What Happened:
Drove for 20-30 mins with the engine too hot light on (ignorance, don’t hate me)
Large quantity of steam released into engine
Coolant leaked underneath car
Radiator appears to be cool, fan appears to be functioning properly

Attached is photo of working thermostat, as well as photos of how mine has broken.

I want to know if the initial overheating is likely to have been caused by the thermostat breaking, or if this break is as a result of the large amount of pressure built up inside the engine from another issue.

2011 1.2 panda, engine code 169A4000

Hello and welcome to the forum.

Are you saying that the thermostat housing has actually been blown off the engine?

This is most unusual and would certainly represent an extreme case of overheating. I've quite often seen the housing gasket fail (and that can lead to quite a dramatic spray of coolant all over the engine bay), but never actually seen the housing blown off the block.

It could be caused by a failed thermostat. That said, in the event of a serious overpressure siuation, I'd have expected the coolant cap to release it, or some other part of the cooling system to fail before the housing.

What is the current status of your car?

photo 1) looks to be over the gearbox
photo 2) looks to be the thermostat
photo 3) looks to be just to the right of the injector plug. This is the position of the temperature sensor

These are plastic and degrade over time other parts of plastic have failed mainly on the 1.4 engine. It is the First I have seen fail. 30 minutes is a long time ? Putting that much heat into it isn't Good for the plastic also.


As long as the coolant and oil look okay and don't smell of petrol

I don't think you have any choice except replace and test. Fingers crossed

If all goes well you will have to change the oil if it has genuinely overheated.

jrkitching said:

Hello and welcome to the forum.

Are you saying that the thermostat housing has actually been blown off the engine?

This is most unusual and would certainly represent an extreme case of overheating. I've quite often seen the housing gasket fail (and that can lead to quite a dramatic spray of coolant all over the engine bay), but never actually seen the housing blown off the block.

It could be caused by a failed thermostat. That said, in the event of a serious overpressure siuation, I'd have expected the coolant cap to release it, or some other part of the cooling system to fail before the housing.

What is the current status of your car?

Click to expand...

photos with the red on are at the back of the engine. Temperature sensor location ???

there will be a lot of steam. Boiling water hitting the red hot exhaust. The Good news there must have been some coolant left.

Has it accurately broken off or has the pipe fallen off ?

koalar said:

there will be a lot of steam. Boiling water hitting the red hot exhaust. The Good news there must have been some coolant left.

Has it accurately broken off or has the pipe fallen off ?

Click to expand...

attached is a photo of a new thermostat, the black plastic mounting tube has cracked off cleanly, staying within the tubing

jrkitching said:

Hello and welcome to the forum.

Are you saying that the thermostat housing has actually been blown off the engine?

This is most unusual and would certainly represent an extreme case of overheating. I've quite often seen the housing gasket fail (and that can lead to quite a dramatic spray of coolant all over the engine bay), but never actually seen the housing blown off the block.

It could be caused by a failed thermostat. That said, in the event of a serious overpressure siuation, I'd have expected the coolant cap to release it, or some other part of the cooling system to fail before the housing.

What is the current status of your car?

Click to expand...

no the thermostat is still connected. main housing is still very solid, would be very scary if that blew off. The black plastic spigot(?) has cracked off cleanly, staying within the pipe that was attached.

koalar said:

there will be a lot of steam. Boiling water hitting the red hot exhaust. The Good news there must have been some coolant left.

Has it accurately broken off or has the pipe fallen off ?

Click to expand...

accurately broken

lucP said:

attached is a photo of a new thermostat, the black plastic mounting tube has cracked off cleanly, staying within the tubing

Click to expand...

thats normal falure for a 1.4 engine

I didn't know they were fitted to 169 1.2 engine ??


its on the right hand side under the coil packs not the back by the injector ?

koalar said:

photos with the red on are at the back of the engine. Temperature sensor location ???

Click to expand...

I have now taken the battery & mounting out so here is my thermostat, you can see the clean break of the spigot(?) Any advice for how to remove the electric plug & the radiator hose would be much appreciated as they seem impossible well attached.

jrkitching said:

Hello and welcome to the forum.

Are you saying that the thermostat housing has actually been blown off the engine?

This is most unusual and would certainly represent an extreme case of overheating. I've quite often seen the housing gasket fail (and that can lead to quite a dramatic spray of coolant all over the engine bay), but never actually seen the housing blown off the block.

It could be caused by a failed thermostat. That said, in the event of a serious overpressure siuation, I'd have expected the coolant cap to release it, or some other part of the cooling system to fail before the housing.

What is the current status of your car?

Click to expand...

My car runs fine as long as I take breaks to cool down the engine

lucP said:

no the thermostat is still connected. main housing is still very solid, would be very scary if that blew off. The black plastic spigot(?) has cracked off cleanly, staying within the pipe that was attached.

Click to expand...

Ok that makes sense now.

koalar said:

I didn't know they were fitted to 169 1.2 engine ??

Click to expand...

Fitted to the Euro5 and later; it's the same arrangement as the 1.2 500.

Euro4 and earlier Pandas have a different housing and thermostat, without the temperature sensor - which is what threw me off track initially. My bad, the OP had already posted the engine code, which is correct for the Euro5 engine.

These housings with the plastic spigot are notorious for failing; it's poor design and a big step backwards from the previous housing, despite being about four times the price of the old one. I believe some aftermarket replacements have metal spigots; get one of these if you can to avoid a repetition of the problem at some future date.

Mind you, the earlier engine has a flimsy steel pipe in the cooling circuit which is also notorious for failing and taking out the HG.

lucP said:

My car runs fine as long as I take breaks to cool down the engine

Click to expand...

I'd caution you in the strongest possible terms not to try to run the engine again until it's been repaired and filled with fresh coolant.

The 1.2, whilst generally bulletproof, is notorious for head gasket failure following overheating. Often by the time the red over temperature light comes on, the gasket is toast.

From what you've posted so far, I'd be very surprised if the engine hasn't been damaged, but I'll keep my fingers crossed for you.

Once it's repaired and back in service, keep a very close eye on the coolant level for the first week or two.

These are low coolant engines. Any loss of coolant will almost always destroy the head gasket, but when you do a proper job, the plastic inlet manifold gets damaged.

I can't remember but the majority of electrical connects on the panda require a little lug to be pushed down before you can pulling them apart.


It might be easier to see to undo if you unbolt the housing from the head first

some of the third party housing have a metal spigot instead of plastic so will never be a problem again.

I believe someone found just a replacement brass spigot a few years ago. Probably not worth the effort though as the problem of getting the plastic one out. And you might as well replace the thermostat at the same time

cheers jrkitching I wasn't aware the later engines had a change of design

koalar said:

I can't remember but the majority of electrical connects on the panda require a little lug to be pushed down before you can pulling them apart.


It might be easier to see to undo if you unbolt the housing from the head first

some of the third party housing have a metal spigot instead of plastic so will never be a problem again.

I believe someone found just a replacement brass spigot a few years ago. Probably not worth the effort though as the problem of getting the plastic one out. And you might as well replace the thermostat at the same time

Click to expand...

Just want to say I replaced the thermostat, got some jubilee clips to attach the tubes again after mangling the horrific stock clips they had on there. Filled with just water to check if no leaks + if all running well and it looks good to me! Very glad i chose to try and fix this myself, cost me £40 all in.

I'm going to uni in october so won't be driving much so didn't bother to spend the extra on a metal spigot as didnt seem worth it. Hopefully it behaves itself now.

Now it's time to find the cause of the horrifically stiff gearbox...

Thank you so much everyone for the advice, I'll write up a guide with photos and attach it here in case anyone does run into this again .

jrkitching said:

The 1.2, whilst generally bulletproof, is notorious for head gasket failure following overheating. Often by the time the red over temperature light comes on, the gasket is toast.

From what you've posted so far, I'd be very surprised if the engine hasn't been damaged, but I'll keep my fingers crossed for you.

Once it's repaired and back in service, keep a very close eye on the coolant level for the first week or two.

Click to expand...

I will do exactly this. Should i bother checking the head gasket just while I'm in the middle of having everything open? I've no idea how I'd start to go about that. It seems to be staying perfectly @ temperature now, which I'm very glad for.

lucP said:

Just want to say I replaced the thermostat, got some jubilee clips to attach the tubes again after mangling the horrific stock clips they had on there. Filled with just water to check if no leaks + if all running well and it looks good to me! Very glad i chose to try and fix this myself, cost me £40 all in.

I'm going to uni in october so won't be driving much so didn't bother to spend the extra on a metal spigot as didnt seem worth it. Hopefully it behaves itself now.

Now it's time to find the cause of the horrifically stiff gearbox...

Thank you so much everyone for the advice, I'll write up a guide with photos and attach it here in case anyone does run into this again .

Click to expand...

gear selector cables are common. You can try cleaning them up with something like methes. Gearbox end. Pull each lever to expose the cable.


Oil normally works.


grease is a big no no. works fine to start with. After about a week you will be bake to square one and hard to clean off

lucP said:

Now it's time to find the cause of the horrifically stiff gearbox...

Click to expand...

Try changing gear with the car stationary and the engine switched off.

Is it stiff all the time, or only when the engine is running.

This will help you to differentiate between a clutch problem (quite likely the hydraulics rather than the clutch itself) and a problem with the selector cables or the 'box itself.

lucP said:

It seems to be staying perfectly @ temperature now, which I'm very glad for.

Click to expand...

Get some proper coolant in ASAP; the aluminium radiator will be quickly damaged if you leave plain water in there, and then you'll have another leak and another problem.

Some say even leaving the radiator empty but wet for 48hrs is enough to cause significant corrosion damage; the advice if storing one is to dry it internally using compressed air (or whatever; hairdryer perhaps?) before putting it away.