Engine Oil Flush??

[78240D]

Hey all! Where do you guys stand on engine oil flushes?? I doubt it's ever been done by the PO and with 128,000miles. If you were to do one, do you recommend ATF or store bought stuff? Thanks!

[superbeast1098]

If you are talking about basically doing 2 oil changes back to back, that would be fine. But if you are talking about using stuff that is supposed to remove sludge and varnish, I would advise against it. That type of stugg will do its job, and remove any sludge and varnish, but it also clogs your oil pump, and can possibly lower your compression,

[78240D]

Thanks! I guess I'll just stick to getting the engine up to operating temp (and then some,) and do the change, and do another soon after. Thanks!

[compress ignite]

YEAH,
It will also allow the gunk it breaks loose to clog all those tiny oil passages inside
the head and block.

Do Not Do It!

'Smartest thing you can do for an older dino-oiled MB is run a sump of Mobil
Synthetic BLEND oil through it.(The blend will start gently cleaning all the old
funk out).

Then after a couple of sumps of blend you can switch to fully Synthetic Mobil1.

[Hatterasguy]

On an old engine I wouldn't dream of it, your just asking for trouble.

But if you want to make the inside of your engine look like new use Delvac 1. Think of it like a slow engine flush so you don't clog anything.

I can't get over how clean the internals are of an engine thats feed real synthetic.

[Parrot of Doom]

Its a waste of money. Just use decent fully synthetic oil in the first place.

[fireman1073]

auto-rx.com

slow engine cleaning, dissolves the gunk

Steve

auto-rx is snake oil. They also constantly spam message boards trying to get people to fall for it.

No oil additives should ever be used in the engine.

[daw_two]

I've done it, but not on purpose. DARN it. I hate forgetting to put the drain plug back in. Lucky for me, I heard oil running onto the garage floor when I had only poured about 1/3 of a gallon. Quick, put the plug in. Then continue to pour. DARN it. Plug does not have copper crush washer on it. Let it go until next time.

[ConnClark]

I have used a small amount of ATF (1/4 a quart) in the oil just before an oil change. I only drove it about 10 miles before the change though. Marvell Mystry oil is basically 99% ATF. Other engine flushes are diesel fuel or kerosene. As people have said if you have a lot of sludge buildup its not good because it may dislodge to much crud all at once. If you have a lot of crud just start topping off with synthetic to start a slow cleanup. Then start using a mix of synthetic and dino oil for your oil changes. Then do full synthetic. It should probably be safe to add a little ATF at this point before the oil change.

I personally don't think running full synthetic oil is cost effective and just run a 50/50 mix of dino and synthetic. About once a year I add some atf before an oil change to flush more crud out.

Originally Posted by ConnClark

just run a 50/50 mix of dino and synthetic

Oil types should never be mixed, only one or the other.

[ConnClark]

Originally Posted by ForcedInduction

Oil types should never be mixed, only one or the other.

Thats a myth. It does not do any harm. It just won't work quite as well as pure synthetic.

http://www.mobiloil.com/USA-English/MotorOil/Car_Care/AskMobil/Mixing_Synthetics_Conventionals.aspx

http://www.carbibles.com/engineoil_bible.html

Originally Posted by ConnClark

Thats a myth. It does not do any harm. It just won't work quite as well as pure synthetic.

It's not a myth. Oil types and brands should never be mixed. Only one type/brand should be used at a time.

Oil already blended from the factory is one thing, mixing it yourself should not be done.

[ConnClark]

Originally Posted by ForcedInduction

It's not a myth. Oil types and brands should never be mixed. Only one type/brand should be used at a time.

Oil already blended from the factory is one thing, mixing it yourself should not be done.

Its a myth.

" Will I Harm My Engine By Mixing Synthetic Oil and Mineral Oil?
Dan Arcy Sets Us Strait

No, you will not.

No, you will not. This is an all too common misconception, and one with no scientific data to support it. "
http://www.imakenews.com/rotella/e_article000398800.cfm?x=b11,0,w

Even the guys at car talk agree on this.
http://www.cartalk.com/content/columns/Archive/2002/January/06.html

Unless there is some additive in one oil that reacts with some other additive in the other oil there will be no problems. There are no documented cases of this ever happening.

When you blend motor oils you blend properties. Mixing 30 weight oil with 5W-20w will give you an oil with viscosity somewhere in between 5w and 30w. Mixing a better lubricating oil with a inferior lubricating oil will give you an lubricant oil that is better than the worst of the two but not as good as the best.

[tobybul]

Not to side with anybody but I have not only mixed oil weights but also brands. All mfrs have to meet a minimum standard so technically, motor oils should be very similar if not the same. That is one reason why blends are made/sold. I would say same holds for ATF.

I would say that if you had to watch anything, it would be the SAE classification between oil for gas vs diesel engines. The diesels have some additives for soot control and other stuff that helps with the D's. THey are usually the CF rated oils.