Thermostats - troubleshooting

[Jetjockey]

Hello Peter.

My car is a C5? Or do you mean the saloon?

[Peter.N.]

I didn't see the metal bracket that supports the wiring in your pics. Is yours an earlier one? Mine are 2008 X7s.

Peter

[white exec]

Sounds like substantial improvement.
A properly working thermostat prevents large temperature fluctuations (and heater output), especially in cold weather. Rad fans are supposed to do some work!

[Jetjockey]

Hello again.

Yes, mine had the metal bracket but unfortunately I didn’t think to start taking pics until I’d dismantled it all. Dohh!

[Peter.N.]

Oh right, you did even better then!!

Peter

[KennyW]

Be careful when removing the valve cap at the matrix on my xantia it was so tight it broke off resulting in a repair using a rubber tyre valve. Valve removed.

This work until the car was written off.

Kenny

[jauv]

I've got a 2.0i 16 valve Xantia and it gets a bit toasty in a standstill - in fact the cabin air gets noticeably hotter. Fan kicks in at 105-110 Celsius and gets the thermals somewhat back in check. Will a thermostat change likely fix this behaviour? Kinda on me on not noticing this initially, but I live in a colder climate.

[white exec]

Are fans only kicking in at 105-110 ? Would have thought they should also be operating at a lower temperature - 'slow' speed - as well.
At slow speed, fans operate in series, and if one fan is dud (open circuit) this will prevent both from operating in slow speed mode. Nothing will happen until the temp climbs still further. If one fan is a dead short, slow speed will show up as fast. When temp does climb further, the fans are switched to parallel, when the good one will run, but on its own.
Check fans, their fuses, and the trio of relays that operate them.

With IGN on, if you unplug the brown temp sensor, both fans should momentarily run at slow speed, and then switch to fast. To stop this, reconnect, and switch IGN off then on.

Note: Both fans should always run at the same speed as each other. If they run differently, there is a fault.

[Rhothgar]

I am surprised you are getting to 105-110.

Maybe in rural mountainous regions of Austria in Summer or maybe temperate conditions I would expect this but not in say -20 degC . Then again I am not sure I would.

To my mind, it sounds as though you may have a head gasket issue. Is the level correct in your header tank?

[white exec]

If slow fan speed isn't operating (and this does the majority of normal engine cooling), the temp will climb higher than usual, until fast speed finally kicks in. This could occur in traffic jams as well.

[jauv]

Thanks white exec, that makes perfect sense. I'll update here if that's indeed the issue, but it's probably going to be a while. Life's bit of a mess right now.

And thanks Rhothgar as well, I don't think it's a head gasket problem, as for example fluids don't look mixed and the engine doesn't show other similar issues (though I haven't done a proper compression test) but I'll keep that in mind.

[antb1981]

Hi there got a pug 308 1.6vti 08 plate and my thermostat is leaking. The only trouble is I've only got 1 x 2 pin plug on it, does anybody know where the wiring harness modification plugs in. My car has the original thermostat on it as it's only done 24k miles. All the new thermostats have 2x 2 pin plugs on it, and you can get a 4pin to 2x 2pin adapter wire, which doesn't work with my car.
Thanks Anthony

[white exec]

Hi Anthony, and welcome.
Can you post the car's VIN number, so we can identify the exact installation?
Thanks.

[antb1981]

Hi chris
Here is an attachment of my vin number..
VF3**************[VIN obfuscated, can be read by forum staff]
Thanks for your help
Anthony

[antb1981]

Hi there, did anybody find any info on my wiring. As need to get this done while I'm bored at home lol. Thanks again anthony.