Hi

Wife has just bought a fiesta zetec 1.25 and we noticed a coolant leak on in garage when it had been running a while and was hot. They said it was faulty tank and replace it, we have picked the car up now and left it running on drive today to test and same happens again seems to be coming from under expansion tank ??

would the car leak, over pressurise if there was too much coolant in it ? where does it leak out the bottom of tank, on further inspection there is no way that tank has been replaced

Another issue we have noticed is there is knocking/clonk noise coming sometimes when go over rough road bump etc cant see any thing loose underneath any ideas one of the steering joints ???

The garage is 4 hrs away so if i can get these problems done without going back there as i have lost all trust in them

many thanks

11 minutes ago, cymro1973 said:

where does it leak out the bottom of tank, on further inspection there is no way that tank has been replaced

The tanks are prone to micro-cracking. You can't really see the cracks with your eyes though.

11 minutes ago, cymro1973 said:

there is knocking/clonk noise coming sometimes when go over rough road bump etc cant see any thing loose underneath any ideas one of the steering joints ???

My guess would be ball joint, however it could be practically any rubber/moving part on the suspension tbh. You have to get the car up in the air and feel around with a pry bar and look for perished rubber/split dust boots on the driveshafts, ball joints, track rod ends etc.

11 minutes ago, cymro1973 said:

The garage is 4 hrs away

Unfortunately that's the gamble you take when buying a car half way accross the country from a dealer. If you were never going to be able to take the car back for warranty issues, you may aswell have saved £1000 and bought one privately. There are an abundance of mk7 fiestas around for sale, surely there was one closer to you?

Are you 100% sure it is coolant it is leaking?

It is very normal fo all cars to drip water on the ground from near the back of the engine as it only condensate from the air conditioning system.

If the expansion tank is over filled then the excess will get vented via the filler cap pressure relief. Check that when the engine is cold that the level in the tank does not exceed the 'Max' fill line.

They may have replaced it with 2nd hand one with same problem. Mine is diesel not petrol so not sure what pipes Go where on yours. I would think the reservoir would be quite easy to unmount so you can move it a bit to inspect around/under it. A dentist type mirror on a telescopic rod is quite handy. My last two cars were 150 miles away because I had specific requirements on the spec/colour/diesel, I did think that might be a pain if any problems but they were a bit newer.