Thermostat housing removal

[jammacdo]

Guys

How the **** to you remove the third bolt (hidden from view next to the engine block) that holds the thermostat housing onto the water pump?

I spent hours yesterday trying various methods.

I've removed the exhaust manifold (seems to help a bit)
The water pipe is free of the housing rubber pipe (boy was that on tight)


Its a pig of a job, easily worse that front clam or anything else I've done on the car. There is NO room, everything is zip tied to each other. Its a freaking nightmare.

Think I'm going to have to remove the inlet manifold (and there are some difficult bolts I can see.)

Any tips?

I need to remove the thermostat as I think its faulty and stuck closed.

Thanks

James

[Shug]

The car is built round that thermostat (assuming you're talking K series?) I think selection of wobbly extensions or remove inlet manifold is the way.

Take the opportunity to replace it with a blank and stick a PRT (pressure relief thermostat) kit in a more accessible place. Available from Eliseparts and all the usual elise aftermarket folks.

[jammacdo]

Thanks Shug

I have the PRT kit ready to go...if and when I ever make way for it.
Its tricky to get off even compared to my crappy old Mini that I used to swear at. Think I'll just go straight to inlet manifold removal, cant see me getting to the hidden bolt now.

What a **** design!!!!

[jammacdo]

And in true "panic lets ask for SE help" I then have a think and realise I don't need to remove the third (or any) of the three bolts holding the thermostat housing cover on. Just removed the dipstick bolt and manhandled the bast*** off. Whew, really didn't want to remove the inlet manifold or I'd end up buying an uprated one "whilst I was there" Did however utilise the new "inspection hatch" I now have in the boot.

Cheers and onwards with the installation. Makes a mockery of the instructions time estimate though.

[robin]

Have you tested your thermostat yet? Before you go changing all the pipe work, it would make sense to confirm the stat is faulty .... because if it isn't then you have another fault somewhere else, and switching to PRT won't fix that (it will just make it harder to diagnose, as the PRT operation is more complex).

Cheers,
Robin

[jammacdo]

Yes, will boil up some thermostat for breakfast

[jammacdo]

Boiled the thermostat in some water today. Had to boil it really well before it even thought about opening. Did eventually open but probably right around the 100c mark when loads of bubbles showing. Nowhere near the 87c its supposed to start opening at. Would explain why I have managed on just 2 occasions recently observed the return side of the radiator getting hot. Clearly a combination of cooling by heater matrix, cold ambient temperature/air cooling and reluctant thermostat have been why I've seen no coolant being circulated.

[robin]

The trick is to boil the water for long enough to get the stat right open. Leave a thermometer in the water. Turn off the heat. Watch the stat close and the thermometer. When the stat is just completely closed, that's the regulation temperature.

Cheers,
Robin

[robin]

P.S. Remember that the stat is the only thing in the system that will regulate the temperature to a specific level ... all other components of the cooling system can lose heat (or not, as the case may be) but none can regulate to a specific temperature ... so if the temperature on your dash is stable under load, your stat really must be doing something, at least that's what I think .... perhaps I am wrong.

Cheers,
Robin

[jammacdo]

The trick is to boil the water for long enough to get the stat right open. Leave a thermometer in the water. Turn off the heat. Watch the stat close and the thermometer. When the stat is just completely closed, that's the regulation temperature.

Cheers,
Robin

Brilliant, thanks. Was happy that it opened at all. Will try that out.

[jammacdo]

Have run the engine up to temperature and it all works.

Used my home made pressurisation cap on the expansion tank to do the initial bleed. Good to know that the water now circulates and radiator comes up to temperature properly. Which is doubly good because I have a remote sensor for the fan, which also now operates properly.

Not been on the road yet but it all looks way better than before. Think the 5 years the car stood in the garage seized the thermostat to the point it wouldn't budge afterwards.

It was a lot of work, faffing with stupid hoses and pipes but hopefully its going to all work now.