Help flushing anti freeze!!

[jbaker]

Tonight, I was putting my new overflow cap (radiator) on, and I was noticing how brown the inside of the plastic jug looked, so, I took the pressure cap off, and looked inside... BROWN... Nasty! So, I HAVE to get this thing drained/flushed... Is this a serious pain in the arse like I'm hoping it's NOT????? Tips, advice? I obviously can't do a thorough job just draining it from the bottom of the radiator....... My car has spent it's entire life in CA, and was transported to MA a week before I bought it, so I'm almost wondering what he was running in there?? It in NO WAY resembles Green Anti-Freeze!!!!!!

Jeff

 

[c4cruiser]

I believe that 95's came with Dex-Cool extended life coolant as the factory fill. The coolant color should be orange, or probably a brownish color if it's dirty.

The flushing procedure involves not only removing the radiator drain plug, but also the knock sensors at either side of the bottom of the block. I wouldn't use any sort of a chemical flush as it could cause problems with the aluminum components. Re-filling the coolant also involves opening a bleed valve above the water pump and the opti-spark to get trapped air out of the system. Getting water on the opti may ruin it (and your day and wallet). Distilled water should be used for the refill along with 2 gallons of coolant. Use the Havoline Dex-Cool for refill; it's not much more expensive that the green stuff and Havoline is what was used at the factory.

If you don't want to do it yourself, take it to the dealer or a reputable radiator shop and make sure they tell you that they know the specific procedure for flushing the Corvette system. It's a bit more involved that most systems. The service manual for my 92 even says you have to go through 3 cycles of coolant temps from cold to hot operating temp before any high speed operation is done!

 

[jbaker]

Ugh! Ok, well I just got an email, from a friend of mine that has a '96,and he basically confirmed what you said. I was mistaking my "brown" for the orange Dex-Cool, just looked a little dirty.. But, and correct me if I'm wrong, he said he's drained/flushed/refilled his at the end of each season and used Prestone (or an equivenent) green anti-freeze... Is there any problem with this?? I'm assuming the Orange is basically just a longer lasting chemical, and doesn't have any special properties that Green doesn't contain??
So, what he advised, this time, was to drain the radiator, from the bottom, and keep pouring fresh water into the filler, until it comes out of the bottom of the radiator clear, making sure to start the car a couple of times, but keeping the supply of fresh water going in... After that's all done (About 4-5 gallons of water), refill with 50/50 mixture....
Sound OK or cutting corners??

Jeff

 

[ErnieN85]

Depends on how long your going to keep it! The Dexcool has a much lower quantity of abrasives. translates to less wear on the waterpump impeller and seals also it protects better against corrosion. which means longer between changes of the heater core (a real nasty job)

 

[Rabbit]

Try this site for info re; coolant types.


http://autorepair.about.com/library/weekly/aa052601a.htm

 

[BigRed]

Thing I hate about Dex cool is, if it loses its water throughout running the vehicle it turns into a nasty gel brown crap substance that actually eats out your plumbing.

GM actually warns about this and if you "neglect" your cooling system and take back the vehicle with chewed out parts, they'll tell you to take a hike.

(Happened to a friend of mine on a 99 Jimmy)

So I had to fix it.

You can convert to Green No problem. Only thing is Green people can't convert to Dex cool (Why??)

The Plumbing in Dex cool systems is larger (Pbly to allow for all the gunk to travel)

My vote? Pull it out and replace with Prestone Green.

Take off your bypass hose and rad cap (After draining system from lower rad hose of course) and hook up a garden hose and basicly walk away for awhile. Come back and reverse flow. Keep doing it till the water comes out the other end clear. Then drain system again now add Coolant.

Enjoy!

 

[Eagle85C4]

BigRed has the ticket for you...I always remove one of the smaller hoses usually off the heater core return and hook in the garden hose...start water and engine...let it go until you got clear water. Then drain as much of that as you can and refill with 50/50 mix of distilled water and the green stuff.
I tried to put the dexcool in my 85 thinking newer is better theory and it was a big mistake. I will stay with the trusted and proven green stuff....

 

[jbaker]

Ok, I'm going to finish it tonight, so I'll pick up some distilled water, and go from there. My question is this.. If my car had orange stuff in it as of last night, ('95) how do I KNOW if it came with this out of the factory?? I've read a lot of the horror stories online about Dex-Cool, so I think I'm going to stay away from it. I like flushing my systems every year, two at the LONGEST, anyways, so it won't matter.
Last thing, if I do not let the fill tank get so low that it's sucking air in, is the need to bleed the system still important? I figure it's like doing your brakes, if you don't let air GET IN, you don't have to bleed air OUT??

Jeff

 

[jmccloud]

Red vs Green

Early 95's had green antifreeze (up until May '95 or so mfg. date)
Later 95's had red and a prominent label under the hood.
Use NO flush chemicals, just water (per service manual).

 

[wx briefer]

On the other side of the issue, I refilled with dex-cool. I found a great deal of information on the web that basically just warns against slow leaks from, among other things, a defective radiator pressure cap. Just make sure the cap is good and you should be OK with the original stuff.

 

[jbaker]

OK, the antifreeze has been VERY thoroughly drained, and I ran about 4 gallons of clean water through it, running the car on and off until it flowed completely clear. I let it drain, then put the plug back in.. Now, I filled it up with 1/2 Distilled water, 1/2 antifreeze... Figured I'd let the car run, in the driveway for a few, to warm up, then take it for a quick ride... So, I look, engine's up to 185, I figured the T-Stat should be opening soon, and will dump it back down. I take off, 190, 200, 210, 220...230..240, 245.. Ok, I turn around, and head home.. Now, keep in mind, I've NEVER clicked the "Gauges" button before to see what my temp's running, so I don't know what's normal, but, at the bottom, when in ENGINE TEMP mode, it says COOL "F", it stayed that way till it almost hit 250, then went to HI COOL, and I saw the temp drop like a rock, to 210, and it went back to COOL F. Is this normal?!?!??! Do these run this hot, or dooes it sound like my T-Stat might be giving me some troubles? It's only 44 degrees out right now, so I'm a little nervous about the first 95 degree day!!! HELP!

Jeff

 

[jbaker]

Ok, sorry for answering my own posts here, but I wanted to keep it updated. I've been down there, and have bled the system several times, now it's nothing but fluid, no more air, even with the upper reservoir cap ON. Fluid levels, after 3-4 full temp runs is up to par, and overflow is full.
Car seems to be running around 225 in my garage, at an idle. It climbs higher, but the fan(s) kick on. What's the deal here, is that too high to be idling at on a (now) 39 degree night???? Should I swap in a lower T-Stat??

Jeff

 

[newvette]

Jeff,
Your condition is normal for a stock cooling system. You could go to a lower t-stat, many people do. I have not and have never had any engine problems.

Mike

 

[jbaker]

Jeff,
Your condition is normal for a stock cooling system. You could go to a lower t-stat, many people do. I have not and have never had any engine problems.

Mike

Excellent! Believe it or not, that's what I'm reading/hearing around. It's just a high temp when your used to the 'old days' of cars running cooler, but getting 8 MPG . I'm gonna put a 180 Tstat in, still the same, I think.... Plus I'd like to look into getting the fans to come on a bit earlier.....