Hi, got a query about a family members MK7.5. They were driving the other day and steam started coming from the bonnet along with a bit of a weird smell, so they stopped and opened the bonnet and steam was coming from around/below the coolant which was bubbling a lot. I've done some research and seen that the bubbling/boiling could just appear that way due to it being pumped around, but this looks a lot more animated than that (see video - https://youtu.be/3FK3unikLKE )

We went to our local garage who we've used for decades, and think we've been messed around a bit, they've gone downhill since the old manager left, they just replaced to springs/coils on my focus and broke the driveshaft at the same time (brushed it off as something that can happen when doing the job). 

First they said the steam was due to a faulty 'switch', then after a day said they got mixed up the fiesta doesn't have a 'switch', then they blamed a faulty fan, so replaced the fan (£180), then a bit later said oh actually it's not the fan, but you still needed one anyway (yeah right), then said the fan only works if the air con is on so it's a relay, but they don't do electrics so call someone else, then they've now said it's the ECU. Most of that seems unlikely to me, temps have been fine when I had a look.

At the moment we're not really any further and have the car back with a new fan and -£180 and no real idea of what was the issue. I've hooked it up to Forscan and no DTC's, the car seems ok now (unsure if the fan does need the aircon on or not atm), but do we just use the car and see what happens?

Thanks

 

Try and see if there any cracks on the coolant tank, the cap and the hoses that connect to the tank, all are common to crack and leak, all of them are fairly cheap to buy and easy to replace.

sorry but any mechanic should have given that area a good looking at first.

time for a new  mechanic i think

OK, so no more bubbling or losing of coolant so that's good. So the levels must have dropped due to it bubbling over. 

So the issues seems to be the fan only working when the ac is on or it overheats (so I'm told). Anyone know what could control this? Does it need an auto electrician or is it possibly a relay like I vaguely found on Google. And if so which one? 

Any ideas? Cheers 

Possibly the temp sensor for the fan, if you find out where it is, bridging the plug out would bring the fan on straight away, if it doesn’t then the fault is another part of the circuit.