Erm, allow all day, make sure your knuckles are made of titanium, and for the sake of a few quid, don't be stingy and reuse any of the seals. It's not a fun job, but if a monkey like me can manage, I'm sure anyone else can! If all goes well, you'll spend more time taking the car to bits to get at the thing than you will actually changing the stat itself....

 

Hmm... titanium knuckles... I should really invest in some of those!
I've got a new gasket and the thermostat came with a rubber seal around the edge, plus a manifold gasket too, have I missed any?
Yeah I had a feeling it might be something like that, always the way eh?
Cheers

 

Are you taking the inlet manifold off to get at it then? Will make access much easier when it's off.... Whether or not it takes more time to do that than it saves is anyone's guess! ;-)

 

Taking off the inlet manifold makes things a shedload easier but it's also more work. Either way you'll want everything from a "toy" 1/4" socket set for the thermostat housing bolts upto normal tools for the metal pipe round the back of the engine.

If it's the plastic TC housing try to take it off complete with the metal pipe. If you dislodge the junction between the two you'll need to replace the "O" ring seal. Use a dollup of lithium grease to help the seal along if replaced. This also applies to the rubber pipes. Makes it much easier to get things apart the next time.

Make sure that the replacement thermostat has a built in vent or drill a ~2mm hole in the baseplate level with the two support struts. It'll make the bleeding of the system soo much easier and won't affect the correct operation of the 'stat.

Did this job on the GTi a while ago and had to take off the airfilter assembley and the throttle body to stand a chance.

 

I advise using a quality 8mm 'hex' shape socket on the bolt through the dip stick and not the 12 sided ones to avoid rounding them, same with the 10mm bolts on the back coolant pipe.

I leave the manifold on, but its personally preference.

As said the O rings can perish or deshape, they are £1 each new from Xpart so worth buying.
Also the back metal pipe is very prone to rusting on k-series, I had to buy a new one when fitting my VVC to my 1.1 carb, that was £35 new from Xpart. Didn't want to risk and coolant leaks and posible HGF.

 

Not certain if it's plastic or metal... 1994 carb? (Damp liner K-Series) either way we're planning to keep the housing in as few bits as possible!
Yeah manifold and carb are both to come off.

Thanks for the vent tip! I'll check as soon as I next have the 'stat in front of me

 

Okay, I have a pretty comprehensive socket set kicking around, so at least I have the right kit! (for a change!)
I know it sounds stupid but which pipe exactly? (I haven't seen inside a K-Series yet, so I'm not totally familiar!) Really hope it's in good nic as I don't really have a spare £35!

 

The pipe runs across the back of the engine from the thermostat housing and then round the side of the block to just below the heater takeoff pipe on the head where it jons the rubber pipe from the radiator. It is held by two bolts to the block. I took mine off during the HGF work in the autumn as it looked very scabby and I was suspicious of it. Give it a really good going over with the palm sander and it seemed sound under the scale (No deep pits or pinholes) so I gave it several coats of black smoothrite (Smooth hammerite) for protection.

I'll echo Metromartins comments on sockets: Always use hex ones and if possible the type that drive on the flats. I have a set of these from 10 to 22mm at 1mm increments, even if the bolt heads or nuts have rusted down a size or two, they can often get a grip. Particularly useful on exhaust manifolds.

 

If you do take the inlet manifold off it would be a good opportunity to fit a Viton inlet manifold gasket.

If you leave the manifold in situ (not something I'd do personally), don't lean on it

 

Thanks, I'll have a good look at it for anything obvious... But I may be inclined not to touch it if I don't have to :/ but if it looks knackered I'll do something about it!
Wow, decent set!

Yup, manifold is coming off!! And why a Viton gasket specifically? (I can only seem to find them for 1400's, but I'm guessing they're the same?)

 

Do you know, I didn't even spot this was the Metro / 100 section :lol:

I assumed (wrongly) you were asking about the 1.4 / 1.6 / 1.8 k series and their plastic manifolds. I'm not sure what the set up is on your car; do you have the same plastic manifold fitted as per the bigger motors? If so, the Viton gasket is the latest version of that rubber inlet manifold gasket. It's a bit more pricey (around £20) but I haven't had any leaks since fitting it to mine. *runs off to find some wood to touch*

 

Aren't the placcy inlet manifolds fitted to the MPi models?

 

Yup. As far as I know. The rest get alloy ones that use the paper type of gasket and are less prone to leaks. I just used the rubber (or whatever it's made of) gasket that was in the kit of parts for a top overhaul when I did the head job last year. Mind you I did dollup a load of extra silicon sealer around the two water gallery points where it joins the head. Belt and braces!

 

Aha! So that's why I couldn't find one!
Yup, silicone sealant at the ready.

 

Thermostat replacement went almost perfectly!! Thanks for all the help guys, made a big difference to the job