Why you need to flush your coolant....

[inmyshadow]

Just like all fluids in your car, they need to be changed once in awhile.

Today was the coolants turns again. You see, when I bought my current shadow nearly two years go the coolant was dark brown. You would have thought my car was cooled by ice tea.

Even after draining/filling the coolant when I swapped the head did nothing to improve the coolant.

Last year, I tired using Prestone's coolant flush along with the flush kit they have. That looked to have done the trick. The water was coming out clear. Fill up with coolant and take a short drive. Check to see if I needed to top off somemore, the coolant was brown again.

Last week, I added my FMIC. With now blocking off some airflow to the radiator, my temp wasn't were I wanted it. Considering my coolant was still brown, I decided to flush the coolant system again.

This time I went with a heavy duty flush. I used Zerex' Super Clearner. It was billed as being able to remove rust, scale and solder. Per instructions, I drained the coolant. Then added the flush along with filling up with straight water. The flush recommends 3 to 6hrs of operation.

I did all that yesterday. Today I flushed out the system again. This time, I didn't use the prestone flush kit. I needed to replace the thermostat and a coolant line for my oil cooler too.

As soon as I openned the drain ----, all this brown crap comes pouring out. I then flushed out the radiator, first through the drain ----. Then I removed the lower radiator hose and repeated.

I then removed the upper radiator hose and thermostat. I stuck the garden hose into the head. I flushed that for a few mintues until all the brown crap came out.

To finish off the flushing, I removed the heater hoses to my oil cooler. I then back flushed the heater core. Tons more brown crap came out. I hope this helps with the weak heat in the winter.

The results are awesome. My coolant is bright green. Now my temps are back in line with before the FMIC. Riding around town, my car bearly got over 190 degrees. With the FMIC, the temps were always above 200 degrees without the fan. After the flush, the temps are like before with the TII radiator/intercooler.

So, as I stated all fluids need to be flushed regularly. This includes power steering and brake fluid. I use to keep a bottle of flushed brake fluid to show friend's why they needed to flush the brake fluid.

This applies to all of us and our high mileage turbododges.

[Holley]

A good point, brake fluid needs changing after every 18 months of regular use to stay at optimum performance

My old SC didn't have this problem as the coolant and oil were changed every 500 miles ... because it leaked so much, lol ...

[magtec]

I then back flushed the heater core. Tons more brown crap came out. I hope this helps with the weak heat in the winter.

was the heater control valve still used in '91? if so and you haven't eliminated it already, now would be a good time.

for anyone else doing this: be careful using a garden hose on the heater core - you don't want to have to replace it...

http://magtec.rvglug.org/misc/lebaro...re/oldcore.jpg

[inmyshadow]

I do have a vacuum leak in my heater controls. The line going to the heater control valve is one of those lines I need to check.

I like that heater valve. Only car not to have one was my daytona iroc. It sucked to drive that car in the summer. It constantly blew hot air unless the A/C was on. I could have added it, the vacuum line was there.

And yes, I did use a garden hose on the heater core. But I didn't use pressurized water. I just hooked up the garden hose to the return line of the heater core. Then slightly turned the water one.

was the heater control valve still used in '91? if so and you haven't eliminated it already, now would be a good time.

for anyone else doing this: be careful using a garden hose on the heater core - you don't want to have to replace it...

http://magtec.rvglug.org/misc/lebaro...re/oldcore.jpg

[crazyace]

Why would you worry about blowing out a heater core this time of year? Better to replace it in the summer than have it strand you in the winter. Besides, we use a pressurized flusher at the shop that mixes shop air and the water to get all that crap out of a heater core. I have never seen one that we had to replace, we do many of them a year.

[gkcooper]

I bought a Dakota from a junkyard a while back and the coolant was slimy brown. I flushed three times with Prestone and it was still dirty. Finally, I drained everything that would come out and filled the system with distilled VINEGAR. I left it in there for two days. You can't imagine what came out! I flushed it again and then filled it with distilled water and Anti-freeze mix.

Now, it's perfect and the heater is nice and toasty.

Greg K. Cooper
Huntsville, Alabama

[Aries_Turbo]

yup, I use vinegar on my rinse cycle in my dishwasher.... it makes the dishes sparkle. I have well water and I get scale if I dont. cooling system is the same.

Brian

[Tony Hanna]

I need to do something similar to my old chevy truck. I've flushed it out with pure waster several times, and the coolant always ends up looking nasty.
I might try flushing it with pure water and then idling it with the cap off and a bottle of CLR/pure water in it for an hour or so.