HELP, where is the water temperature sensor on my punto mk 2 HLX 1.2 16v? i cant't find it it's driving me insane .

thanks carl.

carlmarcantonio said:

HELP, where is the water temperature sensor on my punto mk 2 HLX 1.2 16v? i cant't find it it's driving me insane .

thanks carl.

Click to expand...

Hope this helps

ziggy

thanks Ziggy, i think i've found it now, but is it in the most awkward place in the world to get to, with all the other engine managment, coil pack gubbin around it? does anyone have any instructions for removal and refit

Find the lowest Radiator Water Pipe (usually bottom of the rad btw)
And Remove - Let the water gush out
Once drained - simply make access to the sensor
as you said the coil Packs might need to move
Removing the battery May be a good idea too
undo old sensor
Refit new sensor
Refit Rad Hose Bottom
Refit any other parts remove
Refill with a good 50/50 Mix of water and antifreeze
Bleed the system
problem solved

had todo it on my 8v, as the seal had sprung a Mould patch = Leaking slowly

Ziggy

thanks for those instructions the battery coil pack etc, i was hoping there was another way around it...just being lazy! i presume the sensor is the same for bothe the 8v and 16v.

cheers Carl.

aghh there's three 11mm bolts holding the sensor on!! the one at the back is seriously imposible to get to...why FIAT!

If this sensor has a defect, could it cause misfire and lag of power then the engine is cold?

shans said:

If this sensor has a defect, could it cause misfire and lag of power then the engine is cold?

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potentially

If the sensor gives a false reading - it could be making the mixture to lean or too rich for the current conditions

Which may result in lack of power and missing

For example

If the sensor was saying hot, when it was cold
the mixture would be too lean = Weak bang = Lack of power

If the sensor was saying the engine was cold, when it was infact too hot
the engine will be running rich, as it thinks it needs to warm up
As a result the mixture is possibly drowning the spark plugs with fuel = missing
And potential bore washing = lack of lubrication = lack of compression

See the issues now?

ziggy

Yep! You support my own theory Ziggy. I have had problems with our Punto, but especially when it is cold weather/ winther time. I know plugs, leads, coil are ok and i have just changed the generator and battery. My next guess was the temperature sensor. When the engine is warmed up after a few miles, it runs perfect, regardles of the weather.

shans said:

Yep! You support my own theory Ziggy. I have had problems with our Punto, but especially when it is cold weather/ winther time. I know plugs, leads, coil are ok and i have just changed the generator and battery. My next guess was the temperature sensor. When the engine is warmed up after a few miles, it runs perfect, regardles of the weather.

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hmmmmm
that doesn't sound sensor like to me....

But there cheap here (£5 if you have the unscrew type)

i'd be tempted todo a compression test to see what the compression is cold

Ziggy

Ziggy122 said:

hmmmmm
that doesn't sound sensor like to me....

But there cheap here (£5 if you have the unscrew type)

i'd be tempted todo a compression test to see what the compression is cold

Ziggy

Click to expand...

Okay???
Please giv me some ideas then. Why would you think "bad" compression?
I mean, the car starts right away and pulls nicely when warm. If the ignition is in "top dollar" condition, the only thing left, is a Petrol issue.

Rough running at low temperatures can be an early sign of HG issue. Alternatively, how old are the plug leads? Reliable life of OE ones is about 4 years. Some of the cheapo replacement ones less than that.

fingers99 said:

Rough running at low temperatures can be an early sign of HG issue. Alternatively, how old are the plug leads? Reliable life of OE ones is about 4 years. Some of the cheapo replacement ones less than that.

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HG=head gasket?
No had that one changed a year a go.
The rough running is ONLY when it is cold weather and when the engine is COLD. When the engine is warm, no problems.

Plugs are new and leads is approx. 3 years. Both from NGK. The car has had the problem each time we reach winther time for the last Four years. This year it is just realy bad.

You can test the sensor resistance while it is still on the car.

at 0C 5.97K ohms
at 10C 3.81K ohms
at 20C 2.5K ohms
at 40C 1.15K ohms
at 50C 0.8K ohms
at 60C 0.57K ohms
at 80C 0.30K ohms
at 90C 0.24K ohms
at 100C 0.17K ohms

Thanks Judderbar!
I will try that first, but it will have to wait till the weekend.
I will get back with an up date.

/ Søren

Well time for an up date. I never got to test the commpression.
I spoke to a FIAT mecanic and he said " Søren the 1,2 16v is hyper sensitive if the plugs and leads are not original FIAT parts. And when you change the plugs, the threads on the plugs, has to be absolutly clean! You must ONLY tighten he plugs with 1,8 kg/ 17,5 Newton! NO more than that!!"

So I did what he told me to do and the car runs perfectly now!??
The "old" plugs and leads was from NGK but that was not good enough!

shans said:

Well time for an up date. I never got to test the commpression.
I spoke to a FIAT mecanic and he said " Søren the 1,2 16v is hyper sensitive if the plugs and leads are not original FIAT parts. And when you change the plugs, the threads on the plugs, has to be absolutly clean! You must ONLY tighten he plugs with 1,8 kg/ 17,5 Newton! NO more than that!!"

So I did what he told me to do and the car runs perfectly now!??
The "old" plugs and leads was from NGK but that was not good enough!

Click to expand...

Nice to see you got a good result

I found yesterday that the 'astoundingly' low torques on these cars was even less on my car because my wrench has to be set to 14nm to give me 10nm. Which then explains why my perfectly running car had spark plugs that could be more or less undone just using the extension reaching down to the plug without the handle on it