hi folks

got a slight leak on lad's fiesta. there is dried anti-freeze on the bolt head and down the side of block on to sump

can't see it on the thermostat housing or above it, bolts are tight, so I think it must be housing of gasket gone slighty.

any tips/advice on replacing the thermostat ?

Hi tg,

I had this problem a couple of years ago.

In my case it was a case of a bad thermostat housing seal;

You need to remove the thermostat housing shown below.

The invoice shows the (2016) price of the gasket and a new thermostat from a Ford dealer;

The thermostat is seated beneath the larger of the two outlets.

The seal that usually causes this leak is the one beneath the smaller outlet.

Both Haynes and ford instruct removal of the alternator for access but it is possible to do it without this step.

However, you'll need dextrous fingers and the patience of a saint to get the four bolts out and back in!

 

This is where the housing seats;

I popped the new thermostat in first;

The seal for the opening on the right is probably where your leak is from.

I've read that the plastic housings themselves can leak but it's usually the gasket on the small outlet that fails.

 

Regards,

H..

 

bearing in mind the housing is plastic and not metal I would think there is a chance it could be warped. I would check. the way I would do that is maybe putting it on a pane of glass and seeing if I would slide a very thin feeler guage under it in various places. Unless anyone can think of a better way of checking it. there probably are some other ways people can come up with, I was just thinking off the top of my head.

sorry for delay, had problems with other car

ordered a new housing with gasket and a new thermostat with gasket

as i'm getting to old for this mucking around with cars (but can't stop myself, & don't want to pay garage prices) i'm going to take the light and altnator off route to get better access