General Punto 188 underheating

[SebastianBerko]

Hi guys,

I recently bought my third Punto (ELX 16v Speedgear) and I’m having a little issue with it.
When the engine is put to work, acceleration, driving uphill or in town driving etc, the car reaches working temperature as normal, but when on the motorway and going downhill, ie the engine is not doing much and air cools the radiator, the temperature gauge fall substantially - just as if I had just turned in the car, about halfway between working temperature and ‘cold’.

Am I right I’m suspecting a thermostat change is imminent or am I completely off my trolley?

Thanks in advance,

Sebastian

 

[multipete]

Yes,thermostat opening too long.

 

[SebastianBerko]

Thanks, I’ll need to sort that next weekend then. Didn’t want to spend a Saturday evening changing the thermostat only to find out there is some sort 3-way mixer valve I didn’t know about.

Thanks for the response, I’ll update once sorted in case future people might benefit from it..

 

[mackai]

I had a similar issue a couple of years back. Would get up to temp but any driving dropped my temp down to halfway between cold and ideal. Changed out the thermostat and everything was fine after.

 

[Ziggy122]

Stats gone lazy.... buy quality parts (fiat / gates etc)



Ive had trouble with QH stats....

Bleeding the air is a bitch

Ziggy

 

[Scudmonkey]

Quick and easy job to replace stat......PITA to bleed the cooling system after

 

[dumbledore]

I would test thermostat first. If the car warms up fast then the thermostat may not be the issue here. The ECU and temperature sensor have issues. Do you get management light on by any chance?

 

[SebastianBerko]

Dumbledore: That’s exactly what I was thinking and why I created the threat. Anyroad, no, no engine management (or other warning light) has come on at any point.

 

[dumbledore]

As I said if the car warms up quick about 3 miles to the quarter of temperature sensor indicator then thermostat may be OK (not stack open). You can also test it by feeling the hoses in the engine when you start the engine from cold.
My car shows symptoms like yours after a long drive when I not loading the engine. The gauge starts drooping and if the outside temperature is below 13 degrees eventually the gauge will suddenly drop to zero and if it stays there without recovering more then 15 seconds the engine management light will turn on. The car will still drive OK after this though. At the moment is still OK but once it will get colder I will get the problem for sure. Yesterday just managed to survive it as it did not stay at zero long enough before I applied some load to allow the engine warm up just a bit to stop triggering the engine management light. I changed the temperature sensor, done all the grounds cleaning but problem is still there. In my case I can't see the thermostat to be the problem, I can only assume there is some issue with the ECU but as the car is working fine, fans long ago disconnected and blades immobilized (as the bearing make noise on the move, blades turning from wind) there is no issue driving with eml light on. The light goes off after 3 or 4 starts that have not triggered the sensor problem. So wait for the weather to turn colder and see how the car behaves.

 

[SebastianBerko]

Dumbledore: That was sort of my concern. When the thermostat goes I suppose they usually stay either completely shut or open - but this goes up and down depending on the load put on the engine. But well, in a hilly fairly warm climate I suppose it could go oscillate.
Regarding the outside temperature, well I’m/we’re using the car in Gibraltar/southern Spain so the outside temp rarely drops below say 15 degrees Celsius at the coldest.
Anyroad, as an update, according to my girlfriend, the tempurature gauge also showed overheating earlier today as she drove it, after which she stopped in the hard shoulder, waited a few minutes and then drove on. I have no way of verifying what actually happened other that her explanation, so I’ll have to see if this happens again at some point when I’m driving it. I’ve only experienced it oscillating but below working temperature and cold.
Perhaps both the temperature sensor and the thermostat are both acting up?
Does anyone have the part number for the temp sensor for the 188A5.000?

Thanks guys, the aid thus far has been greatly appreciated!

 

[algeciras92]

I think Thermostat opening

 

[dumbledore]

Actual overheating is serious and you should take care. Coolant check and bleeding the system should be investigated. Check radiator for any leaks. Low coolant levels could contribute to larger then usual fluctuations in the temperature reading.

 

[BILL33]

His punto is UNDERheating not OVERheating.

And yes, the number one to blame is an stuck open thermostat.
Put a new one and its back to normal temp.

 

[SebastianBerko]

Right, so I finally got round to swapping out the thermostat yesterday and it sorted the issue - tempurature is well regulated now.

Thanks for the help guys!