Changing Thermostat (2.4 petrol)

[stuart bowes]

re: changing the thermostat..

Is there some reason I can't work out for why they say drain 2lts of coolant before you start? far as I can see that's just an easy way to add a massive air bubble into the system..

correct me if im wrong (quite likely) but surely if I just undo the thermostat housing and immediately hold that pipe upright, losing a minor amount of liquid in the process, I can get someone to hold it upright while I put the new 'stat in, and then reconnect it, again losing some small amount of liquid..

ok it makes a bit of a puddle but wouldn't it mean less air trapped in the system and i can just top up whatever small amount is required

probably a stupid question for reasons i haven't considered yet


also, re: the temperature sensor, how likely is that to be failed? bascially im getting a really slow warm up time. when it does get to temp it blows nice hot air, it just takes ages. and driving along it dips back below the middle so im guessing stat stuck open. The reason i suspected the sensor was that I got warmish air coming out at halfway to warm (1/4 of scale)

[VOLVOBOY]

Hi.
Changing the thermosat is not the "Just Job" that it seems.
You will end up cursing the pipe and the person holding it for being "in the way".
It`s just as easy to let a couple of litres out from the Rad drain tap.
Either way you burp the system by pouring the coolant SLOWLY into the expansion bottle whilst squeezing and releasing the top hose.That will remove 95% of the air. Run the engine up to temp and cool down. Top-up to finish.
Doesn`t sound like there`s anything wrong with the temp sensor. Just the Stat not closing or stuck open as you say.

[stuart bowes]

Yeah I get what you're saying, fair enough

I suppose i'll just not be so lazy and go get the washing up bowl. sure the missus wont mind it smelling slightly of coolant no I can probably find something else

stat first then and see how it goes

better than stuck shut I guess

ta

[oragex]

As above, lookup on yotube before starting, and most likely you won't be able to undo the entire housing unless the intake manifold is out. Small mention, not tried myself but it appears the thermostat for the diesel engine will fit inside the housing of the petrol ones, at a much cheaper price than replacing the entire housing. As for draining the coolant, the reservoir needs be emptied - by all means disconnect the electrical connector for the level sensor before lifting the reservoir. You also have some fluid inside the big hose at the thermostat, so that's another lost fluid. Be sure to position the thermostat inside with the small burping pin at 12 o'clock and you need to reaseal the housing, I used Permatex for coolant systems

[stuart bowes]

Cheers I'll order up some sealant, good call

I always check youtube first before doing anything lol I swear if there was one for putting pants on in the morning I'd probably check I was doing it right

there's no mention of removing the manifold to do the replacement, apparently it's just the top part of the cam cover. I only need to unbolt the top half of the housing to swap the stat and put it all back together unless I've missed something along the way

have replaced various thermostats in my time I just find myself being a bit more cautious with this car a) because it was expensive and b) because it has this curious habit of chucking up faults on the DIM for seemingly unrelated systems

[oragex]

Only from 2003-UP The manifold needs to come one only when removing the entire tstat housing altogether - without splitting it open. Some people reported having tools to undo the whole housing without touching the manifold, but I don't believe everyone has them at hand. The torx bolts to split it open may be a little stuck, I like to keep down pressure on them while rotating gently

[Georgeandkira]

Diesel? I'm confused.
Your 2001 will have the same plain elbow my '02 had if it's petrol. Easiest t-stat change in the world.
Housings came later on.

How many miles on your '01?

[oragex]

Well seen. I didn't notice OP had a 2001

[oragex]

Originally Posted by stuart bowes

Cheers I'll order up some sealant, good call

I always check youtube first before doing anything lol I swear if there was one for putting pants on in the morning I'd probably check I was doing it right

there's no mention of removing the manifold to do the replacement, apparently it's just the top part of the cam cover. I only need to unbolt the top half of the housing to swap the stat and put it all back together unless I've missed something along the way

have replaced various thermostats in my time I just find myself being a bit more cautious with this car a) because it was expensive and b) because it has this curious habit of chucking up faults on the DIM for seemingly unrelated systems

Forget what I said. Your 2001 has a simple to replace thermostat.

[stuart bowes]

Originally Posted by Georgeandkira

How many miles

Just shy of 56k . (aka delivery mileage lol)

also.. oh good thanks for clearing that up I was a bit confused as well, it looked so easy in the video