Help- Car overheated how do I remove thermostat?

[Nev]

Hope someone can help.

On the way to work today the Caterham overheated. I stopped and allowed it to cool and topped it up , not much coolant lost ( through expansion cap pressure release value) and although the top hose was hot the bottom one was completely cold, and I mean cold! Basically no circulation. As I was less tha 1/2 mile from work I managed to get in OK. But I would like to try and sort or at least diagnose the cause before using it again.

Given that the car has been running for several months since it last had its coolant changed I do not suspect an airlock.

However it may be a water pump or stuck thermostat.

 

So can anyone give me an idea how easy it is to remove the themostat , I was going to remove and see if that fixes it as a first step this afternoon ( so I can drive it home ) ?

Any other ideas welcome.

I hope to try and have a go at this after lunch today, so if anyone can help or has any photos of the thermostat housing that would help.

Engine is 1.6K standard EU3.

Thanks

Nev

[Stef]

Oh dear Nev, thats a good way to spoil a nice start to the day!

 

I'm about to install a thermostat into a car that has never had one so would also appreciate any links to photos.

[Team Escargot]

Nev

Stat is tucked away under the plenum (induction) towards the front of the engine. The rear top hose (large J shaped) connects on to it.

 

There are 3 cap head bolts holding the plastic stat housing together (Allen key required) – very fiddly to get to.

 

First: drain the rad - undo the bottom hose clip from the rad and pull off hose carefully and drain into container.

 

Undo J hose from stat housing and remove

 

Undo the 3 Allen key cap screws and remove

 

Gently pull off plastic stat cover

 

Stat then can be removed

 

Check stat temp (stamped on it – could be 82 or 84 deg C)

 

Check stat operation by placing in nearly boiling water (increase temp until stat opens) if you have a thermometer so much the better.

 

When reffiting dont overtighten the cap screws!

 

If not working replace – if working OK then it could be a head gasket job or the fan is not working (check fan first!)

 

If engine is OK (ie not blown head gasket) I would advise fitting a remote stat such as QED – if a lot better and kinder to the engine.

 

Hope this helps

 

Blat me if you need to discuss on the phone

 

Nick

 

[Nev]

Would I be correct in the following.

To remove the thermostat I need to remove the thermostat housing and then seperate it (unbolt) and then remove the stat, reassemble and refit the housing.

And,

to remove the housing I need to remove the J hoses and the then unbolt the housing from the engine block.

Has anyone done this? and if so how easy is it to do with the engine in situ?

 

Nev

[Nev]

Thanks Nick, that doesn't sound too bad, and is roughly what I had pieced together from the internet, only more precise

I think (hope) the problem is definetely a circulation problem as the bottom hose ( large one from Rad) was cold ( ie not even luke warm) to the touch. Hopefully this overheating has not cause any damage to the Head ☹️

I shall give it a go later.

Thanks agian.

Nev

[Adrian Williams]

Nev

 

I don't envy you trying to do this in the car park at work ☹️

 

I'd leave the J hose attached to the stat housing and remove as a unit once the J hose has been removed from the submarine.

 

Good luck

 

 

Adrian

[Nev]

Phew ! Job done.

Bit of a fiddle (need smaller hands).

Thanks everyone, Nick notes where spot on, with the exception that the housing bolts where 8mm bolts in my case not allan.

So Stat removed, I took the rubber seal from around the stat and inserted this back into the housing recess so that it has a seal and all seem well again. Bottom hose is now getting warm. Just need to do a bit more bleeding and should be good to drive home .

Also checked the stat in a cup of boiling water and it did not budge at all, so good confimation that it was indeed the stat.

Off to order a new one now .

Thanks again everyone.

Nev

[Team Escargot]

Nev

Glad to hear your on the move again.

Nick

[grumpy the 7th]

Nev. I was told the following...........

 

Always use a GENUINE Rover rubber gasket and best to use Lockheed gasket grease.

 

And

drill a 1/8 dia hole in the stat plate. This helps with filling the system and also slightly "warms" the bottom half of the engine so when the stat does open the hot water doesn't "shock" the lowwer half of the engine.

 

And

replace the bolts for Allen headed bolts and don't over tighten.

 

rog

[Stef]

Can anyone tell me the best place to get the rubber gasket or o ring and what size or part no I am asking for. Caterham say they foot sell them.

 

Thanks

[Stationary M25 Traveller]

Try Redline Components 01883 346515

[Sheds Moderator]

Local motor factor, they sell a kit with a stat, gasket, O rings etc for the relevant Rover car the engine was intended for.