Since the build of my car I'm having some issues with one of the coolant hoses continuously bursting. This is on a MK3 Fiesta with a 1.8 Zetec but a lot of people on here seem to be running zetecs so see if anyone's had similar issues. The hose from the heater matrix to the rear of the thermostat housing keeps splitting in half and chucking coolant out, this is the third hose now it's popped. Could this be down to a faulty thermostat perhaps getting stuck? The car has had a brand new rad, waterpump, all the hoses were free from gunk and it's now been flushed with water and antifreeze at least 5-6 times when I've been working on the cooling system. All of the hoses I had fitted were used spares however, the one that's just broken though is a brand new one. I would like to get to the bottom of this before fitting a samco kit and popping one of those :/ Any ideas?
Not a Zetec expert. but first guess would be either an airlock or head gasket. I'd also be looking at the pressure cap, it should be releasing
the coolant pressure long before bursting hoses.
Ian
Hi, your problem could be caused by a partially blocked heater matrix would build up pressure.
None of the above -- only one part controls the pressure (& vacuum) in the cooling system is the pressure cap. On most modern cars the cap bleeds
off excess pressure at 1.5 bar on 1960's cars 0.4 to 0.85 bar was more typical.
Splits due to excess pressure can be spotted becauseas they run horizontal along the main axis of tube -- exactly the same as a sausage splitting
whe being fried.
[Edited on 29/1/17 by britishtrident]
I agree the pressure cap should be releasing excess pressure which fixing should solve your hose problem.
The next question is why is it building such a high pressure, is the expansion tank over filled or positioned too low in relation to top of the water
jacket?
What temperature is the engine at when it lets go? Is your sender and gauge correctly matched also.
Perhaps you could upload a diagram of your cooling circuit? Then maybe 'people who know these things' could see if there's a fundamental problem somewhere.
I've removed the thermostat and seems to be sticking closed when put in boiling water, car seems to be running pretty poor aswell in the mid range when giving it a boot fuel possibly because it's running colder than it should. Got a stat coming tomorrow so see if that sorts it.
quote:
Originally posted by ProjectSi
I've removed the thermostat and seems to be sticking closed when put in boiling water, car seems to be running pretty poor aswell in the mid range when giving it a boot fuel possibly because it's running colder than it should. Got a stat coming tomorrow so see if that sorts it.
quote:
Originally posted by rm0rgan
quote:
Originally posted by ProjectSi
I've removed the thermostat and seems to be sticking closed when put in boiling water, car seems to be running pretty poor aswell in the mid range when giving it a boot fuel possibly because it's running colder than it should. Got a stat coming tomorrow so see if that sorts it.
Colder? I thought it would be running hotter if anything with the thermostat blocked...less water circulating.