Overheating in 2000 Mazda 626

Hey there,

Started having overheating problems with my 2000 Mazda 626 a couple of weeks ago. Initially, the problem was traced to an eroded seal that was leaking my coolant at high pressure.

The seal was replaced and coolant was flushed and all was fine for a week.

I noticed that the cooling fan was not coming on as it normally did (I used to notice it come on by itself when the car was off) and a few days later it overheated again. My mechanic checked the engine and suggested we change the coolant temp sensor as the fan came on when he disconnected it. The fan did come on after this but would do so unpredictably and not always when required. Suspecting a faulty after market sensor the sensor was replaced again. Now the A/C does not work although the A/C fan does come on and I have a check engine light. (He did reset after changing the sensor the last time)

Some folks are suggesting I change the thermostat, others suggest the relay, and we've checked the fuses.

Any suggestions as to the best approach?

Thanks in advance,

  freebass

Change the thermostat and the relay. Neither are expensive and it'd help to rid urself of the 'maybe its this' scenarios. Make sure u have a trustworthy mechanic, he could be just messing things up on purpose to make more money.

  VMJYogi

are you sure you dont have any broken gaskets o-rings etec. Maybey an air leak is causing your problems. Ive had problem that said chek engine and it turned out to be a oxigen censor.

  Kris

Thanks for the tip VMJ. I did change both the thermostat and the relay.
The fan comes on as soon as you start the car now whether its hot or not and there slow infrequent leaking of coolant still. Still checking to find a source.

Re: A/C, we've checked the freon and narrowed it down to no power getting to the compressor. I'll wait till we figure this out before worrying about the check engine light again as I suspect this will stay on until that problem is resolved.

One other problem has cropped up in the interim. After sitting over night, the car doesn't start properly. I need to crank it 3-5 times before it slowly kicks in as if its having trouble getting gas. Turns over well but doesn't kick in.

Changed the plus and plug wires and am about to change the fuel filter to see if that helps.

Thanks for any further suggestion.

  freebass