Hi there,

This is my first thread on the fiat forum and I will apologise profusely for the length of this post but I need to explain exactly what happened to my car.

Right, here we go.

I recently brought a 2003 ('03) punto mk2 b 1.2 8v, when I drove it about a 40 mile trip, the engine warning light came on, the temperature gauge dropped to the bottom and the fan was running for ages after the engine was switched off. I let it cool down and started the return trip home. The engine warning light was still on but it still drove fine and the temperature gauge worked fine as well. Just as I got near my home, the temperature gauge dropped back down and the fan came on and was on for ages again after I switched the engine off.

I had it put on a scanner and was told it was the coolant temperature sensor. I changed it 2 weeks ago and it has been fine until Sunday when I did 250 miles and the temperature gauge was going up and down like a navy's pick and the engine warning light came on. I left it to cool for an hour and went back to it and the temperature gauge worked fine and the engine warning light went out.

I then did another 40 mile trip and the temperature gauge dropped down and the engine warning light came on but the fan didn't. I again left it to cool down and started the trip home again. When I come to start the car it struggled to start as if lack of fuel. Once it started, it drove home fine with the engine warning light on. When I got about 2 miles from my house the temperature gauge dropped down and the fan started to run.

The top hose was warm (you could easily grab it, even after that 40 mile trip), the heater was not as warm as it usually got (one of the reasons why I brought the car in the first place) and there was very little pressure inside. I also checked the usual signs for the head gasket but it's fine.

Can someone point me to the right direction with what they think is wrong with my car.

Thanks for taking the time to read my thread and I hope you can guide me in the right direction. (I am used to working on classic cars not modern cars with electronics).

yes mate and welcome to the forum
you have classic air pocket in front of the thermostat
system needs a proper bleed
did it possibly have a headgasket or radiator etc before you bought it?

Faulty thermostat.
or Mass air lock, my Guess,

have you tried bleeding the coolant, Rad first?


edit, sandb got in first,

Thanks for the help, over the weekend I bleed the system.

I took it for a approximate 10 m

10 mile trip and the warning light went out again.

But if you leave it to idle for ages, the gauge goes up to half way and stays there, but when you drive it approximately 1/4 mile, the gauge drops to 1/4 way on the gauge and stays there.

Any help please

Thermostat sticking open, I'd think. I'd guess it takes a good while to warm up, too.

Best bet is a genuine one from FIAT, Shop4Parts, or eurocarcare.net. There are a lot of nasty (probably Chinese) ones out there at the moment.

if you live anywhere bigger than a village then doubtless you will have a motor factor that the local garages use
if you walk into their trade counter they will sell you a complete thermostat by a recognised manufacturer like gates or BG Automotive Ltd
you will get change out of £20 ,buy a jubilee clip at the same time
if done on flat land you wont even need to bleed after fitting
take battery and tray out to help so you have better access
radio code available on this site for a donation if needed afterwards

Just beware of white box stuff or anything that doesn't have a manufacturer's stamp on the stat itself. Facet and Motorad are also good brands.

i've had aftermarket stat's and never been happy

Had a fiat stat - quicker to warm up, hold temperature better, except cold out side, cold inside car, stick heating on 4 HOT, the super cooling effect beats the 1.2 heating ability

Ziggy

Thanks again for your help all, I will go to my local fiat dealer and price one up

I can confirm, it's an easy job and the part is cheap (whether fiat or third party)

Make sure the gasket is included when you buy. You may also want to use blue gasket sealant.

Handy to have a couple of spare screws in case there's been leakage and corrosion of existing screws (this was my experience).

Col Max Pyatnitski said:

I can confirm, it's an easy job and the part is cheap (whether fiat or third party)

Make sure the gasket is included when you buy. You may also want to use blue gasket sealant.

Handy to have a couple of spare screws in case there's been leakage and corrosion of existing screws (this was my experience).

Click to expand...

no gasket in box is a sure sign your buying junk

s and b said:

no gasket in box is a sure sign your buying junk

Click to expand...

I'm sure you're right. I just threw it in as the way the parts are listed on Shop4Parts (who would generally be ok), there's a separate listing for the gasket and for the 'stat:
http://www.shop4parts.co.uk/?name=store&op=Results&category=13&secondary=28&opts=1192
Doesn't mean there isn't one included with the thermostat of course (I didn't order from them in this case, but went bricks-and-mortar local seller). And naturally you might want to replace the gasket at some point so good to be able to order separately.

Also, I'll link my own recent thread here: https://www.fiatforum.com/punto-ii/340156-temperature-variations.html
Some of the same symptoms as the later problem identified here (temp up when idling, down when driving, etc.,), and some tips on where to get new thermostat.

If no gasket - woopy doo
You can make a gasket easily

however its nice having a proper one to start with
Any sealant suitable for cooling system will be fine

I use a locktight Black silicone one
Stick like a bitch tbh... never had a leak from when i've done it

Putty the thermostat - stick seal on - light pressure to make sure contact - and leave to go tacky but not dry
Then layer other side, leave a few mins to go tacky then stick to the cleaned engine face

I brought mine from Ebay - from Partsworld i think, shy under £15 for a genuine fiat stat

Ziggy

I have just ordered the new thermostat off eBay (genuine one, but what torque do I tighten the 10 mm bolts too

They're 6mm IIRC (torque for bolts depends on the thread size, never, ever, the size of socket!).

I looked in the Sei manual -- same stat, same engine, and there is nothing, but 0.8Nm (the zero is important) should be about right.

I don't think anyone uses a torque wrench on them!

crazyimpnut1991 said:

I have just ordered the new thermostat off eBay (genuine one, but what torque do I tighten the 10 mm bolts too

Click to expand...

Not stupidly tight

basically what i do is get them both finger tight (via the socket extension), that should have it flush/sealed

I then apply a little bit of power via ratchet and nip it up
I dont use big ratchets, only small, why?
Less torque, but a good feel

Ziggy

Ziggy122 said:

I dont use big ratchets, only small, why?
Less torque, but a good feel

Ziggy

Click to expand...

And less weight to lug around.

fingers99 said:

And less weight to lug around.

Click to expand...

True - big ratchets
Story goes like this

you stupid son of a B****, why wont you f***** come off, you lumpy piece of s***

Then you realise you put it on tighten - grin - flick switch - magic!

Ziggy

The book says 10Nm which means the special small torque thingy or you're just fooling yourself. Torqued fasteners have their place in high stressed applications like motor moving parts,hub nuts and so on but it's starting to spread like bacteria all over the car - knock sensor bolt, brake bleed screw. Give us a break. Ott imho.
Personally I use feel and the Mk 1 eyeball for parts like this. I've heard too many stories of water pump and stat threads stripped,crossed, not seated flat etc etc all with a torque thing at the back of it all. The can be too long and heavy for proper feel.
Clean the threads, check they all run the same-ish by hand and keep your eye on what's happening. Use the Force