushing oil like what was made and sold in Europe when I wasa young man. Not only was a 20Wt. but it was loaded wtih solvents,detergents and anti-wear ingredients. Regular 0W20 adn 5W20 is worthless for cleaning anything it is just regular oil their is nothing in it to clean!

I swear where do you people come up with these silly idea's? I mean I really want to hear the logic that leads one to believe that idling a car with a sump of 5W20 or 0W20 API approved oil is going to do to remove tough sludge from an engine? I mean what mechanism is supposed to do all this cleaning in regular oil? If regular oil had the ability to clean so well we would not have sludged up engines to start with would we? Baring a coolant leak which makes a lot of sludge that is easy to remove normal sludge takes time kind of like a plugged up artery to develop it is hard to remove.

On top of all that most BMW's and Mercedes have insanely large sumps so one bottle of anything is never enough you normaly need two of anything. SO if you where going to try a solvent flush like B12 and 5W20 oil it would take two bottle. If you wanted to try running MMO for the entire OIL change it would take two bottle to the sump plus your choice of oils. Auto-Rx would be more of the same it would take two bottles more then likely to do one treatment with some left over for the power steering or transmission.

Their is no such thing as a light weight oil cleaning method the old school 20Wt. Flushing oil where not street oils they had a boat load of solvents in them! They where thin to make sure the oil pick-up had a decent supply of oil just in case it was as sludged up as the rest of the engine!

So if you can afford 10W60 oil for that beast I fail to see why you can not afford two bottles of Auto-Rx? 10W60 is only sold at the Dealership and it is expensive!

So lets say this was my car and I had an attack of cheapness that over came me and I could not break free! I would pick up two pints of B12 Chemtool and add it to your exhsiting oil with engine cold then start it up. I would drive the thing around for at least an hour to get it nice and hot and to make sure the RPM's stayed up and also varied!I would also put on a clean cheap store brand oil filter before doing this to catch anything free'ed up. I would then pull it into my pole barn and I would drain the oil. 99% of the light aromatic hydrocarbons in the B12 will have cooked off dureing the first 30 minutes of driving and anything free'ed by it will be in the clean filter you put on before the drive. Now drain all the nasty black oil out. If this car holds 8 quarts then pick up 7 quarts of M1 0W40 and 1 quart not pint but quart of MMO. Put a good filter on now drive as normal for the normal oil change interval.

M1 0W40 is advertised on M1's site as beign able to remove sludge and varnish from engines left behind by other oils. The MMO is also advertised as being able to do some cleaning of sludge and is safe to add for the OCI. Continue to to use M1 0W40 until you can afford to do an Auto-Rx treatment.

If all you have is light carbon deposits, light sludge and medium levels of varnish the above should do the trick and is cheap!You could probably add up to 2 quarts of MMO due to the size of the sump but one is safer then two.