Been getting quite a worrying coolant leak over the past couple of weeks on my Panda 100hp (noticed because I used to own an MG ZR - a car that makes you live in fear on every journey of HG failure).
I've had a really good poke around to try and trace the leak and I think it's coming from the thermostat housing area, although its odd as it only seems to appear just under this area.
Anyhow, cheapest option going forward is to replace the thermostat to begin with and see if that helps... just a couple of questions:
1) Looking online for a replacement, there appears to be quite a few different types, I've tried using my reg no etc to verify the exact part but it still provides me with options... anyone have a link to a direct replacement part that will be of good quality.
2) Does the thermostat come with a new gasket (assume there is a gasket there as it's metal on metal join), if not, where do you get one of those from - am I best going direct to Fiat?)
3) Are there any guides on doing it? It's in a right fiddly place to get to with all the looms etc around it, just wondered if there's an obvious method that I 'm not seeing or is it just going to be annoying, and is there anything to look out for when refilling coolant? The ZR was a royal PITA to drain/refill because of constant airlocks.
4) Am I better off just sticking it in a garage for them to do?

Advice always appreciated. Cheers.

Depends where you buy it from but most supply a gasket although the cheaper ones are normally paper. I have fitted two both haven't leaked. Original are metal.


Be careful if buying from eBay. Some of the images show the wrong part. Missing a small pipe.


Get the Haynes manual from the library. If you are mechanically minded its not too difficult.

Here's a screenprint of the procedure from the Panda eLearn cd:


(click it twice to get the full size)

It mentions removing a gasket but doesn't show an illustration.

Shop4parts would be a great place to buy a thermostat from, all the parts I've bought from them are either genuine Fiat or quality alternative brands.

The thermostat housing comes with a rubber type gasket fitted and you need to get an oem one as they come with metal pipe unions instead of the plastic one as standard which is probably what's leaking, it's quite an easy job but you'll need to remove the battery and battery tray to make things easier to get to.
Turn on the ignition and switch the whole heating system to off, disconnect and remove the battery and tray then remove the coolant filler cap (make sure you've got at least a couple of litres of fresh coolant to refill) put some rags or cloths all around the thermostat area and then simply unbolt the thermostat and let the coolant run out, undo the various connections and replace with the new thermostat housing (have a couple of small jubilee clips handy to replace the snap fit ones that can't be re-used) then bolt the housing back on to the cylinder head or bolt it on then refit all the pipes and the temp sensor plug whichever you find easier, refit and reconnect the battery then fill the expansion tank to the top and start the engine and let it tick over while topping up the expansion tank, switch the heater back on and set to the highest setting with the fan on low and continue to let the engine run with the top of the expansion tank off and top up the coolant giving all the hoses a squeeze to force any air out until it settles at the max mark then refit the expansion tank cap and leave the engine running until you can feel the bottom hose get hot and the heater is nice and hot inside the car, leave it running for a while checking for any leaks and when it's all nice and hot switch it off, go and have a cup of tea and let it cool down before checking the coolant level again and taking it for a test drive.

i never removed the battery or tray? i bought a birth thermostat off ebay. done the job fine.

i did mine in the dark one evening. wasnt too bad. just make sure that the first hose you remove is the small clip on one that feeds the top of the expansion tank, mine snapped quite easily and i had to improvise.

as above, i would also suggest replacing all the clips with decent jubilee clips. the old clips cannot be reused unless you spend ages trying to straighten them.

i had no problem bleeding the system. just filled it up, run the car up to temp and rechecked the level in the morning.

Cheers for all the info, very useful, not sure when I'll get round to doing it, hopefully this weekend, but I'll follow up and give feedback on how I get on with it.

Regarding the thermostat, far too many knock offs out there, go OEM and get one from a main dealer. Thermostat with gasket will be less than £30 all in from previous experience

Most Easterly Pandas said:

Regarding the thermostat, far too many knock offs out there, go OEM and get one from a main dealer. Thermostat with gasket will be less than £30 all in from previous experience

Click to expand...

I opted for a Wahler thermostat supplied by Eurocarparts, it has the metal pipes on, I hope it includes the gasket too, was around £30 mark, due to collect this weekend. Cheers

This was the offending broken thermostat - it was indeed the cheap plastic pipe that had cracked and was leaking, by the time I had wiggled the pipe off of it, it had completely snapped. All replaced now with a shiny proper metal one, thoguht it was all ok but noticed it losing coolant again, I think (I hope) it was just the jubilee clip on the outlet pipe to the radiator that wasn't tight enough as it's that pipe which is leaking. Removed it, replaced with a new clip and tightened, shall see if that stops it...
It did note there was no gasket on the old thermostat, and none with the new one either, just a rubber 'seal' which I suppose does the job.

rubber seal is the gasket. that is all that is needed

Just done this today, used this from ebay, has all steel construction.

https://www.ebay.co.uk/itm/FIAT-DOBLO-PUNTO-500-QUBO-MITO-IDEA-LINEA-PANDA-BRAVO-THERMOSTAT-HOUSING-5520216/251939617723

My old one had split on the plastic pipe, looked to be the original as all the clips were single use ones, so remember to have some new jubilee clips ready before you start.

So thermostat has a rubber 'o-ring' seal (see thermostat pic attached), but there is also a gasket against the cylinder head (see engine diagram for a FIRE engine, not 100hp admittedly but its the same).

The gasket is Fiat part number 55193766

Everyone above only mentions the rubber seal that comes on the Genuine Fiat thermostat... but nothing about the gasket... even the eLearn just says "...restore the underlying gasket."

Is this a replace only if necessary gasket?

I'm pretty sure there was no gasket (only O-ring) when I did mine last year.

gr J

Phone the guys at Shop 4 Parts. They know their stuff and they do not sell rubbish. 01274 734082
https://www.shop4parts.co.uk/?name=contact

They have genuine FCA for £30.
https://www.shop4parts.co.uk/?name=store&op=Product&ProdID=8263

DaveMcT said:

They have genuine FCA for £30.

Click to expand...

If it were me, I'd try to find one with a metal spigot, instead of the stupid plastic one that usually disintegrates after a few years in service.

jrkitching said:

If it were me, I'd try to find one with a metal spigot, instead of the stupid plastic one that usually disintegrates after a few years in service.

Click to expand...

agreed


normally I would go OEM (original equipment manufacturer) or as close to original as possible.

I guess they are plastic on purpose as they also house the temperature sensor which will be affected by the heatsink effect.

Last time I looked, several years ago there was a third type where the housing was plastic but the spigot that breaks was in metal. If they are still available this would be my preferred option

When you are referring to the plastic spigot ? Do you mean the heater pipe (into the firewall) ?

I had trouble with the "quick coupling" on the pipe to the coolant reservoir tank. The one that fits onto the circled pipe attached.

Mine broke. Couldn't find a "quick coupling" alone but could find a hose with the pipe included for a different fiat that uses the same thermostat...

Unless anyone knows a source of the fittings/alternatives?

except for the lockdown. By far the easiest way would be the breakers.

jrkitching said:

If it were me, I'd try to find one with a metal spigot, instead of the stupid plastic one that usually disintegrates after a few years in service.

Click to expand...

The other option from S4P might have the metal spigot. It's worth a phone call.

strange Fiat didn't cast the plastic bit as part of the main housing its only a Hose clamp so wouldn't need any machining.

they went out of there way and cost more to add the plastic bit by drilling, facing and tapping operation

Probably plastic for some marginal performance reason which I don't see myself. Although the lupo and Vectra both suffer with the same design feature


it certainly would bother me to use an alternative metal one and would be the way I would go