Well, this was an unexpected event in my ford ka mk1 maintenance journey.
It looks like the head gasket has failed.
The car had been on a long journey. Although when the event happened, it was the following day after a 15 minute run, and the coolant temp light came on. Hopper was near empty. No sign of fluid in the oil, no mayo.
Fluid was added, and the car ran fine back to a safe place, no further sign of coolant loss.
At first I was hoping it was the heater control valve, but there was no sign of actual leak after running the car. There was some evidence of boiler over, but only very slight (a few tiny drops of red coolant near the hopper, but no large soaked area).
The RAC came out to investigate and did a exhaust gas check and reported there is a very slight colour change.
They then surmised that it seemed like the thermostat was not opening.
So, It looked liked the thermostat failed initially and then the engine cooked, even though the car was stopped quickly.
People may remember i did a major flush of this car's coolant system and replaced the thermostat 2 years ago. So, I’m a bit miffed the thermostat failed. I documented it here.
https://www.diynot.com/diy/threads/ford-ka-mk1-coolent-flush-query-and-questions.632020/page-2
Could that heavily lime-scaled coolant that sat in the engine for years beforehand have done more damage than i realised?
Apparently there is an issue with the thermostat housing (failing seal?) and a trapped air pocket that can cause thermostat failure like symptoms. (Need to check if this is true)
So, prognosis..... head skim and a new gasket? Like i said, no signs of mayo yet.
Thoughts on where to go next, much appreciated.
It looks like the head gasket has failed.
The car had been on a long journey. Although when the event happened, it was the following day after a 15 minute run, and the coolant temp light came on. Hopper was near empty. No sign of fluid in the oil, no mayo.
Fluid was added, and the car ran fine back to a safe place, no further sign of coolant loss.
At first I was hoping it was the heater control valve, but there was no sign of actual leak after running the car. There was some evidence of boiler over, but only very slight (a few tiny drops of red coolant near the hopper, but no large soaked area).
The RAC came out to investigate and did a exhaust gas check and reported there is a very slight colour change.
They then surmised that it seemed like the thermostat was not opening.
So, It looked liked the thermostat failed initially and then the engine cooked, even though the car was stopped quickly.
People may remember i did a major flush of this car's coolant system and replaced the thermostat 2 years ago. So, I’m a bit miffed the thermostat failed. I documented it here.
https://www.diynot.com/diy/threads/ford-ka-mk1-coolent-flush-query-and-questions.632020/page-2
Could that heavily lime-scaled coolant that sat in the engine for years beforehand have done more damage than i realised?
Apparently there is an issue with the thermostat housing (failing seal?) and a trapped air pocket that can cause thermostat failure like symptoms. (Need to check if this is true)
So, prognosis..... head skim and a new gasket? Like i said, no signs of mayo yet.
Thoughts on where to go next, much appreciated.
Last edited:
