DexCool antifreeze forms sludge on Chevrolet Impala

Problem Data
Average mileage: 102,876 (45,000–224,878)
Engines affected: 3.4L V6, 3.8L V6
7 model years affected: 2001, 2003, 2004, 2006, more2009, 2010, 2011
22 people reported this problem
Viewing 1 - 16 of 16 comments
Same sludge. I didn't know what it was so I flushed the system, replaced a couple hoses a refilled with new Dexcool. The sludge continued to reappear. I have flushed again. I didn't know this may be related to the Dexcool until reading this site. The car now has close to 130,000 miles. I replaced the thermostat which fixed an overheating problem, but the thermostat may have failed due to sludge build up. My heater core does not work properly and I'm about to replace that. I also went and purchased a new radiator being that if there's sludge everywhere else it probably ruined the radiator also. Is my engine ruined? Do I have recourse against GM? I don't know.
I just bought this 2003 impala 3800 series 2 and it had a random miss fire. So needless to say I changed spark plugs and wires car runs like a champ. But as the car got hotter I noticed my fans weren't cutting on so by luck I decide to check the radiator and nothing but sludge brown like mud and thick. Anybody best steps from here???
Discovered brown sludge in neck of radiator fill port while doing routine check and maintenance. Obviously going to have more sludge down in the engine as the car now has 135,000+ miles on it. Don't mind doing a flush, or even two, but what can I use to clean this sludge, or do I even WANT to? Perhaps if I clean the sludge out, who knows what leaks may suddenly appear. If I can get it good and clean, with no side effects, I'd go back with good old green stuff, but local Walmart doesn't even carry the green stuff anymore. All they have is the "works with any color antifreeze" version. I'm not sure what's in that stuff. It does not say Dexcool anywhere, but I have to wonder what it is that's in the bottle.
Car started over heating unexpectedly and trying to see what's the problem
I have a 2010 impala with a 3.5 v6 and had a code for a coolant thermostat. Replace the thermostat and filled coolant and now overheats. Whats the issue?
Getting hot lot of sludge build up on radiatior cap replaced water pump previous and flushed system still gets hot
I just discovered white slime on the underside of my 2003 Buick Century radiator cap and radiator filler neck. I think this is uniquely a GM DexCool problem because I have never seen this slime in any of the many non GM cars I've owned in the past. I flushed the cooling system 6 months ago with equal parts DexCool and distilled water so i shouldnt be having any problem like this. I know GM has settled lawsuits in the past over there DexCool 100,000 mile recommendation causing peoples engines to fail but if theres still a problem with DexCool they need to change their formula.
I took my car to the dealership where I've been buying my cars, and having them do maintainence and service work. They told me that the price they quoted me includes a flush, replace a radiator hose and the sepentine belt. It cost $760.00! They advised me to have a radiator flush soon, unfortunately, they did'nt tell me that sludge was building up and more problems would be forthcoming. The second time I took it in they quoted the repair at $500.00. I asked why this new leak they found was'nt seen during my first visit. The advisor told me it is brand new! I just found out that there's sludge in my radiator because I inspected it yesterday! Now, I'm in the process of finding a reputable auto mechanic in my area, which is tough. I'll update this as soon as the problem is fixed. Thank you.
Kept on flushing radiator with cleaner putting more coolant. So far hasn't appeared again. First replaced radiator.
DexCool antifreeze formed brown gel-like sludge, first observed at radiator cap. Supposed to last 100,000 miles. Lawsuit settled for cases where engine failed. Flushed system and replaced coolant. Keep air out of system by ensuring coolant reservoir always at proper level and check radiator periodically by removing cap.
Not yet fixed. Brown sludge in the radiator which is causing the heater to stop working and the engine temp starts to jump around a lot.
I am not sure how this can be fixed other than that I am having to have work done to my car and replace a lot of parts that are damaged by the Dexcool turning to sludge. I have had to replace the heater core, water pump, and have had the engine flushed around 4 times. Now, I am being told I need to have the Accessory Belt Tensioner and Serpentine Belt replaced as well as the Power Steering Pump, Radiator Cap, and Thermostat. GE should come up for a fix to this happening in their Chevy vehicles!
I just took my car to Firestone because of no heat. They said the Dexcoolant in the radiator had turned to sludge. They refused to remove it and suggested I go to a dealer.
Black sludge in coolant resiviour also over heats after about ten minutes.
I just notice this brown like sludge today. Was doing a fluid inspection on my car today as I usually do every couple month or so. At 1st I though it was clay until I touched it and it was nice and soft. This sight said around 100,000 miles mine just has 91,000. Tomorrow I'm planning to do a full radiator system flush including the heater coil. I'll update in a month or so to let you guys know if it ce up again.
Intake manifold began to leak. During the repair, Dexcool sludge was discovered as the cause - eating away the gasket and pitting the manifold. A "universal" high performance coolant was used in place of Dexcool upon completion of the repair.