1982CorvetteDude

This isn't my 82......it's on my wifes daily driver - 2000 Grand Prix GT

I noticed a few weeks ago that the heat quit working, it just blows cold air. I replaced the thermostat because it was sticking...but no difference.

I was browsing some tech online and it said that if the car was low on coolant then it wouldn't allow enough hot coolant to the heater core to heat the air.

I pulled off the radiator cap and noticed a lot of brown clay-like sludge around the opening. I grabbed the heater hose, it was warm but after squeezing it I could feel the sludge stuff inside it.

After doing a search I found out that some of the antifreeze GM used had a tendency to turn into sludge. Not being familiar with coolant brands I added the store bought stuff in with it as soon as it got low (over the years). I never had the cooling system flushed before.

I figure my heater core is stopped up, but the car hasn't overheated yet so that portion is fine.

My question is: Can I take my car somewhere to have all this sludge removed / cleaned from the system without costing an arm and a leg? Is it something I can do myself? It would seem like it would have to be forced backwards than the normal flow with something pressurized?

Thanks again for any help

rihwoods

Was there ever Bars-leak used ??? If so,that stuff can clog a heater core and lower tubes of a rad....

Try a flush at rad shop......not sure on cost,but might work..

moosie982

It seems to me that all it would cost you is a bit of time and some water to backflush the heater core via the heater hoses, but do you think there is any kind of "sludge" in the block and radiator, maybe if you get the heater core cleared out you could run some flush thru the system to get the rest of the goop out. It also seems to me that somewhere along that year the General used anti-freeze that was kinda permanent in nature and if you mixed it with "regular" generic anti freeze it would gum up the system, dunno, maybe someone with more experience will chime in and sety us straight. Good luck , heat is important this time of year,,,Peace,,, Moosie

1982CorvetteDude

No bars - leak, everything had been ok until the heat quit working. That prompted me to open the radiator cap.

rihwoods

Ok..try this:


....do a reverse flush on the heater core seperate from rest of system. To do this first determine which line is in and out of heater core. Disconnect both hoses for heater core on the engine side of firewall so hoses are still attached to the heater core but not to rest of system. Buy a garden hose repair kit at hardware store the metal kind with barbed end that inserts into the hose and is female screw connector. Install this gadget on output side of heatercore and hook a hose to it. Turn on water and it will back flush the heater core and spit the garbage back out the (normally) inlet side.

If you can,use hot water....just hook up garden hose to washing machine "hot water" hose bib...

Rich

mayberg

My '96 Lumina had the same symptom - the heat didn't produce. The guys at the radiator shop backflushed the heater core and the problem was solved. Same thing - gunked up DexCool.

jackson

I've posted extensively on this very problem. A clear-cut DIY solution exists. Do a CF search including CF archives. Key words ... AS100 ... Prestone ... GM P/N 12346500 . Tip ... start calling your local GM Dealers' Parts depts right now & try to track down a canister of P/N 12346500 (apparently discontinued but there's still some out there).

ghoastrider1

You,or someone,have mixed the two brands of antifreeze,that cannot be mixed. The brown,sludge crp is the result. This happened to me with the wifes Grand Am. Yes, I did it.I wasnt paying attention. Flush,flush.flush,then cross your fingers...I ended up working on the darn thing for a few weekends,well ,more than a few. Never mix the orange and the green.

Gordonm

You cannot mix Dex Cool with any other type of antifreeze. It makes a mess as you have seen. FLUSH FLUSH FLUSh and hope it gets all the crap out.

1982CorvetteDude

Thanks for the replies everyone, I'm going to try the heater core backflush myself this weekend....I'm def going to run a line to my washer hot water fitting since it's under the carport. Hopefully I can get that crap out. I don't remember for certain but I bet I mixed coolants at one point in time.

MIKER

I had/have the same problem with my 2000 Chevy Blazer. No green anti-freeze had been introduced to the system. Adding green coolant is not the only reason this happens. DexCool can turn to crap all by itself. Do a google search for "Dexcool sluge".

This radiator was only 18 months old due to a minor fender bender.
I do not believe that it had a dexcool sludge problem prior to the accident/radiator replacement.

I thoroughly flushed the system with a Prestone flush kit.
I ran Prestone Super Flush through the system for about 6 hours worth of driving as instructed and then refilled the system using green anti-freeze and distilled water.
It's still a bit muddy. I plan to repeat the flush process this summer. I'm afraid that once the corrosion has started that there is no stopping it. I've read about intake gaskets failing because of this condition not to mention the possibility of freeze plugs starting to rust through.

1982CorvetteDude

Mine looks exactly like that....not as bad though....but close. Can you get the preston flush kit at wal-mart?

jackson

Super Flush won't cut the dexcool sludge from the entire system ... none of those wimpy parts store liquid flushes will either ... neither will backflushing ... it takes strong steps ... follow my post above ... IT DOES WORK ... squeaky clean ... AS100 / GM 12346500 IS what GM specifies in several TSB.

You can use the wimpy flushes/backflushing ... it'll probably get the heater working ... but you're just tinkering around the edges ... the whole system ain't gonna be clean and ... given enough time, it'll come back to haunt you. For many folks, this is the wrong time of year to be futzing around ... slam it hard & solve it for all time.

I had both GM pickup & Lincoln Town Car sludged up due to extended use coolants ... get the TSB and cleaner suggested below ... it works. Apparently the 12346500 is discontinued but there is some out there ... I had to call a few GM dealers to find it ... I was successful just a month ago when I found some & did the trick on my preacher's wife's late model grand prix. Replace BOTH T'stat & Rad Cap when you're done cleaning & neutralizing ... the strong cleaner will likely damage them if they're not already junk from the sludge.

-addendum- Heck I looked one up for you guys ... here a quote from an older post:
I'd suggest a real good coolant system CLEANING ... not just a flush but a real cleanout. Best stuff out there is at GM parts dept ... GM P/N 12346500 it's actually Prestone P/N AS100 Heavy Duty Cooling System Cleaner ... but you'll rarely find it anywhere but dealer ... under $10 ... strong powdered stuff, not those wimpy liquid flushes you'll find at WallyWorld or Advance ... wear eye protection. Get a free DexCool plugged radiator service bulletin (#99-06-02-012D) printout at GM dealer Svc Dept ... it'll walk you through a cleaning procedure that REALLY works. BTW ... proper procedure w/ AS100 takes about 4 hours at high-idle. Use the GM procedure/TSB as a guideline ... do it right and this stuff REALLY WORKS WELL!!!!!!

MIKER

I wouldn't mess with the Prestone super flush. I would take jackson's advice and purchase the AS100.
Thanks for the tip jackson!

Paul L

You would be wise to check the intake gaskets (lawsuit, see link below). Some leak into the crankcase and cause engine failure. Mine (2001 Impala) leaked at the back of the block and did not do internal damage. I noted pink puddles on the garage floor and loss of heat two winters ago. The DexCool had chewed up the gasket material. The repair bill was about $900 and GM denied me goodwill.

http://www.topix.net/forum/autos/bui...N4K8V7QD8GB/p2

GUSTO14

Dex-Cool certainly has it's detractor's, as well as advocates. Some will swear by it, while others can give very personal accounts of how it has failed them. It was originally intended as a replacement for the old green stuff that had been around for years with the big difference being in the extended replacement interval and it supposedly being more environmentally friendly,... along with a few other features.

I have used Prestone Green with complete confidence in my vehicles for many years with out failure and it has performed superbly. But I also change it every two years regardless of it's appearance. I have even used Dex-Cool in a number of vehicles that came with it as original equipment. I have not personally encountered problems with Dex-Cool even if I do have less confidence in it, but, I also change it every two years.

My recommendation to those that must use Dex-Cool would be to pay close attention to using it as directed, but most importantly, change it more frequently than is recommended by the manufacturers and you will have a better chance of avoiding issues. Perhaps eventually, they will be able to produce a coolant that can be everything to everybody... until then, no 5 year (or more?) change intervals for me.

Good luck... GUSTO

noonie

Here is a simple tip.

The good GM stuff is simply oxalic acid (commonly merchandised as wood bleach) and the neutralizer is washing soda.
This is an organic acid and available at most hardware stores. Both are much cheaper this way too. Please follow the free gm directions.

Some more tips.

-Let the engine cool before draining and/or filling coolant/water. This is where all the time will be spent.

-Use only distilled water with your antifreeze.

-Flush the entire system very well, to include removing the 1/4" NPT plugs on each side of the block.

-For what little it costs, change the coolant (antifreeze) once a year no matter what the label says. Even though the glycol part doesn't wear out, the anticorrosion additives do and you want to keep the ph neutral.

jackson

Hi! The AS100 canister label did state it is oxalic acid but was not clear on the neutralizer portion. I'm not a full-blown chemist but did take more than basic college chem.

I do want to find another source for the 2 dry components ... but I need a bit more guidance:

• Do you know what concentration each of the hardware store components are? Brand Names? Both dry?
• What is "washing soda"? ... Brand name?

Thanks for your suggestion ... can you expand on it a bit?

MILO

This is true. My wife's 2001 Olds Siloutte van had the infamous intake gasket leak. Luckily it was external and nothing happened to the engine. $950 repair bill for the upper and lower intake gaskets, all new hoses and oil change. Prior to 2003 they had issues with the gasket material. It applys to all GM V6, more common on the 3.4 than the 3.8 liters. Check your oil dip stick to make sure the level isn't rising. Good luck.

chris73cpe

prestone has some coolant out now that says compatible with all coolant types.. http://www.prestone.com/products/antifreezeCoolant.php
I've used it in both the vette and my grand am w/ dexcool this summer, so far everything looks ok, but I'll still be keeping an eye on it for the next few months.