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Discussion Starter · #1 ·
Ok, this is on my friends car. It's a '95 4cyl ATX, with 101k miles.

First, his car wouldn't hold a charge, so we replaced the alternator and battery. Then, after that, his car started overheating, and we noticed the belt snapped, so we replaced that, and it was still overheating. We replaced the Thermostat hoping it wasn't the water pump, but it's still overheating, just not as bad, or as fast. We could onlymake it about 100 ft before it was over half way. Now after we replaced the thermostat and the belt, we can make it a few miles!

My bet is it is the water pump since it just turned over 100k miles.

If it is the water pump, should we just replace the Timing Belt and Tensioner while we're at it?!?!?!

Or is it something else, and not the water pump?
 
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^ Yeah, always try the cheaper route before jumping into a +$100 repair job. Bleed the coolant system to get rid of any air pockets, I've done it by rigging a funnel up to the filler hole and keeping it full of coolant while the air bubbles come to the surface. Just make sure the seal is tight and, I'm sure you already know this, but the car has to be running for it to work. It also speeds things up to have somebody rev the engine occasionally.
 

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How do you know the temp gauge is reading right...

Take the temp on both sides of the new thermostat. If it opens and closes then you know the car is at operating temp. If the cooling fan doesn't run constantly your in the clear. Or you could just replace every part until you find the problem.

i dunno about that, i like to keep my temp gauge in the bottom 1/4 that just me but seems like overhalf is pushing it.
Running your car in the low is bad for the engine. Engine that never reach operating temp create sooty oil and wear faster. I'm not saying your car has sooty oil... it might just have a faulty temp gauge:p
 

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Discussion Starter · #7 ·
Well, we flushed the coolant out, and put some new back in, and it drove fine for a little while this morning(2 am) then on our way back from wal-mart, it started over heating.
So we flushed again, and found a big air pocket i guess you'd call it..

What causes the air pockets?
 

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Discussion Starter · #9 ·
Yeah, it was fine, we could drive it for awhile, then it started overheating again..

We're gonna change the Timing belt, Tensioner, and water pump tomorrow, just for the 100k tune up.
 

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How to get the air out.

Leave the rad cap off

Run car with heater on and let it get to operating temp.

Watch for the flow of coolant in the upper rad hose (this mean thermostat is open)

Allow thermostat to open and close a few times, topping up with coolant when necessary.

This should get any air out of the cooling system.
 
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