Mechanics

HEAT AND TRANSMISSION ()

1999 Chevrolet Lumina

Hi there!

(1999 Lumina Sedan 3.1, 116,000 miles.)

My questions are:

1) Occasional hard shifting in and out of 1st gear. Had fluid replaced at 85,000 miles as it was dark and a fair amount of chips. Had fluid replaced again, another shop at 105,000 miles. No check engine light or other problems. Fluid was not leaking at any time. Mechanic mentioned fluid was a little dark for being changed that recently. Very little chip contamination. What else can I try?

2) During cold temps, like the morning commute, I get almost no heat. The gage shows about 1/4" over the 100 deg mark for the whole 30 mile drive to work. The drive is highway speeds most of the way in. There is heat when the weather is warmer, or if I'm in traffic conditions. Had thermostat replaced in the summer, after temp gage was observed moving all the way to the red line, then as it opened up, I got heat and it indicated normal operating temps. Coolant was dark brown and had thick, sticky globs in the radiator cap. Drained and refilled coolant system (and broke stupid plastic drain valve in the process). Had intake manfold and valve cover gaskets replaced at 95,000 miles due to leakage, as I understand is a common issue with this particular engine around that mileage/age. What else can I look for? Is the thermostat defective, sticking open and keeping the engine cooler?

Thanks in advance.
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Cactusman
February 13, 2006.




It s possible the thermostat is bad, but you said the cooling system was drained and refilled, but was it flushed well. The heater core may be pluged.

Tiny
Chevy350guy
Feb 13, 2006.
I didn't flush the system at all. Just a drain and refill. How tough is it to replace the thermostat? I probably should have the radiator boiled out too.
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Tiny
Cactusman
Feb 15, 2006.
Yes have the entire ststem cleaned, and replace the thermostat, it is most likely sticking because of all the crap in the system.

Tiny
Chevy350guy
Feb 15, 2006.
I noticed low coolant level in the overflow tank, some spots on the driveway again, and a drip from where the valve cover and gasket meet. After a pressure test, the mechanic said it was the water pump squirting coolant in that area. Seem a bit suspicious? A water pump and installation costs over $250 so I don't want to do it if I don't have to. I still need an alignment and brakes so this isn't shaping up to be a good week!

(now almost 119,000 miles)

Tiny
Cactusman
Mar 31, 2006.
Be thankful you aren't dealing with my car. Water Pump costs $800. In any case, it seems you may have leaked oil into the coolant at one point and it has clogged up the cooling system. Imagine that all of that junk you found in the coolant is in the engine. Have the fluid changed properly and the thermostat may fix itself. The thermostat may be plugged with that same junk you found in the system.

Tiny
Mvannessjr
Mar 31, 2006.

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