Temp gauge remains at 60c

[Brum1986]

Hi, I don't really post on these things much but I really need some help regarding my ford focus.

 

CAR DETAILS

 

Ford Focus

Zetec S

2009 (59)

1.8 TDCi

143500 current milage

 

ISSUE/CONCERN

 

So the temp gauge on my instrument cluster for the majority will never move from the 60c mark, this is regardless of whether a short trip locally or a couple of hours down a motorway. I say majority because on the very odd occasion it can creep up for a few seconds (75c - 80c) and then it will immediately drop back down to 60c.

 

I have an android head unit which has an OBD2 app pre installed which I can connect wirelessly via bluetooth to my OBD2 box.  This shows that the temperature is often somewhere between 9c to 15c and can sometimes drop to negative 4c.  On the odd occasion when the temp needle does rise to about 75c on the instrument cluster, the OBD temp shows at about 47c to 50c.

 

Tonight, I was travelling down the M42 towards Birmingham.  Up until the motorway (A Roads), the cluster temp needle remained at 60c with the OBD temp jumping around between negative 4c to 15c.  It's also did this down the M42 all the way to Birmingham, but it briefly rose to 58c and again, this showed at about  75c  on the cluster before quickly returning back to 60c.

 

There appears to be no pattern to when or how it happens, it just seems very random.  I have absolutely no issue with the heating.  If I turn the heating to hot, then it gets nice and toasty inside.  If I turn it to cold, it gets cold.

 

The fact that I'm getting heating is confusing me.  I initially though that it could be a thermostat stuck in the open position, but surely, I wouldn't get hot air, would I?  Would it more than likely be the temperature sensor, especially with fluctuations in temperatures, even when across a short range like negative 4c to 15c.

 

I've entered the the secret menu and conducted a guage sweep, and all gauges were working.  I cycled through the menu and the engine temp in the test menu corresponds with whatever is showing on the OBD2 app, which makes sense.

 

I've also noticed recently some very slight hesitation, usually in 2nd and 3rd gears, and it doesn't feel as if the power is quite there sometimes.

 

I brought the car because it is actually solid and in great condition which has been confirmed by several mechanics, and it had a full Ford service history up until a couple of years ago at the same dealer every time.

 

WORK SINCE OWNERSHIP

 

I brought the car April 2023 @ 133,000

 

Cambelt changed (wet + dry) @ 133,000

oil + filter change ( part of the above) @ 133,000

Brake pads @ 138,000

Spark Plugs and oil + filter change 143,000

 

Any assistance would be greatly appreciated.

 

[StephenFord]

My temperature gauge remains at this level all the time (apart from when when the heater matrix took a hissy fit!)

60c is very cool, and would be indicative of a faulty sender unit in my opinion, but someone sensible will be along soon...

[rd457]

5 hours ago, Brum1986 said:

I initially though that it could be a thermostat stuck in the open position, but surely, I wouldn't get hot air, would I?

Well yes you might actually, but I don't think it's the thermostat.

A stuck open thermostat is just going to result in the engine taking longer to get up to ideal operating temperature (~90°C). I'm not sure quite how long exactly it may take for it to reach this temp with a stuck open thermostat, and of course it would partly depend upon how aggressively you're driving, but a couple of hours of motorway driving should be far more than necessary, so that can't explain it.

You'll be getting hot air from the engine via the heater matrix, once the engine has warmed up, but you may also have an auxiliary heating element in the dash that supplements the heat you're getting from the engine when it's not enough to meet what you've demanded via the controls.

5 hours ago, Brum1986 said:

the OBD temp jumping around between negative 4c to 15c.  It's also did this down the M42 all the way to Birmingham, but it briefly rose to 58c

A reading of -4 to +15 is waaaaaay out of whack with what you should expect from a warmed up running engine (~90°C). It also shouldn't be jumping about and occasionally spiking much higher as you describe. Assuming that we can trust the source of this OBD data (and you did say that the info given via the IC screen in test mode matches that obtained via the fancy app based system, so we probably can), I think we can say for certain that the sensor is faulty (or something is up with its plug/wiring).

5 hours ago, Brum1986 said:

I've entered the the secret menu and conducted a guage sweep, and all gauges were working.

👍

5 hours ago, Brum1986 said:

On the odd occasion when the temp needle does rise to about 75c on the instrument cluster, the OBD temp shows at about 47c to 50c.

It's odd that the needle is not matching the digital data to such a significant degree, but I'd say this is an entirely separate issue, one simply of misaligned needle fitment. The needles are just pushed onto the ends of motor spindles. There's a common problem afflicting instrument clusters like yours of cracked solder joints on the wiring connector. The repair work for this cracked solder joint issue (speaking from experience) involves removing and refitting the needles. There's a knack to refitting them correctly such that they point (somewhat) accurately. One possible explanation for the significant mismatch in yours could be that the cluster has been sent off to have the solder joints repaired and whoever did it hasn't done a good enough job of refitting this needle.

Or, since the data is completely unreliable, jumping about and randomly spiking, it could just be a matter of timing; how frequently the IC is getting temp data updates from the ECU, how frequently it's adjusting the needle in response, and how frequently it's updating the data shown on the display. Perhaps it really is spiking up to ~75°C briefly, but at the point the screen was updated it had only spiked as far as ~50°C and it had fallen again before the value shown on the screen was next updated... 🤷‍♂️

I'd get the sensor replaced, see what effect this has on the temp readings, and then consider whether or not its worth bothering to try to adjusting the needle.

[StephenFord]

6 hours ago, rd457 said:

I'd get the sensor replaced, see what effect this has on the temp readings, and then consider whether or not its worth bothering to try to adjusting the needle.

Great idea... 😁

[Brum1986]

Hey,

Thank you for all the replies, especially rd457 as that was very detailed and  I genuinely appreciate it.  Could anyone advise on the location for the coolant sensor on the 1.8 TDCi?

[rd457]

Not certain, perhaps @TomsFocus or @unofix would know.

[unofix]

Tom, is your man for this engine but while he's not here I'll try and help.

[TomsFocus]

These use a cylinder head temp sensor, which partly explains your unusual readings.  It's measuring the head temp, not the coolant temp.  A calculation is then used to work out the coolant temp for the gauge.  A generic OBD temp reader may not be able to show the temp correctly as it's not a linear voltage output on this type of sensor, as it would be with a coolant temp sensor.

[Brum1986]

Hey guys,

 

Thanks for all the help and assistance, it really is appreciated.

 

I was able to find the temp sensor eventually, a little nub with a wire attached located in the engine kinda next to the fuel filter.  I have ordered a special socket which should arrive this evening and a new temperature sensor.

 

Just a bit of an update though.  As stated in my initial post, the engine was feeling a little sluggish and looking around in various forums / sites, I notice the EGR valve and these blanking plates appear to be a bit of a topic; as a result I ordered one which I installed this afternoon as I'm off work for a few days.

 

I haven't installed this as a permanent solution, but more to see if it would improve the sluggish performance, which is certainly did!  I'm guessing as a result of the improved performance, there could be an issue with my EGR?  Anyway...

 

Since installing the blanking plate it appears the temperature cluster and OBD reading have come alive.  This is either just a big coincidence, or there is some relationship, I have no idea.

 

I took the car for a decent test drive out of the city suburbs and onto a mixture of country roads and duel carriageways.  The temp rose and stayed pretty consistent and fluctuating only a few degrees.  The needle on the cluster rose to just shy of 90c and the temp on the OBD read between 58c to 61c.   When I turned the engine off, I turned the ignition to activate the instrument cluster, and the temperature very slowly started to fall like what you would expect as an engine cools.

 

I have no idea what to do now.  I guess it's still probably best to change the temp sensor, but I'm a little confused as to why it seems to now show a more consistent temp reading on a lengthy journey after installing this plate.  I can't say I've ever been aware of this.  I have seen fluctuating temps in the past, but they've been breif and erratic with it mainly sitting at zero. 

 

I'm going for another test drive this evening to see if it happens again.  I'm going to wait for the traffic to die down first as it isn't great around here during the peak.

[Brum1986]

Yeah, it's gone back to it's original behaviour 🙄🤦🏻‍♂️

[tazzman600]

Oh yes. EGR blanking is a contentious subject. Me? I'm All For blanking those pesky filthy things. And yes the blanks make a diesel run so much better. Well it did in my diesel days.

I recommend you start using Millers Oils Diesel Power Eco Max. I used that in the diesels I had and they ran sweeeeeet. I've used the petrol version in all my petrol cars too. It supercharges the fuel and cleans the fuel system too. A win win scenario 🙂