Heater Core Flush?

CSR44 · 01-18-2005, 08:36 AM

Does anyone know what could be used to disolve some of the Dexcool sludge out of the core on my 96? I flushed it back in November with just water and it worked great for about 2-weeks, then slowly lost temperature until no heat at all?

blazee · 01-18-2005, 11:13 AM

Buy a Prestone Flush N Fill kit, it is a "T" that you install in your heater hose so that you can connect your water hose straight up to it and back flush it. Then use the Prestone Radiator Cleaner. Not the "flush" get the "cleaner". The flush is used for twenty minutes while idling. The Cleaner is used for 3-6 hours while driving, you just drain your system add the cleaner, fill up with water, then drive a few days with your heater on (you don't have to have the fan on, just the temperature control all the way up), then when you drain it all the sludge comes out leaving your radiator and heater core spotless. Then connect your hose to the "T" again and back flush one more time, this will get everything out.
After that Fill with a 50/50 mix of DEXCOOL ( or the green if you prefer, at this point your system is clean enough to convert) and distilled water. NEVER MIX THE TWO! You will have to keep topping it off over the next few days as the air is worked out of the system.

AND THE ABSOLUTE MOST IMPORTANT THING IS TO REPLACE YOUR RADIATOR CAP, WITH ONE NOT MADE BY AC DELCO. THE AC DELCO ONES THAT CAME ON THESE VEHICLES ARE DEFECTIVE. THAT IS WHAT CAUSED YOUR PROBLEMS IN THE FIRST PLACE. THE BEST ONE TO BUY IS THE "STANT" BRAND YOU CAN PICK THEM UP AT ADVANCE AUTO FOR ABOUT 5 OR 6 BUCKS.

The Prestone Flush N Fill ($4) and the Prestone Radiator Cleaner ($6) can be bought at any parts store and walmart.

CSR44 · 01-18-2005, 11:21 AM

Thanks,

I did the flush kit already, apparrently the cleaner works better. I already switched to the new Prestone green, I will NEVER be using Dexsludge again! Unfortunately it is about-6 deg. here, so I guess I will be without heat until it warms up this spring.

blazee · 01-18-2005, 11:31 AM

If you follow the procedure above there is a very good chance that you will have heat again. Have you replaced you radiator cap? even though you have gotten rid of the DEATH-COOL your cooling system will still work better with the proper cap.

BlazerLT · 01-18-2005, 02:13 PM

Quote:

Originally Posted by CSR44

Thanks,

I did the flush kit already, apparrently the cleaner works better. I already switched to the new Prestone green, I will NEVER be using Dexsludge again! Unfortunately it is about-6 deg. here, so I guess I will be without heat until it warms up this spring.

Chances are you didn't get all the dexcool out and the green and orange mixed to create gray sludge.

There is nothing wrong with Dexcool. The only problem is the rad cap and people not doing the proper maintanence like waiting almostt 10 years to replace the coolant when it was supposed to be done in 5.

CSR44 · 01-18-2005, 02:23 PM

I ran it for 20 minutes with the garden hose hooked up to the tee, so I know there was no dex left in it. There are no signs of grey sludge in the radiator, and the cross tubes are still clean and flowing. I did put a Stant cap on too before all of this just to be safe. I am noticing brown chunkies in the heater hoses again and the outlet hose is not as hot as the inlet so I guess some more worked loose from the motor.

blazee · 01-18-2005, 05:57 PM

The water can only clean where it can circulate. If there are sections clogged up. The water won't help that much, you need to use a chemical to disolve the sludge before those area will be cleaned.

BlazerLT · 01-18-2005, 06:00 PM

Very true, water dissolves nothing.

chcknugget · 01-19-2005, 12:09 PM

I just did my own heatercore flush a few days ago and now I have burning hot heat in subzero temperatures-> success! Cost: $1.50 (in quarters)

I went to a "diy" car wash and disconncted the 2 heatercore hoses and blasted it with the high pressure hose. There was definetely residue and "clay" in there, but it was whitish mud (maybe just mixed with water). It worked great, no mess, and ony took 5 minutes. The high pressure of the hose was more than that of a garden hose, and I think that did the trick.

*Note you have to let your vehicle cool down before disconnecting heatercore hoses. I didn't do this because my hoses weren't hot (because of blockage), but the block was still hot. Coolant was everywhere. Thank goodness it wasn't on my driveway.

BlazerLT · 01-19-2005, 04:29 PM

Quote:

Originally Posted by chcknugget

I just did my own heatercore flush a few days ago and now I have burning hot heat in subzero temperatures-> success! Cost: $1.50 (in quarters)

I went to a "diy" car wash and disconncted the 2 heatercore hoses and blasted it with the high pressure hose. There was definetely residue and "clay" in there, but it was whitish mud (maybe just mixed with water). It worked great, no mess, and ony took 5 minutes. The high pressure of the hose was more than that of a garden hose, and I think that did the trick.

*Note you have to let your vehicle cool down before disconnecting heatercore hoses. I didn't do this because my hoses weren't hot (because of blockage), but the block was still hot. Coolant was everywhere. Thank goodness it wasn't on my driveway.

Although it did help, you need to have your cooling system flushed and refilled with fresh coolant or the problem will quickly come back.

Don't start being cheap, get the job done properly.

flatire · 01-19-2005, 05:23 PM

Quote:

Originally Posted by BlazerLT

Although it did help, you need to have your cooling system flushed and refilled with fresh coolant or the problem will quickly come back.

Don't start being cheap, get the job done properly.

somewhere along the line i was told that if you use dexcool then switch to standard green it has a reaction with the residue possibly causing permanent damage to some components,not sure if its true or not.just thought i would mention it

fllatire

BlazerLT · 01-19-2005, 06:21 PM

Quote:

Originally Posted by flatire

somewhere along the line i was told that if you use dexcool then switch to standard green it has a reaction with the residue possibly causing permanent damage to some components,not sure if its true or not.just thought i would mention it

fllatire

What you heard is right.

Dexcool is used in our engines because it is non corrosive.

chcknugget · 01-19-2005, 06:23 PM

Quote:

Originally Posted by BlazerLT

Although it did help, you need to have your cooling system flushed and refilled with fresh coolant or the problem will quickly come back.

Don't start being cheap, get the job done properly.

It wasn't my goal to be cheap, but to get the job done as well and as fast as possible. It was way too cold to spend an hour (or an afternoon) trying to fix this problem as I have no garage. Aside from that the nearest autoparts store that has those flush products is a half hour away, and I don't have time for that either. For now the heatercore heats up fast and keeps me warm better than I ever imagined it could.

GMMerlin · 01-19-2005, 08:03 PM

BlazerLT has this under control fairly well, but let me add a note or two to this concern.
The problem is the heater core clogging up...the cause is the buildup of sludge in the engine cooling passages that are getting stuck in the heater core.
if you flush just the core, you are masking the problem not solving it.

Go ahead and spend the time to completely flush the cooling system..its better to do something right once than wrong a bunch of times.

CSR44 · 01-20-2005, 10:41 AM

Just a reminder when I say "Green" I am referring to the new Prestone "Geen" that is compatible with Dex-Cool. If you don't completely eliminate the Dex and add the "old" green Prestone, you will get a sludge problem after time.

Just my $.02

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