Sunday, 28 July 2019


A month ago, I was driving along, minding my own business when the radiator exploded. The coolant actually came up under the bonnet and showered the windscreen as well as making impressive clouds of steam. Turned out, the top part of the radiator is made of Bakelite, and after 154,000 miles, it had given up the ghost. The top outlet had disintegrated and the rubber hose popped off (centre of picture):

The radiator (and replacement air con fan) were easily sourced and arrived within a couple of days.

What was a bugger was buying new lower hoses to connect the (automatic) gear box to the radiator (the old ones couldn't be shifted and had to be dispatched with a Stanley knife). None of the usual sources had a clue how to get hold of them, except MX5 City who ordered them for me, fresh from the factory in Hiroshima. £67 incl. postage, VAT, duty, blah blah blah and a two week delivery time. An outrage for two bits of rubber tube, but saved several hours faff.

TBH helped me replace it all today (that is to say, he replaced it all and I helped him). I now have a shiny new radiator plus bits:

That's it, car sorted, it will run smoothly for the next decade and/or 50,000 miles. Which is what I say after every repair, as Her Indoors will confirm. One day it will be true!


James Higham said...

Wonderful opening:

A month ago, I was driving along, minding my own business when the radiator exploded.

Mark Wadsworth said...

JH, thanks. It's funny because it's true.

Lola said...

It won't have been Bakelite. It'll be some form of thermo-setting plastic. Which generally ages/fatigues with heat and vibration.

Mark Wadsworth said...

L, the AA chap described it as Bakelite, and it is pretty similar. But 154,000 is not a bad innings.

Lola said...

It's definitely not bakelite. The AA blokey was probably being witty.

Mark Wadsworth said...

L, he said "it's like the stuff they used to make telephones out of" and I replied "Do you mean Bakelite?" To which he answered "yes" if I recall the exchange correctly.

Lola said...

Bakelite is far too brittle to be used as radiator header tanks. From a quick Google search:-

"Because of the harsh operating conditions, the radiator tanks are made from glass-reinforced nylon, a plastic that features a high-softening point. The high-softening-point nylon plastic is what helps the plastic radiator tank withstand the pressure and temperatures involved."

How long to plastic rads last?

"eight to 10 years
Most auto mechanics feel that a properly maintained radiator should last for at least eight to 10 years. Older metal radiators, when well maintained, can last for the life of the car, but modern radiators are mostly made from plastic rather than metal, and plastic expands and contracts as the radiator heats and cools."

We use an aluminium alloy rad in the racer - which is the harshest of environments - lots and lots of vibration. It's been on it since 1996. Just FYI

Mark Wadsworth said...

L, they do all metal rads for manual MX5s, but I couldn't find an all metal auto one. Seems insane not to make them all metal, but what do I know.

Lola said...

MW. There will be someone making aluminium rads for racing MX-5's - but you don't really want to go there.....lots of ££££s.

For OEM supply plastic rads are by far the least costly. That's why they use them. Ally rads are very good for heat rejection, better than copper I recall, but they are more costly. I have just bought a specialist aluminium rad for the car I am building. It was about £150.

Mark Wadsworth said...

L, the racing alloy one was only £20 more than the one I bought. They're only tiny.

Lola said...

MW. Yes. But probably no good for the road as you sit in traffic a lot of the time which leads to heat build up. Racing cars very rarely and definitely do not like sitting still. Ours overheats if you idle on the grid for any length of time but will run cool when racing on most days.