replacing thermostat

[pinstripe pete]

I replaced the fan switch this afternoon - however after running the car up to temperature whilst attempting to bleed, it was clear the fan wasn't going to kick in. (Also have duff temperature sender at the moment) Top of radiator hot, lower pipes cool. From Techtalk this clearly sounds like a dodgy thermostat. Switched off engine.

 

I'll order it this week. My mechanical ability is quite low but I'll attempt to replace the thermostat. I've located it, including two rear facing bolts just beyond where the J pipe attaches, and a bolt which holds the dipstick housing. From the archives it seems a bad idea to remove the J pipe.

 

Simply - how do I best replace the thermostat???!!!! (car is a VVC)

 

PS if anyone has a Bleed Tee for sale or know where I could get one I'd be v. interested!

[F355GTS]

Pete

 

you'll need to drain the coolant and then undo the j pipe at the other end and remove the pipe which will go either to the heater or the water rail.

 

Undo the single bolt which also holds the dipstick, then remove from engine and to replace thermostat undo the the 3 bolts holding the housing together.

 

refit in reverse order

 

Mark

[micksmetafors]

If one half of the engine is hot and the other coldthere is probably an air lock.

 

Add water mix via the heater hoses until the water flows out of the top rad plug hole then there is hardly any air to bleed out.

Normally the fan switch works much more efficiently after bleeding and the heater is more efficient

 

 

[pinstripe pete]

This afternoon I got the front of the car up high - when the old (suspect) fan switch was removed coolant flowed out as expected (therefore no air in radiator?)

 

Millie - if there was an airlock would it not have found its way to the top of the radiator if it was the highest point?

 

'A gentleman is a man who opens the door for his wife to carry the coal in'

[Myles]

Erm,

 

I can't remember having to remove any of the pipes - but I might be mistaken.

 

They are in such a bl**dy awkward place, that ISTR you'd really struggle to get the damned things back on.

 

Anyway - that aside - my tip or recommendation when you've got the thermostat housing off is to carefully relube the rubber o-ring on the thermostat housing where it enters the block (vaseline has been recommended - personally I just used the teeniest smear of Castrol LM...) If you don't do this, you can easily snag the ring and break it... ...less than 50p to get a new one from Rover - but one hell of a PITA

 

The other 'tip' is not to use the Halfrauds thermostat. Nothing wrong with the physical mechanism/item (I've been running one for the last 5-10k), but the gasket/seal that they supply was too large a diameter. I ended up using the old seal with the new thermostat.

 

HTH

 

Keep BC free and open for ALL. Membership No. 43xx

 

Alcester Racing 7's Equipe - 🙆🏻™

 

Alcester-Racing-Sevens.com

[Felix E]

Pete, do check the thermostat when you get it out by suspending it in a kettle of water using string/wire. Bring the kettle to the boil and see if the stat opens (92 deg. or thereabouts) - maybe you won't need a new one.

Some people recommed drilling a small hole in the stat to let water through which stops airlocks forming.

Best Regards,

 

Felix.