General Overheating issue

[Sigourney]

Hello, I was wondering if I can get some help please before I loose my head.
Fiat 500 2013
Error message "excessive radiator fluid temp" after around 5/10 minutes of driving. Drops right down if I put the heating on and put the windows down (if I am unable to pull over)
Thermostat was changed around 12 months ago, coolant level is fine and isn't dropping (so no sign of a leak) fan kicks in as normal. Has been checked for airlocks.
Any other ideas please.
Thank you.

 

[Sigourney]

New radiator a couple of hundred pounds for a decent one- depends if you or someone you know can fit it rather than a garage, which would add a couple of hundred more to the bill!.

Ok, not as expensive as what I thought actually.

 

[Sigourney]

DIsconnect the rad hoses. Flush with LOTS of clean water from a hose. Block the bottom, fill up and drain repeatedly then use a flushing agent. Try not to disturb the quick release fitting on the bottom hose though. Cut the hose clip and refit with a new one. The quick release fitting comes only with a new hose. Dont buy from Fiat they are over 10X the price of gates hoses on eBay. The temp sensor is part of the thermostat and could be the problem. If you buy an Original Birth thermostat from Shop4PArts these have the metal pipe fittings and an excellent waranty. Check the cooling fan is working too.

Thank you so much for this. Definitely going to flush the radiator and change the thermostat. Really hoping that's all it needs. I changed the thermostat for similar symptoms last year but also because my heating stopped working but it's still working this time which is handy because turning that on has been bringing the temp right down for me (I know I shouldn't be driving it) haha

 

[AnthonyH]

I think its the water pump.

I'm guessing its original to the car and the timing belt could do with changing as well.

Deffo worth putting on a new thermostat first, and flushing the radiator as they're cheap.

A new water pump and timing belt is setting you back £400.

 

[Sigourney]

I think its the water pump.

I'm guessing its original to the car and the timing belt could do with changing as well.

Deffo worth putting on a new thermostat first, and flushing the radiator as they're cheap.

A new water pump and timing belt is setting you back £400.

Really hoping its the thermostat!! Thermostat is ordered and going to pick up some *radiator cleaner* not sure of the proper name. Any recommendations for the cleaner at all? Thanks

 

[The Panda Nut]

Thank you so much for this. Definitely going to flush the radiator and change the thermostat. Really hoping that's all it needs. I changed the thermostat for similar symptoms last year but also because my heating stopped working but it's still working this time which is handy because turning that on has been bringing the temp right down for me (I know I shouldn't be driving it) haha

When refilling I find these are a pain. I have had to refill and refill upto 10 times after bleeding. I actually blow into the top of the radiator to force water into the system untill the air stops coming out of the bleed screw. Someone on here has suggested a way of using a raise header to fill the rad. If I can find it I will post a link but I am not too good at this bit. Meke sure the radiator fins are OK and air is going through the rad and the air con condenser (if fitted). Turning on the heater having an good cooling effect suggest the rad is the culprit to me. Its just not removing the heat enough.

Water pumps should be changed as part of any cambelt job. A proper kit would include one. HAve a rummage on the service history. Belts are aroudn £30 and kits around £110 if parts are quoted,

 

[PuntoHowTo]

Next time it happens put your hand on the top radiator hose, it should be hot, if not then it’s likely the thermostat is stuck shut.

If hot then it’s possibly a problem with the radiator being blocked or possibly a head gasket issue

 

[Sigourney]

When refilling I find these are a pain. I have had to refill and refill upto 10 times after bleeding. I actually blow into the top of the radiator to force water into the system untill the air stops coming out of the bleed screw. Someone on here has suggested a way of using a raise header to fill the rad. If I can find it I will post a link but I am not too good at this bit. Meke sure the radiator fins are OK and air is going through the rad and the air con condenser (if fitted). Turning on the heater having an good cooling effect suggest the rad is the culprit to me. Its just not removing the heat enough.

Yes I agree, in regard to the heating situation, Im presuming having the heating on is pulling the heat into the car and so it's bringing the temp down because the radiator isn't doing what it should. Let's hope it's need a good flushing out. My 500 is an absolute work horse and iv been very lucky with her to be honest. So hoping she isn't about to let me down.

When refilling I find these are a pain. I have had to refill and refill upto 10 times after bleeding. I actually blow into the top of the radiator to force water into the system untill the air stops coming out of the bleed screw. Someone on here has suggested a way of using a raise header to fill the rad. If I can find it I will post a link but I am not too good at this bit. Meke sure the radiator fins are OK and air is going through the rad and the air con condenser (if fitted). Turning on the heater having an good cooling effect suggest the rad is the culprit to me. Its just not removing the heat enough.

Water pumps should be changed as part of any cambelt job. A proper kit would include one. HAve a rummage on the service history. Belts are aroudn £30 and kits around £110 if parts are quoted,

 

[The Panda Nut]

Next time it happens put your hand on the top radiator hose, it should be hot, if not then it’s likely the thermostat is stuck shut.

If hot then it’s possibly a problem with the radiator being blocked or possibly a head gasket issue

Stuck open?

 

[Sigourney]

Next time it happens put your hand on the top radiator hose, it should be hot, if not then it’s likely the thermostat is stuck shut.

If hot then it’s possibly a problem with the radiator being blocked or possibly a head gasket issue

If I'm honest as soon as I pop the bonnet, the heat is insane. Hard to say where it's coming from but I will definitely check the radiator hose next time.
Praying it's not head gasket (sounds expensive) Thank you.

 

[varesecrazy]

Stuck open?

No.... Open would let coolant to the Radiator

 

[varesecrazy]

@Sigourney
Does the coolant level hold, even in your 5 minute overheat scenarios..?

 

[Greasytrucker]

Yes I agree, in regard to the heating situation, Im presuming having the heating on is pulling the heat into the car and so it's bringing the temp down because the radiator isn't doing what it should. Let's hope it's need a good flushing out. My 500 is an absolute work horse and iv been very lucky with her to be honest. So hoping she isn't about to let me down.

To me the way turning the heater on brings the temperature down indicates it’s a radiator issue as the heater matrix is essentially a mini radiator so you’re just increasing the cooling capacity by using the heater. Hopefully a good flush will make a difference

 

[Sigourney]

@Sigourney
Does the coolant level hold, even in your 5 minute overheat scenarios..?

If I'm honest it's very hard to see where the coolant line is! But I know it has recently been topped up and I can see where it is when I take the cap off. But today after the overheating message again when I took the cap off, loads of coolant spilled over the top as well as lots of steam. I then wondered if there was too much coolant but even after loosing some it's happened again 30 minutes later. Hope that makes sense.

 

[The Panda Nut]

WHen the car is cold remove the radiator cap. Start the engine and run it till its warm. Head gaskets usually allow gas into the coolant if they blow and you can see if the fluid is heavily charged with gas bubbles, You should be able to see if the water pump is running as the fluid level should drop a little when revved. On the Panda if the bleed valve is open / removed revving the engine sees a real fountain from the pressure of the water pump. You will have to re bleed after this though. Gas in the coolant will also result in the hoses being very hard when the engine is warm. You should expect 20psi but that is squashable with a gloved hand. If the water level isnt dropping regularly the head is probably OK. Plugging into MES will tell you if its hotter than it should be so also worth doing in case the gauge has gome AWOL.

 

[Sigourney]

To me the way turning the heater on brings the temperature down indicates it’s a radiator issue as the heater matrix is essentially a mini radiator so you’re just increasing the cooling capacity by using the heater. Hopefully a good flush will make a difference

Thank you for that. Heating on full blast and having the windows down does bring the temperature down instantly.

 

[varesecrazy]

If I'm honest it's very hard to see where the coolant line is! But I know it has recently been topped up and I can see where it is when I take the cap off. But today after the overheating message again when I took the cap off, loads of coolant spilled over the top as well as lots of steam. I then wondered if there was too much coolant but even after loosing some it's happened again 30 minutes later. Hope that makes sense.

That's a common complaint..

Shine a torch down the outside..

You will see the fluid, and where it stops

 

[AnthonyH]

If I'm honest as soon as I pop the bonnet, the heat is insane. Hard to say where it's coming from but I will definitely check the radiator hose next time.
Praying it's not head gasket (sounds expensive) Thank you.

If you carry on driving it like this then you'll give the car a head gasket problem (assuming it doesn't already have one). A new head gasket is £600-800.

 

[PuntoHowTo]

Thank you for that. Heating on full blast and having the windows down does bring the temperature down instantly.

The way fiat configures there cars is that the engine and the cabin heater always have coolant circulating even if the engines is cold. So when the thermostat does open it routes the coolant to the radiator only.

If you can bring the temperature of the engine down by running the interior fan on full heat, it does suggest there may be more of an issue with the thermostat but that’s not guaranteed.

A few years back there was a constant problem with the mk2 Punto as there was a bad batch of thermostats floating about that was causing cars to over heat, people would replace the thermostat and it would still over heat.

It’s quite possible your new thermostat is bad, it’s always worth making sure you get the best quality stat you can afford

 

[Sigourney]

The way fiat configures there cars is that the engine and the cabin heater always have coolant circulating even if the engines is cold. So when the thermostat does open it routes the coolant to the radiator only.

If you can bring the temperature of the engine down by running the interior fan on full heat, it does suggest there may be more of an issue with the thermostat but that’s not guaranteed.

A few years back there was a constant problem with the mk2 Punto as there was a bad batch of thermostats floating about that was causing cars to over heat, people would replace the thermostat and it would still over heat.

It’s quite possible your new thermostat is bad, it’s always worth making sure you get the best quality stat you can afford

Thank you for that, I did unfortunately just go for a cheaper stat, so maybe that's why it has only lasted 12 months. Bur cheaper enough to change every year I guess. Here's hoping it's just the thermostat that needs replacing

 

[Sigourney]

If you carry on driving it like this then you'll give the car a head gasket problem (assuming it doesn't already have one). A new head gasket is £600-800.

I won't be driving the car now until my new thermostat arrives. Haven't really known what the problem was and what problems it can cause the car. But now I have an idea of what it is thanks to all that have helped I won't be driving it now until iv tried all the suggested things. Fingers crossed I haven't caused more damage.