Good morning all!

I'm new to this forum and I'd like to ask for some help.

My girlfriend owns a 1989 323 astina SP DOHC and it has become a little sick recently. For some weeks now the car has hunted quite badly.. from (very roughly) 500RPM to 1200/1500 ish RPM and would on occasion stall.

There was nothing else wrong with the car at that stage so I suggested fuel injector cleaner which we've yet to run through the motor. Just yesterday the car overheated after a stint on the motorway. The reservoir was almost empty; the water that was in there was boiling. I pulled over and let the car cool down. I filled the cooling system up again (it took a couple of litres!) and noticed that my girlfriend had recently replaced the radiator cap. It is rated at 13lbs (I don't know much about mazdas but this seemed a little low to me - commodores are around 19lbs aren't they?) I thought that if the cap was opening prematurely then the cooling system would not be operating at correct pressure, lowering the boiling point and loosing coolant through the reservoir. This morning I thought I'd give her a chance to prove my hypothesis. I started the car (stone cold) with the radiator cap off and immediately the coolant started to "froth" and "bubble" (combustion chamber pressure forced through the coolant system?) The idle was notably rough and during a short drive I noticed that the car had no power (lost compression??) and blew clouds of whitish smoke. Although it did have a distinct smell, the smoke didn't smell like oil - perhaps steam mixed with exhaust gasses? What do you suggest? Does it sound like a head gasket? The oil is not milky but that would depend on where the gasket has gone, no?

Thanks for your comments.

 

SOUNDS LIKE A HEAD GASKET

BUT BEFORE MAKING THAT DETERMINATION...PERFORM A PRESSURE TEST ON THE COOLANT SYSTEM.

 

The head gasket is blown or the head is cracked, one or the other, or both. If it's not cracked be sure to have it resurfaced before you reinstall it or it will probably blow again.