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Driving temp & overheating

1K views 16 replies 7 participants last post by  johnlear 
#1 ·
So my 156 1.8 TS CF3 is running at around 85°c under normal conditions (main roads) - around 90°c on motorway, and it heats up as quick as I expect it.
However, sitting in traffic, even at days with only 18-20°c ambient temp, it will quickly heat up to +95°c.
The radiator itself is new (replaced by previous owner). Considering that heat-up and running temp is ok, I have a hard time believing that it's the thermostat causing this (unless of course it doesn't open fully).
The fan runs - although, I haven't checked if it actually goes on both speeds.

Where do I start? Say my fan does run on both speeds, then what?
I wouldn't dare a road trip to Italy, risking a traffic jam in 40°c...
 
#2 ·
To me it sounds like your fan only run at high speed.
If the temperature rises and the fan kicks in, do the temperature continue to rise?

If the fan only run on high speed it is probably the resistor unit or the low speed relay that has broken
Do you have the wiring diagram?
 
#3 ·
The temp doesn't go down with the fan running.. So I'm more inclined to think it goes opposite of what you're saying - that it maybe only runs on low speed.
I will check fan speeds later today.

Forgot to mention that there's no coolant useage and level is fine as well.

I have access to AutoData, so I can pull out a diagram yes :)
 
#4 ·
The temp doesn't go down with the fan running.. So I'm more inclined to think it goes opposite of what you're saying - that it maybe only runs on low speed.
I will check fan speeds later today.
......
I would also, if possible, compare the temperature as read via OBD with that displayed on the gauge (the OBD temp is the temp as read by the ECU).... The gauges on 156 have been known to be off.
Fans etc are controlled by the ECU, which uses a separate temp sensor. Gauge has it's own sensor.
 
#5 ·
I would also, if possible, compare the temperature as read via OBD with that displayed on the gauge (the OBD temp is the temp as read by the ECU).... The gauges on 156 have been known to be off.
Fans etc are controlled by the ECU, which uses a separate temp sensor. Gauge has it's own sensor.
I'm aware the gauge is off - the temps I provided in the posts are actual temps, not read from the gauge, but through OBD ;)
 
#8 ·
That high, really? My fan is mostly on, when I pull into my drive-way on the way home from work.. As I mentioned it's usually around 85°c under normal conditions, so why is it on that "low"? Because of AC?

Well I've seen it up to 98°c, before I've chosen to put the interior heating on full blast to keep it down..

I was unable to activate the fan relays via AlfaOBD, but I will try switching the relays around, just to verify that both relays are OK.
 
#9 ·
If you turn on the AC, the fan will be on low speed if the condenser needs to be cooled.
If you can't activate the fan relays with AlfaOBD then try a free version of MultiECUscan to see if it will activate the fan relays

NB. you can PM me via AlfaOwner or via AlfaClub Denmark if you need live help.
 
#15 ·
I haven't.. And unfortunately I'll be busy most weekend, so won't be able to check until sometime next week.
 
#16 ·
As already said, that's quite normal temperature readings as long as the fan kicks in at both speeds. If it was a K series rover, then I'd be concerned above 130c but not on a twinny.
Try bleeding the radiator. Get it up to full temperature remove the expansion cap and once the fan kicks in and open the plastic screw on the top left of the radiator O/S allow it to flow freely then close and top up coolant. Job done. Chances are you'll have a little trapped air which can raise the temp in a pressurised system.
 
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