Hi Guys,

The latest update on my JTD - any suggestions are more than welcome:

Firstly, my car is a 2001 X Marea SX Weekend 105 JTD with 104,500 miles on the clock b ut has been well serviced.

Having read all the threads with interest about the various cooling system issues these cars are prone to, i've got a slightly strange quirk on mine (I know its Italian and that's why we love 'em!).

The car was running a little sluggish, temp gauge was irratic to say the least (seemed to change rapidly once the engine heated up and went up and down for no apparant reason!), sometimes going right up into the red but not seeming to be overheating.
The other noticable fault was the "auto" setting on the interior heater seemed to be more like a "random" setting, with the temperature wildly changing from too hot to cold with not change to the controls.
So, to be on the safe side, it went to a local independant garage owned by a family friend (so i know he's always honest with me).
A compression test was done, and thankfully, no signs of any headgasket failure. The thermostat was replace (brand new item from local Fiat dealers) and the temperature sender was also replaced with new. An oil and filter change was also done at the same time (seemed sensible to do whilst it was there anyway).

On my first proper run (about 40 miles of motorway to work) today, the temperature gauge went off the top of the scale by the time i arrived at work (past the red and as far as the needle can travel). When i stopped and checked the car, the engine was not seeming to run hot, there was no sign of steam, the water looks fine (no leaks, no drop in level). The interior temperature seems to be much more stable now but the temp gauge is concerning.

It is also worth noting that the gauge "flickers" up and down randomly and on occasion will go from red to central (normal) mark for a couple of seconds then back again - ie. not a steady increase like it's overheating.

My thoughts are that is must either be the gauge itself not processing the signal form the thermostat / sender correctly or that it's some sort of issue with the water pump not circulating the water. I have only had the car a couple of months and there is nothing in the history to show the cambelt / waterpump being done but the belt certainly looks to be recent.

Is is possible for the water pump to fail in a "freewheeling" state rather than to seize and snap the belt? If so, would this cause the faults above?

I'm stuck for cash and don't want to have to spend out on a water pump / cambelt change if i can possible avoid it or if there is something cheaper and easier to try first (hence the thermostat / sender change).

Any ideas are greatly appreciated.

Thanks in advance.

Normally if you overheat, it will stop blowing warm air out the heater, and you'd notice a drop in coolant level. If it's still blowing warm air out then I think the problem isn't overheating.

With you saying the needle flickers between normal and off the scale I reckon the wire from sender is shorting to earth somewhere, causing gauge to read at top of the scale. It's worth giving the wires from sender a wiggle if needle is off scale again see what happens.

dont worry, its not overheating, its a wiring or gauge problem, the senders do go but you have eliminated that when you replaced it.

check the gauge connections by pulling the instrument cluster out slightly and wiggle the connectors at the top, and then tap the pcb (circuit board) with a screwdriver handle etc. around the area of the temp gauge. If it acts up while doing any of this, reseat the connectors by disconnecting and reconnecting them several times to wipe the contacts. you could also try separating the PCB from the cluster body to reseat the connections between the gauges and the PCB, but this involves dismantling it.

IMPORTANT : Before disconnecting the instrument cluster connectors, either disconnect the battery earth lead, or make sure the ignition is off. failure to do this may make the airbag light stay on (if it wasnt on already )

Owen.

A new component is not always a good component. The sender is in the order of 500 ohms to 1.5K from memory. You could try a potentiometer of about that value and twiddle it and see how the gauge performs. If it still jumps about the it's a connection for sure. On my car the gauge is driven from the ECU, don't know about yours.

Thanks for the advice guys.

The latest update is that i am now about 99.9% certain that the gauge (or the cable connecting to it) is the issue. After getting frustated at the needle going so far into the red yet again yesterday i gave the dash a "friendly" thump! The needle dropped back to dead centre and stayed there for more or less all the journey home (it had the odd little flick off the top of the scale but kept returning to normal).

The conclusion is that it's simply italian electric syndrome (again!!!).

I can't help wondering if i were to spend the equivalent to the value of my house (lottery win pending - just gotta remember to get a ticket before Saturday!!!!) on a spanking new Ferrari then would the electrics bugger up just as quick?

Oh well, at least it's better than owning a Rover - at least Fiats tend to keep going (even if the dash tells the odd 'little white lie').

pleinichen said:

Oh well, at least it's better than owning a Rover - at least Fiats tend to keep going (even if the dash tells the odd 'little white lie').

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I've had more grief from this Marea than from ANY Rover I've had and I've had a few

mach1rob said:

Normally if you overheat, it will stop blowing warm air out the heater, and you'd notice a drop in coolant level. If it's still blowing warm air out then I think the problem isn't overheating.

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Why is this? When you overheat, there is no heating? I don't understand...