156 not getting up to temp?

[Vittorio]

Hi Guys
I have had the same problem as bloomers1156 with my 2004 alfa 156 JTS.
So I replaced the thermostat together with the temperature sensor yesterday and after a 30km run I achieved a maximum temperature reading of 70 degrees on my gauge.
Thought I'd run a test on my old thermostat today and I don't know what to make of the readings.
Firstly I put the old thermostat in a pan ,  filled it with water and brought it to the boil.
The results are as follows.
80 degrees  fully closed
90 degrees the bulb moved 1/8"
93 degrees the bulb moved 3/16"
95 degrees the bulb moved 1/4"
97 degrees the bulb moved 5/16"
At this point the temperature inside the housing around the bulb was at a maximum of 97.5 degrees and I could not get it any higher however the water was boiling and the temperature outside the housing was 98.8degrees.
The temperature measurements are accurate but the movement measurements are eyeball only.

From this test I assume that the thermostat is functioning properly and that the temperature sensor is faulty.

Does anyone know whether the engine management system relies on this sensor to calculate the air/fuel ratios or is there another sensor somewhere.

any comments would be welcome

Vitt

[colcol]

The temperature sensor is on the thermostat housing, remove the wire and ground it, the temperature gauge should go to min or max, if it does this, you have the right wire!, remove the temperature sender and give it a clean up as they can get corrosion on it, that insulates it from the real temperature of the coolant, Colin.

[colcol]

I noticed that on the specs for this thermostat, that they should begin to open at 88 centigrade, i would like to know what causes them to fail after omly a few years and to open early, me thinks that they look like a undersize thermostat, Colin.

[bloomers1176]

Well I thought Id update, finally got to fit the part after waiting an ice age for a company in the UK to admit they sent me the wrong part arseholes.

Anyway...... Fitted it after losing those bloody factory fitted alfa hose clamps. (replaced with shiny Jubilee's)

Hour job at max. what a lovely sight seeing for the first time seeing the needle banging on the door of 90! Lovely jubbly.

Running so so much better and oddly enough fault codes have dropped from 3 to 1 losing codes 420 and 430. The cat threshold inefficiency bank  1 and 2 jobbies.

That just leaves code 340 the (Crankshaft position sensor A bank 1 circuit malfunction)

This one was cleared and stayed off a week. then popped up. cleared it again still waiting.

I tried looking for the crankshaft sensor both from above and below and Im buggered if I can see it. certainly no brown connector. Looked near the rear of the starter didn't jump out??? odd.

Anyone know if they are prone to go after 114k?  Have looked for a new one and they all come without cable for mine?? was thinking if its circuit malfunction then with cable may prove better?

Cheers fellas

[colcol]

Usually when the crank sensor goes, it stops when the engine is hot and then works when the motor cools down.
I have replaced the crank sensor in my JTS, not because it failed, but i have bad memories of a Commodore that used to eat crank sensors, so after 12 years and 125k, i replaced it.
I ordered one, the JTS is different to twin sparks, and i was buggered if i could find it as well.
Then i was underneath the car replacing the sump on the engine and i noticed at the back of the crank, near the no 4 conrod, there was a gear like device for triggering the crank sensor, and then i saw the crank sensor.
So you will need to look for the crank sensor from under the car, from memory it is at the front of the engine, held in by a 6mm cap screw, so you need a 5mm allen key, Colin.

[Mick A]

back of the engine under the starter motor.

[Craig_m67]

Typically the crank sensor starts to fail when it gets hot ie. starts fine then gives up about twenty minutes later. Sounds like yours is about to go. It's not repairable, a piece of cake to replace and not very expensive. Swap it out now before it leaves you stranded. Car won't start or run when it does fail.

[bloomers1176]

Cheers fellas...... Yes I suspect that the ole cranky crank sensor maybe lining me up for trouble.

Im not being lazy cause I have searched for many times for the right one. But mine is always advertised without cable? I want a bloody cable with it. As the code mentions circuit malfunction as a side.

Anyone??

2003 156 JTS manual.

Thanks in advance.

Long shot but if anyone has any pics of the location of the crank sensor Id be eternally grateful Id like to have a go myself after the all conquering replacement thermostat. (Im relatively new to the tools).

Cheers.

[Craig_m67]

It's very difficult to photograph as it's on the side of the engine block facing the firewall, underneath the starter motor. The starter motor is on the passenger (LH) end of the engine block, near the gearbox, ie. where the flywheel is. You get to the sensor (6mm Allen bolt) from underneath, you can find it easily by chasing the loom down the back of the engine, there are no other sensors down their (just the starter motor).

You need to to work out which part number you actually have, they may be slightly different across the engine/model range.  Pretty sure mine (JTD) was also just a sensor that you then plugged into the loom, was ages ago that I did it (2008).

Whack your VIN into ePer and look up the part number.
http://eper.fiatklubpolska.pl/navi?FORCED=TRUE&GUI_LANG=3&LANGUAGE=3&COUNTRY=012&

It's unlikely to be the cable, it's always the sensor in my experience.

I always buy things in two when ordering from the UK, one for the car, one for the preventative maintenance kit.  It will go again stranding you (or a mates will) and it will cost more to ship than it's worth.

[colcol]

My JTS crank sensor had no cable with it, just unplug the cable and pull out the old crank sensor, buggered if i could see it from the top, so look at it from underneath, if i remember rightly, the twin sparks have a cable, but they are different to JTS's.
I would have swore on a stack of bibles that the sensor was at the front of the motor, but listen to Choderboy as he knows what he is talking about, i may have been standing on my head at the time and was disorientated.
If you have a look and join one of the UK Forums, they have photo's of it, as thats how i didn't find out where it was, when the sump was off the car i found it, having the car on a hoist may help, Colin.

[bloomers1176]

Thanks chaps. I am hoping to use a mates mates pit soon. However the light remains off?? )


Gonna run the ole girl to Mooloolaba this weekend. Just as soon as I have joined RACQ.

[Mick A]

If you remove the battery and tray on the 156 you may be able to reach down to it from the top.
I have changed plenty on 147's this way, as there is a bit more room to reach down due to the smaller intake tube.
It is 100% where I mentioned previously, under the starter motor right where the bell housing meets the block.

Cheers

Mick

[bloomers1176]

Sorry for late reply guys found it and replaced it, many thanks.  Diamond geezers the lot of ya