We have an R reg 1.2 Mk1 Punto which seems to either have an engine temperature problem, or the gauge isn't reading properly.

Even after many miles of motorway driving the temperature gauge hardly moves. In addition to this it seems to be fairly heavy on fuel - with the plugs showing as quite black and sooty, as if the mixture is too rich.

Is it possible that their is a thermostat problem so that the ECU thinks that the engine is cold, and the mixture set accordingly, or is this just likely to be two different problems - with the temp gauge just simply not working for some reasons or other.

Any advice/suggestions would be very much appreciated.

newbieboy said:

Is it possible that their is a thermostat problem so that the ECU thinks that the engine is cold, and the mixture set accordingly, or is this just likely to be two different problems - with the temp gauge just simply not working for some reasons or other.

Any advice/suggestions would be very much appreciated.

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Hello - yes, definitely. I reckon your diagnosis is spot-on. My Punto had an 'emergency' with overheating about six months ago (I've only had it for a week so I'm going on the receipts in the service history). Anyway the fault turned out to be simply the temperature gauge earth. What I'm suggesting is that if there is a gauge fault, perhaps it would read high like mine did, rather than low.

Your symptoms point to cold running so I would buy a new thermostat and fit it as soon as you can. I think it's a simple job with just two bolts holding the thermostat onto the cylinder head - go carefully though and use plenty of CRC/WD40 just in case they've seized - you don't want to shear them off. I reckon a thin smear of gasket sealant is worthwhile even with a new gasket - if you don't have a new gasket, clean the flanges well with wet 400-grit sandpaper or similar and use the sealant (try to get a new gasket though!)

The price of the thermostat will be quickly repaid by the fuel saving and also the heater will work a lot better, which is probably very important for you at this time of year (it's almost 30 degrees here so I'm just guessing... )

Cheers,
-Alex

The mk1 temp gauge on is an odd thing so define barely moving, mine rarely reaches above the bottom mark on it on cold days with the heater on i've never seen half in normal conditions only sitting in traffic in the sun and a quarter being normal running temp in warmer times or after 95 for a while, if it doesn't climb while sitting stationary with the heater off then its probably shafted.

Thanks for that excellent reply, Alex, I'll get a new thermostat and give it a try.

ps You're right about the weather here. 30 degrees over there is it, you lucky sod!

Thanks for the reply, Steven. There is hardly any discernible movement on the gauge, it clearly isn't working as it should. I will change the thermostat first and see what happens before I delve into the gauge itself.

I must come clean on this. I haven't actually looked at the problems on this Punto - it is my son's car and, as he is almost 200 miles away, I'm trying to advise him over the phone.

I passed on the info about the thermostat, and when he took off the housing to check it he said it looked as if the thermostat was missing. Now he's had the car just a couple of months, and this problem has been there since he had it, so could it have run this time without a thermostat?

I think that it would explain the symptons - slow to warm up and higher fuel consumption. Does this make sense?

newbieboy said:

I passed on the info about the thermostat, and when he took off the housing to check it he said it looked as if the thermostat was missing. Now he's had the car just a couple of months, and this problem has been there since he had it, so could it have run this time without a thermostat?

I think that it would explain the symptons - slow to warm up and higher fuel consumption. Does this make sense?

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Oh yes - it certainly does.
There are quite a lot of people out there from a Hillman-Imp era who seem to think that removing the thermostat is a perfectly good way to solve any overheating problem. It's useful in rare cases where the thermostat sticks closed during a journey, but generally speaking, the cooling capacity of the radiator far exceeds the requirement for daily driving, and so without the thermostat, you end up running too cold.

-Alex

Thanks again for that. He is going to fit a new thermostat at the weekend. If that doesn't cure things, I'll report back.

Cheers

Just a quick update:

New thermostat fitted over the weekend, and the problem solved - the engine warms up nicely and runs a lot better.
There was also a connection problem between the sensor and the temperature gauge - fixing that has got the gauge working as well.

Splendid! I love a happy ending..

Ralf S.

hi first time on here.. i have a couple problems i have punto turbo mk1, i was driving and changed from 3rd to 4th and the rev counter bounced and i lost power. the car starts and drives ok under 2500rpm anything above when the turbo kicks in the car splutters and backfires no power? plus i have now found my temp gauge isnt working at all not reading nothing?? any ideas please thanks luke

lukey25 said:

hi first time on here.. i have a couple problems i have punto turbo mk1, i was driving and changed from 3rd to 4th and the rev counter bounced and i lost power. the car starts and drives ok under 2500rpm anything above when the turbo kicks in the car splutters and backfires no power? plus i have now found my temp gauge isnt working at all not reading nothing?? any ideas please thanks luke

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try your air flow meter and change thermostat as my old gt3 was doin the same it was lyk bukaroo try the conection 1st as it may be corroded if so just clean with wd40 and connect and disconnect it a few times and try it

ive tried doing that to the connection and still nothing i changed the plugs this morning took it round the block and is still backfiring at boost. the plugs i took out were whitey/brown. could it be fuel pump not working properly?

Sort the back firing before you blow the manifold then worry about temp g/g.