My minivan is overheating, there is brownish sludge in the coolant, already had the water pump and the therrmostat replaced

PDHINGRA

MEMBER
2003 CHEVROLET VENTURE
3.4L
6 CYL
AUTOMATIC
179,600 MILES

My minivan is overheating. The temperature gauge shoots to the red zone within two to three minutes of driving and the engine starts to stall. I checked the coolant reservoir, it is filled up, but the coolant is brownish in color with rusty particles. This issue surfaced about a week back, so, I took the van to a car mechanic. He fixed a couple of leaks in the cooling system, flushed the cooling system and also installed a new water pump and a thermostat. The mechanic tested it fine and I drove it fine for a week. But, now, a week later the exact same issue has resurfaced with the exact same symptoms. I am not sure if the mechanic diagnosed the problem correctly in the first place. So, before I get ripped off again, I need some advice regarding what is the likely cause of this overheating problem? Thanks in advance.

3 Replies

JIS001

MECHANIC
3,408 POSTS

Check your upper hose first thing in the morning. If the hose collapses then the radiator cap is defective. Also, I would have it checked for air in the system. I usually use an air lift tool to pull the air out the system when it is empty. There should be a bleed screw at the thermostat housing. Usually opening it up and pumping pressure with the pressure tester will push out the air but you would need to do it several times until just coolant comes out. The brown stuff is very common on Chevrolet and Dex-cool. When there is air introduced from a leak the coolant starts to turn that color? You can try and wash it out, but it would be better to just replace the bottle. Also when pressure testing, have him recheck for leaks. The lower intake gasket on those always to seem to leak as well.

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