Normal to add 'Coolant' mixed with Water after Thermostat-repair?

Old 03-02-11, 10:35 AM
PineCone's Avatar
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Normal to add 'Coolant' mixed with Water after Thermostat-repair?

Toyota Camry 1998

Last week, I brought to the shop because of temperature-gauge under the dashboard stopped working, .... stuck all down to the lowest and didn't move it up even after one-hour drive in Highway.

The tech. told me 'thermostat' was a problem and fixed it. Two days later when I looked coolant/resevour, it's pretty low and I put half a cup of coolant mixed with water. Then, yesterday it got low again and I put another half a cup of water.

Someone told me that after thermostat-repair it's needed to add some coolant mixed with water, .... but not twice within a week?

Just wonder whether the tech. did a right job for thermostat?
Or, some other issue popping-up after thermostat?

Any clues on this would be truly appreciated.

Old 03-02-11, 10:49 AM
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He may not have gotten all the air out of the system after the repair. It would then be normal to have to add some. 1/2 cup isn't much. Your system might have 3 or 4 gallons in it.

Make sure you always check the level at the same time after similar conditions. As in drove 20 miles in the afternoon, parked it, checked the next morning.

Also...anything between the low and high marks on the container is fine.
Old 03-02-11, 12:49 PM
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modern cars have sealed cooling system. any repairs that allow air into the system, must be followed by proper refilling procedure that completely removes air out of it.
most Asian makes I have seen so far, even have a special air bleeder screw, usually somewhere in thermostat housing dome, or anywhere in the highest system point.

it takes some time to get refill done, as engine must be brought to hot, so that thermostat opens. Also, heater core must be set to hot position, allowing coolant flow into it, as it changes general coolant volume for the system.

if air is not removed, it can create an air plug, like an emboly, and impair or totally stop proper coolant circulation through the system. leading to system overheating.

have no doubt your technician had all this done. but, also, if it's done, then coolant level in expansion canister should be dead on the same mark night or day, hot or cold.

i just had water pump replaced in my Camry, and am witness to that. I even draw a Sharpie mark on canister - and it's right at that mark ever since they fixed it.

I am, as of now, assuming that system was refilled on cold, then, through normal driving, coolant was sucked into the system, creating low condition in canister. which should have been corrected with the 1st refill. having 2 refills in 2 days.. I'd become alert to this. Not worried, alert.

if your car is parked in garage overnight, slide a clean piece of cardboard underneath and check on it in the morning. Look for colored, oily in touch fluid. coolant is oily in touch. also, locate your thermostat housing, and, if possible, shine light around it and look for any leaks, or sediments. anywhere around housing itself, hose, etc.

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