Fiat Water Temp Sensor??

[madmurdoch]

Hello there,
Was just wondering if some-one could shed a bit of light on my question please??
I have a Fiat Tipo 1.4 with a 2.0 8v conversion done by myself,
And to be honest i think the Temperature Sensor is playing up !
Can anyone be kind enough to point me in the right direction of obtaining a new one or cross referance would be good...
thank you and Thank you in advance.
Darren.

[Guy Croft]

Unlikely that the sender is faulty, it is such a robust thing, but it could certainly be a mismatch with the gauge if not paired to it ie: compatible.

Get some stick-on temperature strips from Think Automotive in Isleworth and put them on the head to check actual temp.

GC

[Julian]

Just a small hint to those unfamiliar with those strips, the temperature strips only measure the maximum temperature they have been exposed to so if the engine temperature is fluctuating or you are trying to reuse them you will find some very unexpected behaviour.

[Evodelta]

Darren,

Is it possible you can give some more info:

Which sensor (air or water) and what does it send its signal to, guage or ECU?
If it is the one that the ECU uses what type/make/ shape is it? (pic?)

Martin.

[madmurdoch]

Darren,

Is it possible you can give some more info:

Which sensor (air or water) and what does it send its signal to, guage or ECU?
If it is the one that the ECU uses what type/make/ shape is it? (pic?)

Martin.

Hi, Sorry for not being really clear..

The Sensor i have enclosed a photo below,
What is happening is when i start the Car, It runs really bad as if its only firing on 3 Cylinders, It Splutters and will cut-out compleatly if there is no revs, Also back fires....
It does it for around 3-4 Mins then clears itself,
I know this is not a long time but there is an obvious problem somewhere and would like to get to the bottom of it.

[/img]

[Evodelta]

Hello,

These sensors are notorious for failing and causing problems, quite often by fooling the ECU and making it run the engine rich (black sooty smoke from the exhaust), probably because people fit cheap copies generally found on internet auction sites and the like (which is also a great place for, ahum, borrowing pictures......)
Bear in mind it could also be the air temp sensor that is at fault.
Because the Ford Cosworths run a similar Magnet Marreli EMS they use the same sensors, this widens the availability because Fiat have quite stupidly stopped stocking it.

What you have there in your pic is (probably a copy of) a Magnet Marelli WTS09, which is a short nose (but otherwise identical) version of the WTS05, before condemning yours you can test it for correct electrical resistance using a multimeter set to 'Ohms' at the following temps:

Temp 'C ------- Resistance
0 ------- 9.75
10 ------- 5.97
25 - ------- 3
30 -------- 2.42
40 --------- 1.60
50 ---------- 1.08
60 ---------- .75
70 ----------- .53
80 ----------- .38
90 ----------- .28
100 ------------ .15

The air temp sensor can be tested using the same values. You must test this at the ECU pin outs as this will check for faulty wiring at the same time.

Originals can be ordered here:

http://www.mmcompsys.com/

I think they are about ‚£22 ea and there is a minimum order of maybe ‚£50 before VAT. (This last sentence is a bit vague as it has been a long day, is late and my memory is failing me).

Hope this helps.

Martin.

P.S. The above is from the perspective of an integrale owner - i.e. You may find what you have is slightly different, but the principle is the same.

[SteveNZ]

The Weber-Marelli coolant temperature sensors fail often. The Bosch ones are better. You may have either depending on the injection system.

These sensors look very similar and can be physically interchangeable but you must use the correct type for the injection system.

[Guy Croft]

Well done indeed for getting to heart of the issue members!

I must admit that it never occured to me that the sensor in question was anything other than the gauge sender!

GC

[Infectus-Guy]

On my old 1.6 HF turbo, i had shocking running problems and it turned out to be the temp sensor. I tried the boil in a pan and meter trick and the resistance actually went up as the temp went up. This meant it fueled even more as the engine got warmer!!! I was too tight/couldn't be bothered to find a new one so i found out the warm and cold resistance and wired up two resistors with a switch. So when the car was warmed up i just flicked the switch to the normal running temp resistance! I later sourced a second hand sensor which did the trick, but i was still rather proud of my over technical bodge!
Guy

[Evodelta]

My car still has the original sensor in it - it's thirteen years old.

I think they may be Jaeger.

[madmurdoch]

Thanks for all your replies on this Subject, Really helpful
But does anyone think it would be the Temp Sensor causing the engine to
run really bad as if its only firing on 3 Cylinders,
It Splutters and will cut-out compleatly if there is no revs, Also back fires....
It does it for around 3-4 Mins then clears itself,
I know this is not a long time but there is an obvious problem somewhere and would like to get to the bottom of it.

[Infectus-Guy]

Thanks for all your replies on this Subject, Really helpful
But does anyone think it would be the Temp Sensor causing the engine to
run really bad as if its only firing on 3 Cylinders,
It Splutters and will cut-out compleatly if there is no revs, Also back fires....
It does it for around 3-4 Mins then clears itself,
I know this is not a long time but there is an obvious problem somewhere and would like to get to the bottom of it.

That sounds JUST like what my HF turbo did, clouds of blue smoke out of the back, running on a couple of cylinders etc. It would sometimes misfire so badly that the dashboard would violently shake to the point where i thought it was going to end up on my lap. Also worth checking your dissy cap though, i found mine full of water once from where the top hose had split and sprayed it all up inside! But seriously, you NEED to make your temp sensor the first port off call having checked all the easy obvious ones (Leads, plugs, dissy etc.)
Guy

[madmurdoch]

Thanks for all your replies on this Subject, Really helpful
But does anyone think it would be the Temp Sensor causing the engine to
run really bad as if its only firing on 3 Cylinders,
It Splutters and will cut-out compleatly if there is no revs, Also back fires....
It does it for around 3-4 Mins then clears itself,
I know this is not a long time but there is an obvious problem somewhere and would like to get to the bottom of it.

That sounds JUST like what my HF turbo did, clouds of blue smoke out of the back, running on a couple of cylinders etc. It would sometimes misfire so badly that the dashboard would violently shake to the point where I thought it was going to end up on my lap. Also worth checking your dissy cap though, I found mine full of water once from where the top hose had split and sprayed it all up inside! But seriously, you NEED to make your temp sensor the first port off call having checked all the easy obvious ones (Leads, plugs, dissy etc.)
Guy

Thanks Guy,
Ive Checked all the obvious things,
Will try and get a water temp sensor and see if
the problem persists...