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99 Mazda Overheating

I have a 99 Mazda Protege LX. That is only overheating when I accelerate to hard. Like getting on the the highway. I have replaced the radiator and the thermostat and also got the system flushed, but it is still overheating! Any thoughts on what it could be I am so confused here!!!

You need to make sure that all of the air has been bled from the system, and that there isn’t anything allowing more air in.

You need to have it evaluated for a head gasket breach. When the engine is fully up to temperature, take a look in the coolant overflow (if its not pressurized). Rev the engine and watch for bubbles. Having a block test done to check for combustion gases in the coolant is a more reliable way.

Good ideas, cigroller…

I’d also throw in that this is EXACTLY how our 87 Camry behaved when its water pump was failing. It was good enough to pump through enough coolant when the engine wasn’t stressed, but accelerate a little harder, and the temp would spike easily. At 13 years old, this car could very easily be in need of a new water pump if it hasn’t been replaced already.

Yup, probably need a new water pump.