I have had frequent problems with coolant boiling out of my overflow whole located on the top of the resevior tank. The temperature guage doesn't move, it stays at normal operating temperature until there has been enough coolant leak that the emergency low coolant light and beep goes off, then eventually after continued driving, the guage will then move towards hot. When the car is turned off, you can distinctively hear the coolant boiling and then eventually is pushed out the overflow whole like stated above. There is no leak from any hose I'm pretty sure because I've had some replaced as it is. I just recently had my radiator and cooling system flushed, hoping that maybe my radiator was clogged and needed cleaning and that was the cause for the "overheating." While flushing the system, the engine was running and as the mechanic tried to pour coolant into the top coolant cap(where the thermostat is located) it kept boiling out/being pushed out. The mechanic mentioned that it had too much pressure. What could be the possible problem, and how do I fix it?

 

blown coolant seal???

there a fix for it but i can find the thread or website, look for it

mike

 

as has been mentioned numerous times in other posts, buy the time the needle starts moving towards hot, the engine has already overheated.

when the low coolant light goes off, you should immediately pull over and cut the engine. continuing to drive the car will lead to severe overheating (as you have already experienced apparently) which will most likely warp the housings and cause the coolant O-rings to fail.

this O-ring failure results in exhaust gasses blowing into the cooling system and displacing coolant, which gets pushed out the overflow bottle.

the block-weld fix that was mentioned is only temporary at best and will only really work for marginal failures.

my advice? have your cooling system pressure tested to make sure, but I think that you're SOL in terms of resurrecting this engine.

good luck in any case.

-bill

 

Signs of o-ring failure:

1) On a cold-start the engine acts like it's running on only one rotor for a short period of time. This is usually accompanied by white smoke.

2) Black goo on the overflow tank dipstick.

3) Take the filler cap off and cold start the engine and let it come up to operating temperature. If the coolant appears to boil then exhaust gasses are leaking into the cooling system.

The only permanent solution is to have the motor rebuilt. Some people have had good luck with the blockweld fix:

http://www.scuderiaciriani.com/rx7/o-ring_fix.html

I believe this is only a temporary fix and it's just a matter of time before the o-ring completely fails.

 

Dupe