Hi,

My Fiesta has recently been overheating. Here is a bit of background:

I live in Jersey (Channel Islands) and as such, only drive short distance, no more than 10miles and the speed limit is 40mph.

Back in December 2011, I had a faulty radiator drain valve, which caused all my coolant to leak out and I didn't realise until it was too late. I only drove it a very short distance to get home. I flushed out the radiator and replaced the coolant and everything seemed to be OK. But after a month or so, the engine started overheating and the coolant was boiling, but none leaked out.

It seemed to sort itself out and there was no problems for a while, until recently. Again, the engine is overheating and the coolant is boiling. This only started happening when I was driving in the UK a couple of weeks ago (2x 250mile journeys a week apart). Everything was OK on the motorways, but as soon as I got in any traffic (below 20mph and at a standstill) the blowers started pumping out hot air, even when set on cold and the coolant began to boil.

This evening when I was driving home, the Idiot light (there is no temp gauge on this model) came on just as I was pulling into the driveway and when I stopped, there was some steam coming out from under the bonnet. Turns out, the fluid leaked out through the overflow cap (approx 1litre). After I let the engine cool, I topped up the fluid with water (as a temporary measure until I can get to the garage for some more coolant.

I have changed the rad cap and it hasn't made a difference. I also know the thermostat is OK as when I squeeze the upper rad pipe, I can see and hear the fluid moving through the stat.

The radiator is warm at the top, but cold at the bottom. The upper rad pipe gets very hot and becomes highly pressurised, but the middle and lower ones are cool and no change in pressure.

The coolant looks a bit dirty, even after having been changed recently, but there is no sign of any white gunk associated with a blown HG and the oil is clean as well.

The only thing I can think of is that the radiator is blocked somewhere, but if anyone has any other ideas I would be grateful. I can do very basic mechanic work and have a Haynes manual, but have limited tools and nowhere really suitable to work, so I feel this may have to be a case for taking it to the garage, so I would like to be armed with a bit of knowledge under my belt so I don't get ripped off.

That is all the info I can think of, but if you need anything else, just ask.

Hope you can help,

Cheers