# Engine Flushing - worth it?



## ebackhus (Apr 21, 2005)

Hey all!

In October we replaced our Lancer with a Jeep Liberty. Since we bought a used vehicle I can't say much about how faithfully the previous owner(s) changed fluids and performed maintenance. Being a Jeep it already has pretty low MPG but I'd like to do what I can to restore it to what it was when new. I was just reading about engine flushing on another site and it seems many manufacturers actually advise against it now. Is this just to sell more cars down the road or due to a legitimate non-need? I'd like to do it just to have a clean engine.


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## Corday (Mar 3, 2010)

It's more the long lasting qualities of the Coolant available these days. I still believe in flushing. If you can still find the Prestone kit that you put on the heater hose (after splicing), it's the easiest way to flush. The coolant doesn't actually lose its ability to prevent freezing, but it does cause acid buildup and loses anti-rust protection which does a job on the radiator and heater core. The "mouse milk" that DuPont used to make isn't around any more. It did extend the anti rust properties of the coolant. Maybe someone knows of a substitute that's compatible with modern anti-freeze.


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## Wrench97 (May 10, 2008)

Coolant flush or Crankcase flush?

Just change the extended life coolant after 5-7 years.

If you use good engine oil and change it according to the maintenance schedule(usually 5,000-7,500 miles your good.


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## Corday (Mar 3, 2010)

In Post#2 I stuck to the cooling system. As far as mixing kerosene with oil to flush the engine, that went out when I left my step-father's shop (1955).


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## ebackhus (Apr 21, 2005)

Crankcase flush in this case. The AC and heating systems seem to be running perfectly.


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## Corday (Mar 3, 2010)

Nah! I'd skip it. If you're really concerned, there are labs that will do a chemical analysis of your used oil.


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## Wrench97 (May 10, 2008)

Yep do not flush the engine, all motor oil that meets the current API ratings have plenty of detergents in the additive package.
If you are concerned just look at the bottom of the oil fill cap or top of the dipstick if you find black sludge then maybe the precious owner(s) didn't change the oil just use a good oil and change it 2500 miles a couple of times that should clean it up, or a chocolate milkshake looking substance you have a coolant leak into the crankcase.


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## Basementgeek (Feb 7, 2005)

I would not flush it with out a good reason. Change the anti freeze if you think it needs it. 

BG


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## ebackhus (Apr 21, 2005)

The coolant looks great when checked at the recovery tank. I didn't change the oil myself since I get $5 changes for the term of my financing. I didn't get to see if a spoon was needed to get it out. When checking at the stick it seemed to darken at the expected rate.


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## Corday (Mar 3, 2010)

If you want to spend a few bucks get the tranny fluid replaced by the new device that sucks the old stuff out, thereby doing a complete changeover and refill rather than the ⅓ most dealers did in the past unless they were willing to take all day.


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## ebackhus (Apr 21, 2005)

I'm used to driving a manual with a sealed tranny. Is the drain plug for the tranny just oddly placed or something?


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## Wrench97 (May 10, 2008)

No the trans holds 8+ quarts but most of it is in the torque converter, there is no drain plug on most of them you have to drop the oil pan to get the oil out and access the filter/screen. The torque converter has not had a plug to drain the oil since the mid 1960's so you only get 3-4 qts out by dropping the pan, the additive package in the new oil theoretically will replenish all whats needed when mixed with the old oil still in it.

Ford had a "debris" problem in the late 90's and developed the flush system to extended the trans life(or at least get it out of the warranty period) shops have been selling the service for all autos ever since...................


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## Basementgeek (Feb 7, 2005)

I think my 85 Totoya had a drain plug :>)

Sucking the oil out does not let you change the filter.

BG


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## kendallt (Feb 21, 2007)

Basementgeek said:


> I think my 85 Totoya had a drain plug :>)
> 
> Sucking the oil out does not let you change the filter.
> 
> BG


 Exactly, this is why you don't see drain plugs on automatic transmissions. Manufacturers want you to change the filter when the fluid is changed.


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