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The new coolant is green. The heat works when it is not overheating
The Blazer uses the orange DexCool. Mixing regular green antifreeze with it creates a brown sludge that will eventually clog all the water passages and the heater core.
After doing a little bit of research I found almost only rumors about Dex-cool (orange?).
Rumors:
1) Turns to sludge with other coolants
If this is true then by now (month later) all the Dex-cool in my system that was remaining should of changed to sludge by now and my current situation is the worse it will get.
2) Turns other coolants to sludge
If this is true then the more coolant I add of green (currently in there) the worse it will get
3) Turns to sludge with contact to air
This one seems to have a lot of support as far as rumors go. If being true this means all of the remain Dex-cool is likely changed to sludge form.
I think 3 makes the most sense, GM tries to make coolant that can patch its own leaks by hardening on contact with air, only it doesn't work how they wanted it to or maybe not as well with age. The signs on my car do point towards this. I have had a mystery leak I could never track down because it will disappear for months on end and then randomly reappear and cost me a gallon of coolant, then disappear again. I plan to take her to a mechanic tomorrow for a leak check as I noticed a small bit of green coolant dripping very slowly out of the car, but could not narrow down the location. If he can perform a flush of the entire system I may just take him up on the offer and get the rest of this S**t out in favor of green.
That's just me though, if anyone has any other ideas let me know. I ain't planning on letting this car die any time soon, and as far as I know what ever it is in Dex-cool that reacts it should eventually dilute.
I'm not a mechanic so can only talk of my personal experience. Before I joined this forum I put regular antifreeze in my Blazer. A few months later I started overheating. I did all the logical things like change the thermostat but it turned out that most of the bottom coolant passages in my radiator were clogged which required replacing it. Flushing with a garden hose and flushing chemicals barely did a thing.
As for loosing coolant...I was putting about a quart a week in the reserve and never saw anything under the car. What happened was that the intake manifold gasket was dripping into the engine valley and burning off. That lasted about a year until it blew and wound up with 2 gallons of antifreeze in the oil. The only good thing is it blew about 1/10 of a mile from the home so my wife just coasted down a hill to our house.
Took it too a mechanic up here. This is what he told me:
The sludge is from the Dex-cool breaking down from age, and the reason why it is still there after a flush is because a lot of it settles into the bottom of the engine block and requires draining from there. However even doing that will not get all of it out but will massively improve it. He also said to just keep removing the sludge as it floats too the surface.
So I bought a siphon and am slowly removing the coolant. As for the leak I've seen coolant under the car a couple times but he said ignore it as that may just help remove more sludge. Starting to think the leak is the radiator cap since it has a lot of play in it and the side of the radiator is wet sometimes, it does look like the original.
As for the leak I've seen coolant under the car a couple times but he said ignore it as that may just help remove more sludge.
Uh...what? Ignore it? That's advice I've never heard. I think you should be a little concerned about a LIM gasket leak like dobyken described. It's a very difficult leak to trace. But it's usually in the very back corner of the LIM on the driver's side. I dealt with two Blazers that had that leak (one mine, the other a friends). I couldn't see it clearly (and I use that term loosely) without a mirror and a flashlight. Where exactly are you seeing the leak end up? Under what area of the truck?
Last time it was the front passenger side. By the bumper, but it hasn't done it in a bit. Hard to tell when it leaks since it is parked on a gravel lot outside.
Been driving it 200 some miles (since last overheat and thermostat change) and no signs of a leaking intake manifold, or at least none I know of (Missfires, low power and rough idle). I've been checking the exhaust for smoke and have seen none, and the oil looks fine to me, still looks new (just changed oil) and no bubbles (I'm told bubbles and milky is what to look for in tainted oil).
The time before that I really wish I knew where it was. Was working on the alternator because the new one died while on warranty and then it just started leaking. Finished the job, looked under the car and saw a nice big puddle (bout 1/2 a gallon). Guy at the parts store thought maybe the water pump (is was dripping dead center, but there is a skid shield there so it could of been from anywhere), drove it home (5 miles, no over heating, normal operating temp). Took it to a different mechanic and he looked it over and said I was leak free (looked over, no pressure check). That was almost 4 weeks ago and since then I have filled it back up and have not leaked again.
Overheated 2 times since, first time replaced thermostat with a cheap one, second time got a better brand and the new brand has prevented it from over heating ever since (200 miles or so on this new thermostat where the first failed in 20ish).
The reserve tank shows no loss, and the top of the radiator just has sludge floating on the top when I take off the cap (I pick off the sludge). Not sure how to test rad cap, but it has a lot of play in it when it should be tight on.
On a side note, the last overheating I did have a leak, but it was by the tire and the overflow hose was wet, pretty certain it just got too hot.
I have set up a flush for the end of October (beginning of winter).
Think I found the leak... maybe but not sure what the part is.
On the radiator there is a hose on the top by the cap that goes to the reserve and then a metal coolant line directly below this. It seems like it is coming out just above the metal line but it is a very slow leak. Ran it for a few minutes and it maybe a drop came out. Question is what is the metal line, it looks like it is going under the engine. Could also be from me taking the cap off too...
That line is one of the transmission cooler lines....if the line is loose trans fluid will leak out. If it is indeed coolant then the radiator has a crack in it.
updating you on my status. I just replaced the temp sensor and replaced the thermostat again...was fine for 30mins idle then started rising in temperature again....I’m sure I have no leaks...it’s holding pressure and no loss of fluid ANYWHERE....I’m so stuck lol glad I have a second vehicle
smh #Stuck
09-20-2016, 07:20 AM
I think you should be a little concerned about a LIM gasket leak like dobyken described. It's a very difficult leak to trace. But it's usually in the very back corner of the LIM on the driver's side. I dealt with two Blazers that had that leak (one mine, the other a friends). I couldn't see it clearly (and I use that term loosely) without a mirror and a flashlight. Where exactly are you seeing the leak end up? Under what area of the truck?
