teknics

ok i was driving spirited and all of a sudden a plume of smoke took hold of my car, knew it was coolant right away, first thought was coolant seals.



stopped noticed smoke only from bay, figured since i replaced the hole left side it had to be the right side.



sure enough heater hose (form under filter to the cabin) exploded.



any ideas as to why my coolant system is so pressurized or could it just be due to 14 year old hoses?



ive replaced the thermostat and gasket, fixed leaky thermostat housing, replaced turbo coolant hose, and radiaor hoses, replaced radiator with fluidyne, everything.



would a bad rad cap cause this?



kevin.

ColinRX7

14 year old hoses don't help..



But yeah a bad rad cap wouldn't let excess pressure spill into the overflow.. What pressure is the rad cap you have?

1Revvin7

I've seen it happen on several Rx-7s. I believe its just old hoses. Everyone should replace all hoses as soon as possible.

mazdadrifter

i think the stock cap is 12 psi, double check and make sure you cap is the same and that the diaphram hasen't rotten off.



you can get a pressurization kit from like sears or something for not too expensive, and try to manually pressurize the system to see if the cap is working properly.



or you can take it to a local mechanic who will check it for you.

teknics

i got a fluidyne rad and cap, its 1.1bar IIRC so about 15psi +/-1psi.



ill test my cap at the shop tomorrow hopefully its just old hoses.



thats like the ONLY hose i didnt replace cause it looked fine.



kevin.

1988RedT2

Fourteen year old rubber on a car with the underhood temps of a T2? Hmmm.



I predict you will have only as many more problems as you have 14-year old hoses under the hood.



Sounds like you are good to go!

turborotor

I replace that hose every 2 to 3 years no matter what! I also keep en extra one in standby in my storage bin.



I also replace all the hoses every 3 years or when they start/feeling weird.



C

mazdaspeed7

Check the line goign to the overflow bottle, the cap in the overflow bottle, and the nipple on the radiator for the overflow bottle for blockage. I had a problem with that before.

teknics

yea that whole thing is unclogged, it was my problem when i ran 100% water and **** froze in the rubber line, but i fixed that and am running a proper 50/50 mix now.



everything SEEMS to be fully functional now, im going to run it hard again tonight and check the coolant levels again hopefully itll be all good.



kevin.

ColinRX7

I ran a 75 water and 25 coolant mix (oh and a bottle of water wetter) in my rx7 for the summer.. I dropped the coolant out of the car and it's sitting in a jug in my garage.. Hasn't froze..



Cooling is more efficient with more water, no? I was curious to see if my mix would have frozen in the Canadian winter but I guess it didnt..