The only thing I would add to that is remove the temp sensor from the old stat while it is still attached to the engine.

Also, when checking the coolant level after a few days, remove the cap. Sometimes the level will only drop when the cap is removed.

 

Thank you, will amend accordingly.

 

Nice clear pictures.:

 

Taken on a Nokia N95 mobile phone!
Only set on 2 megapixels as apposed to the full five to help keep the file size down.
Helps it was sunny too

 

Well done, even came up in Google Great idea, thanks for adding

 

I always thought the stat was meant to be an akward thing to do doesn't look too bad there.

 

I have sausage fingers and managed ok!

It just looks complicated with all the different pipes. Chance of cross connecting is virtually zero.

 

Job might have a bang off that then so.

 

Just wanted to thank MPH for this guide.

I changed my stat last night as temps were dropping to 70ºC or below on the motorway. I only had a little run but it seems much better. Temp dropped lower than I would have hoped at 60-70mph though. Had been led to believe that it would glue to 90ºC with the new stat but it seems to drop down to maybe 3/4 or 4/5 of the way between the 50 and 90 marks, which are really non-linear so no idea what that means. 80ºC? 85ºC? I think the system is still bleeding though as I was able to put in 400ml more coolant this morning. Where is it all going? Hope not out the bottom!

Doing 500miles this weekend so should get a proper feel for how quickly it warms up which was a major problem before and what the high speed temperatures are doing. I hope it solves the problem!

P.S. my top tip for removing the Alfa jubilee clips which are a right pain in the ass without the right tools would be to get a screwdriver and a hammer and chisel them off. Wish I had thought of that earlier would have saved me faffing around with hopelessly inadequate plier/cutter things and numerous minor injuries. Italians must have tiny hands!

Also I have a CF2 engine and the air hoses were much further to the right of the engine bay compared to the guide so I was able to (just about) get away without disconnecting them.

Cheers! Dave

 

Update: It took a couple of runs for the level to settle nicely and I guess bleed out all the air. Now it sits on the max, the temp dial starts to move up the gauge towards 50 within a mile or so from cold and will mostly sit a couple of degrees below 90 whatever I am up to apart from sitting in traffic.

As a bonus it looks like my mpg has gained 2-3 too which is quite a nice added extra. I would definitely recommend doing this if you see your temps drop below 80 at speed!

 

The only thing that I would add, is that the pictures are from a plastic cover topped engine (cf2 ?).
I have to change my thermo on the 155 (cf1), and there are 6 pipes going to the housing.

 

Ok, managed to change the thermo today.
Doesn't take long - about an hour.

As I said above there are 2 additional pipes on the earlier engines.
They connect to E + F in the picture, and I had to remove them after I had taken the thermostat off the engine.
I managed to get to both the bolts holding the housing on to the engine using a long reach 13mm socket

 

Nice one Celadon.

Thanks for adding the pics:thumbs:

 

What perfect timing i was just searching for 'how to' as i'm doing mine this weekend!

Thanks MPH

 

No probs:thumbs:

Good luck and use lots of patience.

 

Has anyone made photos of this work in a 1.9 JTD 16V, it would be very useful!

 

Well, i used this guide to do mine today, absolutely faultless a complete success, well done that man for a very useful How To.

One little point i would say is check engine face after removing the Thermostat as i found mine was pitted and damaged somewhat, to overcome this i smeared Instant Seal (liquid gasket) over the part where it bolts to the engine, my new stat came with a gasket but it would never have sealed due to the pitting on the mating surface. Have now driven it and tested it all for leaks etc all is well 90 degrees constant.

I am a happy chap

 

nice writeup and good, clear pictures

i have to do this job on my MGTF over the next few evenings (mines failed), its a much more difficult job than doing the alfas would appear to be but i can take some of your pointers on board whilst doing mine

 

Very good guide, good pictures and clear instructions- well done.:thumbs:

The only thing I might suggest is after filling the coolant up, go and have tea or coffee. The level should have dropped as gravity bleeds the system.

Also, whilst running the engine, run it at 2000-2500rpm to help it bleed. Periodically check to make sure the heater hoses are warming up nicely, and at a faster rate than the radiator top hose (at the radiator not thermostat). This gives early warning on coolant non-circulation before things become damagingly hot.

That is also a tried and trusted technique to check whether the thermostat is weak. If the radiator hose warms up at the same rate as the coolant hoses, the thermostat is weak.

 

is the same procedure for the 1.9jtd 147?

 

It will be similar. The JTD has different piping on the stat so will prob be different sizes clips and looks a bit different.

Not sure where it is on a JTD, but same basic procedure should apply. Remove hoses, remove thermostat, install thermostat, put on hoses and refill. Bleeding should be similar too.

 

Top guide, this. After my garage said it didn't need doing I did it myself. Not hard to do and the joy I felt at seeing my engine run up to 90, then drop when the thermostat opened; I'm ashamed to admit, was almost sexual.

Would say to keep checking your coolant level for a good few weeks afterwards as I've just noticed a month after doing it it's dropped a fair bit on where it was about a week after doing the job.

 

Just replaced thermostat only to read this thread afterwards....
One thought would be 13mm (3/8 drive) socket and small extension to remove the housing as it is really tight for space on the JTS.

 

Ta for the extra info MAZ24:thumbs:

Was it much different on a JTS?

 

No Probs MPH
Near enough the same..Maybe an idea to remove the engine cover aswell to give a little more access. The MAF is located above the air filter housing on the JTS,but every thing else is the same..will sort ya some pics out tomoz (of the finished job ofcourse) for a comparison..

 

Have just changed a thermostat on the V6.
Forgot to take pictures but I shall try to summarise:


Remove induction piping.

Unscrew black electrical box that sits over the thermostat(screws are under the wires inside the box).

Remove the one and only coolant hose.

Go and change your wet shoes.

Remove the 3 bolts holding the Thermostat in and remove the stat(no wires or temp senders involved).

Clean off mating face, install new seal then reassemble with new thermostat.

Refill coolant and bleed/top up as required!

 

Hi Fellas!

Just a curious question on bleeding the system!? My thermostat is the same as celadon's as mine is a 1997 2.0TS 16v Spider. i have been reading around and have understood that i should just remove the lower hose from the radiator and empty coolant mix into a bucket as i recently(Nov 08) had the water pump replaced along with cambelt So!.. i was told to use the same coolant!? Anyways...Is it necessary to raise the front of the car of the ground when bleeding the system and is there a plastic bleed valve on the radiator or am i confusing it with the 156? Zulu ferret recommends raising the front end but! i do not understand why?

The reason why i ask is that i currently do not have access to a trolley jack nor axle stands and was curious...if i could do this thermostat change with all four wheels on the ground?

PS: Thanks for the How To:

kARMA