Radiator exploded during MOT!

[matt_fsr]

Put the Merc in for its' MOT yesterday around 9:30, got a phone call at around 12ish to say that the radiator had exploded!

Went down to the garage and had a look, and yes, it looks like the top plastic section of the rad had catastrophically blown apart, water was everywhere, all over the engine bay area, wings, floor, even some spatter on the windscreen!

I'm just glad none of the water hit the lad who was doing the MOT - apparently it just went bang big style as he was lowering it down on the hydraulic lift, scared the life out of him!

Anyone else ever had anything similar? The guy's looking into what might have caused it now, hoping it wont cost too much to fix, but I'm just happy really that no-one got scalded when it blew.

 

[matt_fsr]

Apparently it was passing everything so far, just had the brakes left to test

Brakes are fine, they stopped nearly 2 ton of Merc + 5 people in pretty sharpish not long ago, when the options were a hedge or tree!

It's a 1998 C-Class, should hopefully be cheapish to repair, either some new rad parts or 2nd hand whole ran chucked in should sort it. He's checking in case of blockages or anything today. Going to phone for an update shortly.

 

[matt_fsr]

Just like a BMW E39 then

Ha ha, must admit of all the things to fail an MOT on, the last thing I was expecting was exploding radiators!

Ah well, bangernomics - He's getting a new rad for it for £100 + VAT so shouldnt cost too much to fit it, he's a nice cheap chap.

Just happy that the rad contents didnt end up all over the apprentice monkey really.

 

[matt_fsr]

It got hot an reached too high a pressure for the old rad to take.

I've only ever had a rad start to dribble.

Would a car engine be expected to sit idling for ~40 mins or so during an MOT?

Ive never waited whilst one's been done so I'm not sure if thats something thats fairly typical, or whether its just laziness on the testers part on not turning off the engine when its unnecessary.

 

[matt_fsr]

Garage I use leave the engines running for the whole test, always been like that. Frankly if a car overheats due to this then its a heap of junk that deserves to fail. A working thermostat and rad fan isn't that much to ask really.

Thats a fair point but how would a driver ever know that theirs has failed, until the car is put under completely unusual 'non-driving' conditions such as sitting idle for 1hr without moving during MOT?

£425 bill. New radiator, new fan, new thermostat, new fan bracket, labour to fit and cost of MOT. Didnt fail the MOT on anything.

Now got 3 little dents in the bonnet to remind me of the event

As I said, I'm really more glad that its just a bill and some dents, not a young lad with half his face scalded off.

 

[matt_fsr]

Wow. Funny you should mention this. Two weeks ago I saw a c180 'elegance' of the same era, just an 1.8 but the exact same issue during MOT. Blew the expansion cylinder off the rad. Luckily again the bonnet was down for the tester and it was clearly a big bang lol.

Not entirely sure even now exactly how it came to be other than to say the temp had obviously risen enough to turn the coolant to steam, and boom, up it went. Bizarre.

Wonder if its' a common fault. Mine's the same 1.8 engine.

Might ring Merc, see what they have to say.

 

[matt_fsr]

You mean just like being a a very slow moving or stop/start traffic jam then?

Perhaps, but even in a traffic jam there'd be a bit of movement, and some wind blowing some air. Or you'd turn off the engine so save petrol if the jam was very bad.

Granted, the engine SHOULD be able to handle this situation properly, just unfortunate that it didnt. Age / wear and tear on parts seems to play a large part in it.

If nothing else, Merc may be able to advise garages that this could potentially happen on W202 C-Class 180's, and to check parts before an MOT.