Hot but mysterious

Didn’t quite make it back from the supermarket last Sunday, with the engine temperature shooting up & plenty of steam from underneath the bonnet accompanied by the lovely sound of a burbling brook… Sorry I mean coolant boiling. Fortunately this was at the end of the road from home. After checking both fans were running (they were) whilst admiring the growing pink puddle on the road, I let the engine cool down & topped back up via the expansion bottle/tank/aluminium thingy. Idling by the side of the road it didn’t take long to get up to temperature, see the fans kick in but with the needle continuing to climb until… Same again. And again. And again. Like the bastard son of Nascar & a traction engine!

Got home & left it until Monday evening, on the off-chance it was a one-off. However, able to boil the coolant from idle in a few minutes. Same again Tuesday. With no luck fault finding a quick call to Jay at Chariots to see what I should look at, & we identified that the radiator was cold even though the system was boiling over. So, the water isn’t circulating which suggests either thermostat or water pump. Another quick call, this time to Performance Parts who supplied the engine. As ever their technical support was brilliant & after confirming there were no known issues with the water-pump & that the impeller was metal, I ordered a thermostat. This arrived a few days later &, with the garage too busy to fit me in they very kindly lent me a socket set & I changed the thermostat. Very adventurous of me, though I do say it myself…

This did not seem to fix the problem at first, & I ended up giving it to the garage a few days later. However, they couldn’t reproduce the issue after leaving the car idling for 45 minutes (& stopping before it ran out of juice!). & it has driven well since, so I can only assume that a combination of a new thermostat, and diligent topping up with much massaging of the coolant pipes to remove any airlock, has done the trick.

Another Marcos adventure completed!