1997 radiator problem

[tmclaughlin]

my 97 bravada started acting up a little in the winter. my therostat would go all the way up and my check guages light would come on and then go back to normal. it wasnt overheating because it would do this right after i started it up. i checked my coolant and there was a rust colored sludge under the radiator cap and at the entrance of the hole i cleaned it out and put about 1/4 of a gallon of dex cool in. it seemed to solve the problem with the thermostat. i read about people having to spend alot of money to fix this sludge problem. i put the rest of the gallon of dexcool in since the winter but i still am getting a little build up of sludge. my question is would i be in too deep with the sludge to solve it with a radiator flush?

[Chris Stewart]

A radiator flush is a good idea and putting Prestone long life orange stuff is what I used on my '97.
I was emailed that the sludge is stop leak pellets thrown in the motors when they were new to combat leaky gaskets and I believe it because after the flush, I started loosing coolant in the winter so I put some Prestone sealer to take care of that.....no wonder people aren't buying GM.

[blazee]

The sludging is a common problem with Dexcool. GM made an announcement that the sludging is caused by faulty radiator caps, allowing the Dexcool to become contaminated. Under perfect conditions Dexcool is superior to other anti-freezes, but it is very easily contaminated. Once contaminated it quickly turns to sludge. To avoid problems, make sure you keep the proper coolant level at all times and flush and refill the coolant every 3 years and replace the radiator cap with a new one. You should replace your rad cap with a "stant" brand 16 psi cap, they are sold at advance auto. ( Do not use AC Delco rad caps)

If you have a leak, you should address it before performing the flush. Flushing the system can cause leaks to worsen. (not good if it is an internal leak) These are the flushing techniques that I recommend:

For system with Sludge:

Buy the following:
2 gallons of distilled water $1
2 gallons of Dexcool* $20
Prestone Flush 'N Fill kit $3
Prestone Radiator "Flush" $3

Turn your heater on and leave it on for the entire process

Drain the anitfreeze from the system.

Install the "T" from the Flush 'N Fill kit and follow the directions that came with it.

Disconnect the water hose, close all the drains, add the Prestone Flush, fill with water, get engine up to operating temperature and run for 20 minutes, allow to cool then, drain the system.

Connect your water hose to the Flush 'N Fill "T" and flush one more time. Drain.

Fill the system with a 50/50 mix** of DexCool and distilled water. Continue to fill the system over the next few days as the air is worked out of the system.








For clogged, neglicted, or extremely dirty systems:

Buy the following:

2 gallons of distilled water $1
2 gallons of Dexcool* $20
Prestone Flush 'N Fill kit $3
Prestone Radiator "cleaner" not "flush" $5

Turn your heater on and leave it on for the entire process

Drain the anitfreeze from the system.

Install the "T" from the Flush 'N Fill kit and follow the directions that came with it.

Disconnect the water hose, close all the drains, add the Prestone Cleaner, fill with water, run the engine 3-6 hours (you can leave it in for a few days if neccessary), drain the system.

Connect your water hose to the Flush 'N Fill "T" and flush one more time. Drain.

Fill the system with a 50/50 mix** of DexCool and distilled water. Continue to fill the system over the next few days as the air is worked out of the system.



* If your vehicle was made prior to Memorial Day 1995 or if you don't want to deal with the problems associated with Dexcool, get the standard green antifreeze.

**When you do your final drain and fill....not all the water will come out so to get the proper 50/50 mix you should add the right amount of straight Dexcool then top off with the distilled water.

[Chris Stewart]

Of course GM says that....I read about the supposed "crusties" too....
I just flushed the old stuff out, put in 50/50 orange Prestone long life & water, some Prestone sealant and that's it...4 years now.

[tmclaughlin]

i am going to try this thanks for your help