# Oil FLUSH and Coolant FLUSH Question.



## LordX (Jan 31, 2009)

My friend has Mitchell and it says that when flushing a car's coolant, to drain the coolant, and then fill the reservoir with clean water and run the car for 20 mins. I also got a little cleanser bottle from an auto place.

The thing is, I am converting this car from DexCool to regular coolant. Are there any other tips or tricks for this?

Oil: I once had an auto guy say that when flushing his oil he would drain, then fill the oil tank with 4 quarts of DIESEL fuel, then drain, then add new oil.

Is this legit or dangerous? Any suggestions?

Thanks for any tips!


----------



## Rehabber (Dec 29, 2005)

Why would you not want to use DexCool? The results from it's use have been good. And there is no reason to flush the crankase if you do regular oil changes.


----------



## md2lgyk (Jan 6, 2009)

Rehabber said:


> Why would you not want to use DexCool? The results from it's use have been good.


Right. Except for those pesky class-action lawsuits against GM over it causing engine failures.


----------



## Rehabber (Dec 29, 2005)

md2lgyk said:


> Right. Except for those pesky class-action lawsuits against GM over it causing engine failures.


 DexCool isn't the problem. The crappy plastic intake gaskets are the problem


----------



## LordX (Jan 31, 2009)

Heh, we can have the dex-cool argument all day long, but I am changing to regular coolant either way.

Anyone have anything to say to the original questions I posed?


----------



## jlc791 (Mar 17, 2009)

LordX,

I think you'll need to repeat your coolant flush process a few times until things are definitely running clear before making the switch.

As for the oil flush, unless you have some reason to believe that proper oil maintenance was NOT performed or that some contaminent got into the oil, I see no reason to go beyond the usual full drain and filter replacement. You don't give the age or mileage of the car but I'm going to assume you're not dealing with a 20 year old car with 200K where natural sludge might become an issue.

jlc


----------



## 47_47 (Sep 11, 2007)

Are you having coolant and oil problems (cross contamination)? Make and model?


----------



## LordX (Jan 31, 2009)

This is a 2004 Impala 3.4L 51,000 Miles.

I bought the car used, so I have NO idea whether proper oil maintenance was performed.

This is why I wanted to start fresh so that I KNOW what has been done.

So, was that old mechanic correct about diesel fuel as an oil flush?

Are there any risks to doing a thorough oil flush?


----------



## Rehabber (Dec 29, 2005)

Diesel fuel lacks enough viscosity to protect the main and rod bearings. It also will contaminate the oil change with what is left in the engine. Just change the oil regularly using modern oils and your engine will clean itself over time.


----------



## 47_47 (Sep 11, 2007)

Rehabber said:


> Diesel fuel lacks enough viscosity to protect the main and rod bearings. It also will contaminate the oil change with what is left in the engine. Just change the oil regularly using modern oils and your engine will clean itself over time.


I'm with Rehabber on the diesel. If you want to flush the dexcool, remove your thermostat and flush repeatedly. Then install a new one.


----------



## AdRock (Dec 4, 2008)

Remove the thrmostat and drain the coolant. Use a hose to to backflush the system. Pull both lines off of the heater core connecttions and backflush it also. Put everything back on EXCEPT the thermostat and fill it with water. Let it warm up and then burp the system. Go drive around for a while. Long enough to let it be at running temp for about 20 minutes. Also run the heater full blast while doing this. Bring it home, let it cool down, then completely drain the system again.

Put the new thermostat in and fill it up. Make sure you burp the system to get any air pockets out. Check the coolant level again after about a week.


As for the oil. Get a quality filter and run some Mobil1 Extended Performance for the next few cycles. It has some extra cleaning agents in it for the extended performance and can help clean things in the engine. I use it all the time in my Stang and have been very happy with it.


----------



## LordX (Jan 31, 2009)

how do I "burp the system"?

(As you may be able to tell, I am a relative car noob)


----------



## AdRock (Dec 4, 2008)

LordX said:


> how do I "burp the system"?
> 
> (As you may be able to tell, I am a relative car noob)


 
What model & year car is it? And what engine does it have in it?


----------



## DIYtestdummy (Jan 16, 2008)

LordX said:


> This is a 2004 Impala 3.4L 51,000 Miles.


Burping entails getting all the air out of the system so you have consistant pressure throughout, thus keeping the proper temperature. I'm not too familiar with that engine, but take a look and find coolant sensors and any place in the coolant chain that you can let air out. I use the back of the engine as a reference and either park on an incline or jack up the rear. DO NOT DO THIS WHILE THE ENGINE IS HOT. Unscrew the sensor and put it back when coolant seeps out of the hole. Fill with coolant if necessary.

As for the oil flush - use kerosene. If you can't find kerosene use a commercial engine flush or just put a quart of ATF in place of a quart of oil and change the oil after a few hundred miles. I doubt that there is any reason to do this, but a good way to find out for sure is to look in the oil filler hole or take the valve cover off.


----------



## RippySkippy (Feb 9, 2007)

Never heard of flushing an auto crankcase with diesel or kerosene. I have used the Luca Oil Stabilizer on my old truck (R.I.P) as a replacement for 1 quart of oil, every other oil change. I nearly eliminated the lifter noise...and the truck seemed to run cooler as well. So rather than flush, you might look into the additive products.


----------

