Why is your 1987 Mazda Rx7 turbo 2 overheating?

Answer 1

afraid this can be any number of things to a stuck thermostat costing £10 to a broken engine costing £3000.

bad news- if you've been driving around with it overheating there is a good chance that the housings have warped - under no circumstances should you use the car outside of a controlled environment (ie your driveway) as this will cause irrersable damage to the housing.

leave the car so its stone cold, then turn it on and leave it idling and when the car starts to warm do the following.

check the radiator gets warm?

if it doesnt, is the pipe going to the radiator warm/hot?

if the pipe is hot but the radiator is cold you have a blocked radiator - it needs unblocking at a garage or a brand new one buying.

if the pipe and radiator is cold then it the thermostat that not working, the housing will need taking off to get at the thermostat to check if its not working.

you can test the thermostat by heating it and watching it move but for the cost of a new one you may as well just replace it as you've just spent an hour taking the pump housing apart.

if this is ok that about rules out any of the minor problems.

so onto the major ones...

With the car cold start it and take the filler cap off, are there any bubbles?

is there any smoke from the exhaust when the enigne rev's?

but most importantly do you loose coolant?

if the answer is yes to any of these questions chances are there is an water seal faliure somewhere in the engine. the only fix is to strip the engine down and rebuild it.

you will need to do a compression test and a pressure test on the water system. both can be done at a Mazda garage but if your doing it yourself then you need

between 85-95psi on each rotor face for compression. remember there are three rotor faces so there should be three readings on each chamber making 6 readings in total. if you have a problem one or more of these reading will be very low or bearly even register.

the water system i believe shoudl hold pressure up to 19psi - please check this as im not 100%, 19psi is what is should be on a 3rd gen rx7 so may not be the same for the turbo 2.