C5, how hot should it be??

[Jetjockey]

Morning!

A quick query regarding the engine temp dashboard readout please. On the bar graph I’m getting generally 5 bars. It occasionally drops to 4, and occasionally rises to 6 bars. This equates to maybe just under half scale. Is this correct?
I ask because I’ve seen pictures showing 3/4 scale on the bar graph and the vehicle is somewhat heavy on diesel.
It’s a 2008 C5 Exclusive Tourer 2ltr diesel 130Bhp.

I used to have an E320 Mercedes that suffered with a similar common problem and it cost £35 for a complete new housing. Citroen want £126!!!!
I need to be sure it’s faulty before changing it!

Many Thanks.

[Jetjockey]

[white exec]

Dash gauges can be notoriously vague or inaccurate.
There are a good many non-contact digital IR thermometers available now, ludicrously cheap.
I bought one of these
https://www.amazon.co.uk/AstroAI-Infrar ... fkmr0&th=1
a while ago, and found it to be very accurate.

Best when pointed at dark objects (which radiate heat well), the instructions say, which is no problem when checking under-bonnet objects such as hoses, thermostats, or electrical components, and even exhausts!
There are cheaper models, with smaller temperature ranges.

[Jetjockey]

Hello White Exec.

Thanks for that, and I see what your saying, I actually already have a Maplin version of that very instrument.
I think the average temp on most cars is about 90°C?

However, I have no reason to distrust the gauge, I’ve never had problems with a coolant temp gauge before in any of my cars.

I’m thinking there must be many people out there driving these C5’s and know where the gauge sits on a daily basis whilst driving around.

Anyone?

[Gibbo2286]

Mine sits at the bottom, only rises to the centre mark when crawling along in heavy traffic, I ignore it, it never actually overheats or consumes any water, never needs a top up.

I'd guess the sensor is faulty, as said in an earlier post that seems to be a common problem on these, had to replace one on my previous C5.

Ps. You say it's somewhat heavy on fuel, what mpg are you getting?

[Jetjockey]

Hello Gibbo.

According to the on board computer I’m getting about 34 on combined driving, in reality it seems more like 30mpg.
It certainly seems heavy on gas for a diesel (it’s an auto).

Where is the sensor situated? Is it an easy change?

Thanks.

[Gibbo2286]

Probably not too far out for that, it's a heavy car, I think mine is not much different, certainly under 40mpg over the time I've owned it but my motoring is mostly pottering around locally with only a decent long run about once a month

[Peter.N.]

Mine both run at about 4 or 5 bars depending on ambient temperature, or at least they do now I have replaced the thermostat in one of them. If the thermostat is faulty it will show up best on a long descent in very cold weather when if faulty it could drop to 1 or 0 even, that's what mine was doing but since replacing the stat it reads the same as the other one.

Peter

[Jetjockey]

Thanks both, I take your points.

I’ll keep a close eye on it over the next week or so.

Thanks.

[GiveMeABreak]

Don't panic about it - there are other warnings that will appear if there is a problem, including the stop lamp.

The first 11 segments are normal and are within the normal operating range.

"P" Valid temperature zone: The temperature is correct
"Q" Excessive temperature zone: The maximum temperature warning light and the central STOP warning light come on, accompanied by an audible signal and a message on the instrument panel display