Overheated 1098

[Mrs Norris]

I’ve always thought that the A series engine rarely, if ever, overheats. However, I’ve just acquired a fully restored Minor with a fully refurbished 1098 engine and refurbished rad and water pump. I’d just got home from its first trip (approx 16 miles), turned off the ignition and a great cloud of steam billowed from the engine bay. I let everything cool down then tried to top it up, but the water just ran straight out of the radiator and onto the floor. It looks like enough pressure has built up to split the rad core. It also blew the overflow pipe off from where it connects just under the rad cap.

What could have caused this to happen?

[mowogg]

Sounds like a faulty component to me or perhaps one of the hoses was not fitted ted correctly

[simmitc]

Check compression on all cylinders as a head gasket failure could pressurise the radiator, but it sounds like a faulty rad - split channel = loss of coolant = low coolant level = overheat. Could also be a faulty radiator cap as it should have rleased pressure at 4 psi.

[Mrs Norris]

Thanks for the advice. I haven’t had chance to check the compression, but it’s looking like it might have been a faulty cap. The rad had been professionally refurbished and definitely wasn’t leaking before the cloud of steam (no water dripped on my driveway). The engine was also fully refurbished less than 50 miles ago and had a new head fitted.
Either way, the rad is definitely faulty now and the company that restored my Morris has arranged to collect the car and will change the radiator and cap.

They will give the whole cooling system a thorough check and I’ll ask them to check the compression as well. Even if the head gasket was fine before, the pressure build up when it overheated may have damaged the gasket.

I’m hoping that after their investigations, I’ll know the actual cause. Otherwise I’ll be constantly worrying that it might happen again.