Dexcool Curse -- how to cure it?

[RickyCRX]

Okay, when I bought my Blazer around March/April of this year, the water pump, radiator and thermostat were all replaced by the dealership that sold the vehicle to me. They did a flush of the system to clean everything out, but I am not sure they cleaned out the heater core. At any rate, the new (orange) Prestone coolant in the vehicle stayed pretty clean for a good long while, but recently as it has been getting cooler outside (and I have been using the vehicle's heat almost daily), I noticed a strange behaviour from the vehicle's temp gauge (I am very in-tune with my cars). I would notice after slowing down from being at highway speed, the temp gauge would creep up to a little above 195 (probably around 200-205) even though I was coasting without using the throttle and had plenty of airflow cooling things down. Today I noticed after driving on the highway for 20 minutes I stopped for gas and got back in the vehicle and the temp gauge was right around 210, which is pretty normal. Only this time, the temp gauge didn't drop back down much once I started moving. Once I got home, I popped the hook and the radiator cap was COOL to the touch, after driving 20+ miles on the highway. Knowing this wasn't good, I waited about 20 minutes and opened the radiator cap, which, as I expected, was low on coolant.

Now here's where things get interesting and unnerving.

The brand new radiator that was just put in in March is now coated with all kinds of "crap" and sludge already. My radiator cap had a lot of reddish brown deposits on the underside of it, and even the overflow bottle (what little was left in it) even has crap in it. I ended up topping up the system with the orange prestone and water mixed together, but know I need to do something about this. First of all, I have NO idea where the coolant went to. The vehicle is not leaking anywhere visibly, nor do I think it's burning it. My heater core also does not appear to be leaking (no strange interior smells).

What do you guys think I should do at this point in time? I'm thinking that flushing the system will only be a temporary solution. My new water pump, radiator, and thermostat are probably all gunked up now... What is the real solution to get rid of this problem at this point? The vehicle is a 1998 Blazer with 128k miles on it. It seems to run pretty good other than this issue.

Any ideas/help/solutions would be great.

Ricky

[Matt 4.3 TBI]

How old is the cap? Did you replace it with the radiator? I was losing coolant this summer with no explanation, after replacing the cap it stopped.

The sludge is usually a sign of contamination (from green antifreeze, or oil) or Dexcool that's long overdue for a flush/fill.

[newblazerguy01]

Just had my radiator flushed and filled with prestone, but i also replaced my cap and there was crust around the seal..makes me wonder if it was changed??? also the reserve look the same :confused:

Id replace the cap either way if its not been done recently.they only cost a couple of dollars..

the temp on mine stays low since it was done...but i also had mobil 1 syn for the oil job at the same time..could be part of it...

maybe its the thermostat???

[bvr775]

dex-cool(the pink stuff) is actualy a wonderfull product as long as it is properly cared for. i've been prolonged exposure the oxygen will cause it to gel as well as adiitives and atifreeze(the green stuff) . Unfortunatly when it's time to replase it, it's time to replase it. it' supposed to be good for 150k but I would never push my luck. I maintain it like older systems. Once a year it get's flushed and replased and I've never had a problem with the stuff(exsept the time firestone put green in my wifes lumina), but Once it gels it can be a pain in the ars to deal with. The engine must be completely flushed along with heater core and radiator. by completly I mean completly. Then you must pressor test the system And it is imparitive that you replase your radiator cap. A small leak is very bad over a period of time as this allows oxygen to enter the system. I had to flush twice over a months time and in the end had have it profesionaly flushed to remove the the rest of the contaminated product, but I did put dex-cool back in the car and have not had a problem cense. Well there is the small matter of my wife running the car without oil and it currently sitting in the garage with a seized engine, but that's not a coolent consern

I don't know much about the orange prestone replasement, outher than it is suposed to be compatable with both antifreeze and dex-cool.
If your losing coolent it's not the product it's more likely something else causeing the loss. you described an orange residue in the radiator. More than likely you have a bad head gasket, but let's not jump the gun just yet. have you pressor tested the system? and have you replased the cap?

[OBI WAN]

I am another Dexcool liker. As long as its taken care off, its not a problem. ALso sounds like they did a sh*tty job of flushing the system if you still got gink particles.
Now the lose of coolant. Its not leaking anywhere , right? Have them pressure test the system and see if therre is a leak!!!! You maybe leaking it through the intaje gasket which is know to have problems. Once air gets into the system it'll cause alot of what your seeing!!

[RickyCRX]

Here's another problem...

I have been driving the vehicle a lot lately (put over 500 miles on it last week alone), and haven't had any problems with it other than a little detonation, which went away when I topped the coolant back up the other day. However, this afternoon I started the engine up after it had been sitting since last night and it made this horrible "metal on metal" tapping sound on initial startup and my oil pressure was VERY high -- almost up to 80psi. Normally it is just a little over 60 when I start it on a cold engine, but this time it was extremely high. The "metal on metal" sound continued for about 10-15 seconds and finally quieted down. After about 45-60 seconds, the engine was very quiet and sounded completely 'normal' although the oil pressure still remained quite high. I then drove about 7-8 miles to Lowe's to take a jackhammer back that I was renting and the oil pressure gauge was all over the place (still reading quite high) based on whatever RPM the engine was at. As I continued driving, it slowly came back down to a 'normal' number on the oil pressure gauge as the engine and the oil warmed up. Has anybody ever had this problem before? After I got back home (at which point the vehicle had run perfectly for the entire trip, aside from the horrible noise on startup), I parked for a couple of hours and left again later and everything was perfectly quiet as if nothing had happened.

I guess I'll keep driving it to see what happens tomorrow morning when I start up -- it has been colder here lately than normal (a couple of mornings in the 30's this past week), and the engine has been a bit noisier in the mornings on startup, but it quickly has quieted down -- but never ANYTHING like what I heard this afternoon. It wasn't even that cold this afternoon when I started it -- temperatures were in the 60's.

If anybody has any thoughts as to what's going on with this vehicle, please let me know. This is getting kinda scary and making me not want to trust this vehicle at all!!

Also, in regards to the radiator cap questions that you guys had -- the rad cap was put on brand new with the new radiator. And the heads were also taken off around the same time that everything else was done -- all the gaskets should be new for the heads, intake manifold, etc.

Ricky

[RickyCRX]

Update:

I started the engine this morning (temperature was ~43F outside), and it sounded perfectly normal. Oil pressure was exactly where it was supposed to be and the engine was quiet. I don't know what the heck caused all the racket and 'metal on metal' tapping noises yesterday afternoon.

Ricky

[bvr775]

that's metal on metal is normaly caused by a dry start. what weight of oil are you useing? It sounds like your useing too heavy an oil.

and haven't had any problems with it other than a little detonation, which went away when I topped the coolant back up the other day

this conserns me. Your overheating. A little low on on coolent shouldn't cause this(allot low is differnt story) Your loseing pressor from you coolent system. You need to check you heads and intake manifold for a crack or warpage and check you freeze plugs as well.

[RickyCRX]

I wouldn't consider it a 'dry start' by any means... No more dry than normal. And ever since it did it that one time, the engine has behaved completely normally after that one day.

I use 5w30 oil year-round here in south Texas.

As for the freeze plugs -- we haven't had any deep freezes this year. One morning it hit right about the freezing mark at my house, but didn't go below freezing. I don't know where else the coolant could be going other than the heads/intake gaskets....

I just don't want to have to tear into the thing to find this leak.

I added about 3/4 of a gallon of liquid to the cooling system (radiator and overflow bottle combined).

Ricky

[bvr775]

It's fairly common for freeze plugs to rust and leak. 3 qts is allot. you've definetly got a leak. from the dry start condition you described I'm willing to bet it's leaking into you crankcase somewhere. I would tell you to dump some bars leak in it untill you can find and fix the problem, but I don't know how it will react with the dex-cool

Have you done a pressor test on your coolent system? You should be able to rent the pressor tester at most parts stores if not they'er not that exspensive.
I may have been told wrong on this, but I've been told the orange prestone shows up under a blacklight.I'll have to go get some and test it to see.If so it should make finding leaks easyer.

[RickyCRX]

Haven't done a pressure test as of yet. I'm planning to take the vehicle to a local GMC/Pontiac dealer by my house this week and have the system flushed and 'cleaned' with this chemical made by BG(?) I think it is. Hopefully they will pressure test it at the same time and make sure there aren't any leaks.

Luckily, even with almost 130k miles on the vehicle, I still have an extended warranty that's good for another 3+ years (unlimited mileage).

Ricky

[Sexyblue22]

I have a 2001 S-10 and I've had some problems with the Dexcool in my truck. I haven't changed it, yet. I bought it brand-new and now she's got 60k on her. My radiator cap has crust around it and my ex-b/f was going to replace the cap and flush my system. I don't know if anyone else knows, but GM has a lawsuit against them right now about the Dexcool antifreeze. My oil gauge is very crazy. On start-up my oil pressure goes straight to 60. After she warms up, she falls down to about 40, while driving. When I come to a stop either redlight or stop sign my oil gauge falls down to about 20. She has always done this since I've had her. I called the dealership about it and they said some oil gauges are more sensitive than others. I've never had a prob. I also put Mobil 1 10W30 in her. The 5W30 is so thin, like water. I live in Georgia and she ran just fine.

[blazen]

my farther just had the ame problem with my moms truck (96 s10 blazer) they werent getting any heat. the trucks temp was fine but no heat in the truck. couldn't figure out what it was than he found a site theat said they had issues with the dex cool it crystalizes in the system. found out he put a new heater core in it last year and it was already cloged up. so he tried flushing the system and when he took off the hose from the heater core it looked like ice coming out but it was the dex cool crystlizing. he just did that this morning and he's only driven it once but he says its fixed.

[Jake Nac]

This is good site to check out if you want an education on antifreeze http://www.macsw.org/pdf/200410MS.pdf

This an article on the lawsuit
http://www.cwcd.com/CM/MassTorts/MassTorts5.asp

[firehawkclone]

I have replaced the H/C in my 98 last year,trust me you don't want to do this!Take the hose's off the fire wall and blow the H/C out with a water hose than flush the whole system.Now your H/C can leak on the passenger side floor boad or it can leak out the same hose that leak's the condensation water when you run the AC in the summertime.I'd pull the spark plug's and see if one/some are really clean.And for GP i'd check the dip stick for any sign's of leakage.

I got rid of the DEXCOOL! I now run REDLINE WATER WETTER and very little of the green stuff!

[extreme gmc]

i am getting my system flushed at 75k or whenever i see buildup begin. sound like a plan, jake nac?

[Jake Nac]

I don’t know the service history of your vehicle but I recommend flush and fill every 2 to 3 years regardless of miles and what your owner’s manual indicates. If you wait to see evidence its usually to late. Why take a chance on the destruction that is so common. Yes we see it almost daily, water pumps, radiators, water outlets, heater cores, intakes, ect.

You don’t want to expose Dexcool to air, you must purge the air out of the cooling system.

[RickyCRX]

Sexyblue -- your oil pressure gauge sounds like it's behaving properly. Mine, on these 'dry' noisy startups goes up a little above 60 at idle. If I raise the RPM to ~1500 or so, the gauge almost pegs itself at 80psi. I know this isn't normal, because it doesn't do this when the vehicle is running 'properly' and not making these noisy dry startups. Also, the one time it made that horrible noise, it didn't do it again for quite a while, but now that it's a little warmer outside, it's doing it all the time (the last three cold starts have been very noisy, sounding like the engine is a thrashing machine for the first 20-30 seconds). This morning I popped the hood and listened and it sounded like it was coming from the valve covers on both sides.

Now, here's the only thing that's different -- on this oil change, I went to a local non-Chevy dealership that does oil changes as well and had them change the oil. I had a coupon for $9.95 with a free car wash, so I figured what the heck, why not... Normally I have been changing the oil myself and putting a Delco filter on the vehicle, but this time around I don't know what they put on it. I also always use Valvoline 5w30 non-synthetic... I'm not sure what they use. Since I'm now due for an oil change, I figure I will probably change it out, put a Delco filter back on it, and put my Valvoline in it and see what happens. Hopefully there won't be any problems after that. If it is still noisy, I may try to mix half-n-half of synthetic and regular oil to see if it helps.