Ranger Mods

On a caravanning loop around WA and having an error come up more regularly 'Coolant Over Temperature Alarm ' and it almost immediately disappears. The gauge in the dash moves around quite a bit, never above half temp but bounces along as we drive. Often when the alarm occurs, the temp gauge is showing the blue line off the bottom, i.e. very low temp, and then it comes back up and the alarm goes away. The temp is not high generally.
When I had the OBDlink and Torque connected the temp would bounce around between say 73-83C.
Had the car into Titan Ford in Perth who gave it a once over and could not fault it. The drove it and said 'could not simulate' ... as expected given it only occurs intermittently. their suggestion was to go into another dealer with the caravan on the back! Which I think is bull....

So while the alarm has not occurred when driving without the caravan on the back, we have only done fairly shot trips, say 1 hour, the temp gauge bouncing still occurs without the van. I cannot see any reason the van would be impacting this-?

I have taken the OCBlink off incase this was causing a problem, this has only started happening on this trip and I only installed the ODBlink just before we headed off. I had a coupe of other errors with sensors happening as per an earlier post but these seem to be sorted now.
Is there any way the Torque app and OBDlink could have caused a problem like this with my coolant sensor?

Any other suggestions other than the sensor or wiring? Can anyone point me to the coolant sensor location?

Any ideas welcome before I get home and go see another dealer.

I have an OBDLink MX Bluetooth permanently plugged into the second port and haven't had any issues as you describe.
My engine temp sits around 86 when towing the van, it may rise to 88 when climbing but soon drops back when the load is off.
If yours is running at 73 that seems a bit low to me and the fluctuations may be indicating a fauily sensor.
Wait for a reply from Stewart.

May be a sticking thermostat ?

Coolant temp sensor is below the throttle body. It the best way I can describe it without post images.

73 seems low, personally I would be monitoring it with another tool to confirm as you are just relying on OBDlink and software having no issues.

Thanks for the thoughts. Interestingly the alarm/display message comes up on the dash as Coolant Over temperature Alarm but at the instant it comes up , the temp gauge blue line drops down to the bottom or off the scale cold. It is weird as I can drive for an hour or more sometimes and no alarm but the blue line is still fluctuating around below half way. Then it starts to occur and continues as we drive.
I am suspecting a sensor, I can't imagine a thermostat creating such varying temperatures so quickly.
Will have a look for the sensor just to check the wire is a good connection.

just an update- put the Torque app back on with OBDlink and scanned - returned an intermittent coolant temp error so I have all I need. Will see what Ford think the cause is soon.

seany-boy wrote: ↑Sat Jul 20, 2019 2:23 pm just an update- put the Torque app back on with OBDlink and scanned - returned an intermittent coolant temp error so I have all I need. Will see what Ford think the cause is soon.

Good work on finding the actual issue.

RossPat wrote: ↑Mon Jul 08, 2019 9:01 am I have an OBDLink MX Bluetooth permanently plugged into the second port and haven't had any issues as you describe.
My engine temp sits around 86 when towing the van, it may rise to 88 when climbing but soon drops back when the load is off.
If yours is running at 73 that seems a bit low to me and the fluctuations may be indicating a fauily sensor.
Wait for a reply from Stewart.

You have a second port on your Ranger? Is that a 2018 thing? Where abouts are the ports situated?
Thanks.

Not sure about the PX3, but yes, the PX2 certainly does. Have a look here... viewtopic.php?f=3&t=1541&p=7490&hilit=s ... port#p4690

interesting - maybe for some- update. Took the vehicle to Ford dealer in Adelaide, they could see and read the fault but said it did not provide them with enough info to actually confirm what part was likely faulty. They are not able to work on a warranty issue unless they can replicate the fault as Ford will only pay them to look into an issue if they can see it happen and further diagnose,put probes etc. The fault has only happened once without the caravan on so seems to be load or duration related- maybe after an hour or so it seemed to get worse. Would not change the sensor unless I paid for it!
The error occurs when the temp indicator actually drops off the gauge- so no reading - even though the errors reads over temperature alarm.
So I still have the issue, drove back to Melbourne, happened frequently on the trip back but once here has only occurred as not towing the van!
Have to wait for it to become more consistent really.

Ok, I did some testing for you.

You have a dead short. Sensor is stuff or you have a wire short to earth, check under the front cover near the front of the engine to make sure the look has not rubbed through to the engine.

So what happens on a dead short. Temp goes to 150 degrees Celsius and the coolant indicator goes to the bottom, it would be a diagnostic feature I would say and the right person in engineering would have the answer.

FYI, full range of reading of this sensor with diagnostics is -40 to 150.

See below image.


I have also learned that the true value that an over temp will come on is 115 degrees Celsius. The below image will show the alert and where the gauge would be when it triggers.

Testing shows that if it was a true over temp you would see the gauge rise from normal temp to full in a smooth pattern. If it is instantly going from normal to the fault then it has nothing to do with temps.

Thanks Stewart,
Apologies for lack of response , for some reason I don't receive notifications of posts even though subscribed (same as the Newranger forum) The cover you mention is that an engine cover? I will take a look tomorrow. You analysis is spot on, the intermittent nature suggests to me a wiring fault, I have not had a chance to go on a longer drive without the van on.

Sean

seany-boy wrote: ↑Sun Aug 25, 2019 10:45 pm Thanks Stewart,
Apologies for lack of response , for some reason I don't receive notifications of posts even though subscribed (same as the Newranger forum) The cover you mention is that an engine cover? I will take a look tomorrow. You analysis is spot on, the intermittent nature suggests to me a wiring fault, I have not had a chance to go on a longer drive without the van on.

Sean

Is your email address correct? If not check you spam/junk box as they do work 100%.

Pull off plastic engine cover then look at loom across the front top of engine. It is the main engine loom.

Gotcha, i will take a look. I re-subscribed last night and got the two messages you left so thanks. I will try the newranger forum again and see if that works. Dont think it is operator error but then never can tell!

Sent from my SM-G930F using Tapatalk

seany-boy wrote: ↑Mon Aug 26, 2019 5:21 pm Gotcha, i will take a look. I re-subscribed last night and got the two messages you left so thanks. I will try the newranger forum again and see if that works. Dont think it is operator error but then never can tell!

Sent from my SM-G930F using Tapatalk

No, emails there just do not work full stop.

another quick update incase it is of interest. The loom looks fine, at least externally and now the alarm is happening without the van on and almost every time I go for a drive which is great.
I talked to Knox Ford and the ute is under warranty untilApril so I will keep driving and hope it gets worse before then. Definitely sounds like a sensor dying.

Hopefully it coming n more frequently will help to resolve the matter.

Hey Stewart,
I used my Torque app and tracked my Engine Coolant temperature in a graph to see it varying. If you have time could you do similar with an ODB link app? Mine moves around a fair bit and hopefully yours stays rock steady once warm.

Cheers

Sean

ok, finally got it back into Ford service and was able to show them the display varying very regularly and Stuart you hit it bang on- it was a broken wire in the loom for the coolant sensor. They said the first time they had seen it so I told them you had diagnosed that as the issue!
Thanks heaps.

Good outcome, at least you can stress less now.

seany-boy wrote: ↑Wed Mar 03, 2021 8:41 am..it was a broken wire in the loom for the coolant sensor.

Do you know where the break was?

in the main loom very close to the coolant sensor apparently. I am not sure where the sensor actually is but Stuart knows the location. I am thinking it was an intermittent contact/open circuit break.

seany-boy wrote: ↑Wed Mar 03, 2021 8:41 am They said the first time they had seen it

Haha god i love that line.