Hi guys...my Daughters 04 1.3 Ka with the Duratec engine has developed a coolant leak from the area around the plastic thermostat housing,

I dont want to disturb it unnessersarliy....its hard to see exactly where its leaking but I see from the manual it has an O ring....

I wonder if its a simple as just replacing the O ring or do the housing have any faults...

I have seen them on ebay from around £20 to £40...are the pattern ones ok if I need one.

Nick in Cheshire.

Hi Nick and welcome to the forums,

Plastic thermostat housing are prone to leak as they can warp. It could be the seal but personally I'd rather just replace the lot

as already said best to replace the whole unit.dont over tighten it when fitting as can easily crack it. check the link as this is what you need .

http://www.ebay.co.uk/itm/Thermostat-Housing-Switch-FOR-Ford-KA-2003-2008-1-3-Duratec-/330870933812?pt=UK_CarsParts_Vehicles_CarParts_SM&fits=Model%3AKa&hash=item4d0971c934

Thanks for your advise guys...took the housing off and soon found that the grove that the seal sits in has broken up in parts letting the seal fall inside,

Seems the plastic Ford use in the cooling sys is very poor...has a simular prob with the electric heater valve some months ago...just disintergrated,

Ordered a new housing from the ebay link...just hope that aftermarket parts are better than the Ford item.

Nick.

its not so much the plastic its the heat that causes the problem

same on most cars. it gets brittle with age and heat. if it was made of steel or alloy it would be worse as

the water with the antifreez in it would cause more problems ie a lot of corrosion.

atleast it's a easy fix m8

Going back a bit I know.

I fitted a new housing back in 2013...started to leak again a few weeks ago...ordered another new housing...took off the old one todat and found the O ring and housing still in good order.

Where I think the leak is from is from corrosion on the flat mounting face where the stat housing bolts on not letting the O ring fully seat.

I dont remember seeing this when I had it off a few years ago.

If I just fit the new housing I think it will still leak as the O ring has nowhere to seat properly.

Any suggestions guys....I was thinking of seating it on RTV silicon sealant to bridge the gap...the corrosion is about !mm deep at worse.

This engine has always had the correct Ford antifreeze as well from new.

Nick.

clean as mush of the corrosion off and try a new 0 ring. you can also try tyhe silicone method you mentioned but you need the proper silicone to do it

not the usual stuff fom b&q.

see link as this is the stuff you may need but it needs a tight seal as the housing is pressurized

http://www.halfords.com/motoring/paints-body-repairs/head-gasket-exhaust-repairs/loctite-5699-premium-silicone-grey-gasket-maker-sealant

Thanks for that Delboy...unfortunately I used the RTV silicon stuff I already had yesterday....but if it fail I will try the stuff in your link.

Its a new one on me but looks good stuff...thanks again.

Nick.

A rubber O-ring seal shouldnt have any need for extra sealant if it has been fitted correctly. If the surfaces are clean and flat your O-ring seal will be fine. Also did you torque the bolts holding the housing to the specified torque?

The problem is that the mating surface is not flat...is has some pitting from corrosion...hence why the O ring failed to seal...but I do agree with what you say.

Nick.

keep us posted nick as it maybe handy to know the silicone you used if its a good fix

Will do...upto now its still water tight.

Nick.