Lancia Motor Club

Model Technical and Interest => Fulvia => Topic started by: andyps on 06 December, 2016, 09:39:29 AM



Title: Thermostat
Post by: andyps on 06 December, 2016, 09:39:29 AM
I need to remove the thermostat from my car to try to ensure that anti-freeze can get into the cooling system fully - the car isn't running at the moment but it will turn over so I figure that if I turn it a bit the anti-freeze will mix with the water already in the system but presumably the thermostat will stop it getting from the radiator to the engine when cold. My question is - is there anything difficult about taking it out, once I locate the thermostat of course!

The other alternative is to drain the water completely but I prefer to leave anti-freeze in a system for protection if possible.

This may all be a waste anyway as the car was stored for 26 years before I got it so I've no idea how good the engine really is but it did run in April when I went to look at the car so worth trying.


Title: Re: Thermostat
Post by: Richard Fridd on 06 December, 2016, 01:50:45 PM
Thermostat is in the water casting, with a fine thread. Casting can fail if corroded, when removing thermostat. The casting could be heated externally to open the thermostat.


Title: Re: Thermostat
Post by: lancialulu on 06 December, 2016, 05:03:26 PM
They are pigs to unscrew especially if it has been in a long time. My method is crude but works but you lose the thermostat. You knock in the centre past and use a small hacksaw blade to cut out a 1/8th of the remaining brass ring down to the thread with care and remove that segment then you can collapse the remaining body and it will undo cleaning the threads as it goes.

It is a good idea to have a high concentrate blue antifreeze to prevent further corrosion occuring in the engine if left empty but wet....


Title: Re: Thermostat
Post by: fay66 on 06 December, 2016, 06:05:30 PM
They are pigs to unscrew especially if it has been in a long time. My method is crude but works but you lose the thermostat. You knock in the centre past and use a small hacksaw blade to cut out a 1/8th of the remaining brass ring down to the thread with care and remove that segment then you can collapse the remaining body and it will undo cleaning the threads as it goes.

It is a good idea to have a high concentrate blue antifreeze to prevent further corrosion occuring in the engine if left empty but wet....
I agree with Tim, I had to use this method, you will probably need to clean the threads, but what hasn't been said is that the thermostat screws into the housing, which is why it's such of a pig to get out.
When you replace the thermostat make sure it has a bleed hole about 1/16" diameter, I had a couple of years of trying to figure out why my 2c kept overheating after replacing the thermostat, but there wasn't a problem when the thermostat was removed, in fact I ran it for two years without a thermostat and using a rad blind in the winter.
There was a bad batch of reproduction thermostats produced in the early 2000's which have been sold as old/new stock, I bought two thinking one was faulty and at about 50 a time it was expensive lesson, eventually figuring out what the problem might be, drilling the hole cured the problem and she's never overheated since.
When you drill the hole you need to screw the thermostat in to determine where to drill the hole.
Brian
8227 8)


Title: Re: Thermostat
Post by: andyps on 06 December, 2016, 07:54:00 PM
Thanks for the replies, may try to get the housing really warm to open the thermostat for now just to circulate the anti-freeze. Might be easier than getting the 'stat out by the sounds of things!

Having not yet done any work on my car, the really daft question is "where is the thermostat"? At least I know where to look and put some heat with that knowledge.


Title: Re: Thermostat
Post by: Richard Fridd on 06 December, 2016, 08:31:04 PM
Where top hose from the radiator meets engine. 


Title: Re: Thermostat
Post by: andyps on 06 December, 2016, 10:00:29 PM
Where top hose from the radiator meets engine. 

Thanks, that is where I would have assumed but good to have it confirmed.

At least the immediate concern has gone as the forecast is 14c tomorrow rather than the -1 we had yesterday!


Title: Re: Thermostat
Post by: nistri on 07 December, 2016, 06:56:10 AM
Another less drastic method to unscrew the thermostat is to remove the housing, place it vertically in a container full of penetrating fluid and also fill the housing with penetrating fluid for one week. Use a 36 mm hexagonal socket to unscrew it. Andrea


Title: Re: Thermostat
Post by: davidwheeler on 07 December, 2016, 10:46:44 AM
Why not just take off the hose at the back?     Removing the stat is fraught with risk!