Technical temperature gauge

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Technical temperature gauge

patch201

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Could anyone inform if,when warmed up,should the temp gauge indicator always sit at the middle or go down to the quarter position when running as I feel that my 1.9 MJ Doblo is not warming up correctly.Cheers
 
Hi.

My 1.9 MJ temp guage sits right in the middle once it has warmed up. I think that you may have a thermostat problem which will cause you to use more fuel than you need, and will increase engine wear also.

Steve
 
mine always stays in the middle on my doblo but when i had my brava it was serviced thay put the wrong oil in it so when i was driving around normely it would stay at the middle but when on the motorway at 70ish it would drop to quarter
 
Hi Patch

The symptom that you describe is entirely due to a failing thermostat and is nothing to do with "wrong oil". You may have linked the two events incorrectly, as perhaps they occurred around the same time.

The reason that the gauge reading falls on the motorway is that you are normally using only part throttle load (less fuel burned) and so producing less heat in the engine. So there is less heat to dissipate in the radiator and this coupled with the failing thermostat and more cooling air flow through the radiator from the higher speed, leads to the engine running too cool.

Note that the thermostat may not have totally failed but it will be opening at too low a temperature - this is the normal failure mode.

Paul - the conclusion is that you need to replace the thermostat and the problem will be solved.

Steve
 
My Punto 75Elx has issue with never going above 1/4, but takes a white to reach this, 20/30 mins of driving. Believe this is most likely thermostat issue? if so will this issue cause the car to randomly cut out when stopping at lights or changing down gears? as I have been told the engine needs to be at 1/2 in order to run properly. (Im new to forums and i've seen other posts about this issue but they always seem to trail off into subject irrelevant to what the issue is). Your help will be much appreciated.

Thanks.
 
Hello everyone
We have a 07 Doblo (1.9 multimeter) we have only had it 5 days and suddenly the temperature gauge shot up to high (red) for 2 seconds and the engine cut out. The engine symbol on the dash board came on. The car started straight away but the problem keeps reoccurring. I will be taking the car back but I would like to know if it is the temperature sensor in the engine.
Can anyone help?
Nedlog
 
Hello everyone
We have a 07 Doblo (1.9 multimeter) we have only had it 5 days and suddenly the temperature gauge shot up to high (red) for 2 seconds and the engine cut out. The engine symbol on the dash board came on. The car started straight away but the problem keeps reoccurring. I will be taking the car back but I would like to know if it is the temperature sensor in the engine.
Can anyone help?
Nedlog


Solved. It was a faulty relay
 
Not solved. I drove the 50 miles from Featherstone back home, ok.
The day after the temperature gauge shot up to high ageing for 3 seconds and the engine cut out.
This happened 20 times and I had to call Greenflag again.
It even shots up when the engine has stopped with the ignition on.

Any suggestions?
 
Surely if it was the voltage regulator, other systems would be affected?!

It may be the ECU is getting a stray signal form something, hence the shut off.

I would be looking at a bad earth or a chafed wire in the loom from the sensor to the dash.
 
Still no joy. The car has gone back to the garage so that the auto sparks can look at it. Luckily when the chap I bought it off came to pick it up on his low loader it did it three times.

Does the fan cut in at a certain temperature and if there is a fuse blown or some thing wrong with the wiring to the fan would the engine management cut out?
 
The fan cuts in at a pre-determined temperature (like how the thermostat will open at a given 89c of instance) which is usually around the same as a stat.

It is entirely possible there is a short between the switch and the fan, but in my experience, the fan never cuts in while traveling at speeds above 10mph as the through flow of air keeps the coolant at ambient.

If the engine overheats seriously enough for it to cut out, you would feel the heat in the interior cabin go up beyond the normal full heat. Also, there would normally be bubbling sounds and/or steam escaping from the radiator cap or worse, coolant boiling out the overflow!

I would imagine a short circuit from a chafed wire or a blown switch.

I remember several years ago rescuing two babies from a Renault. I was heading towards it and heard peeping & shouting from irate drivers. But I could see what they couldn't, the front lights were glowing and smoke was pouring out from under the bonnet. The car wasn't moving as the engine had died. The mother was frantic (and the selfish peeping clowns weren't helping :mad: ) so I told her to unhook the belts & get the babies into my car while I dealt with the fire.

Turned out the wire from the fan to the loom went direct to the battery + and some twit, upon replacing the battery with a more powerful new one, had placed the battery on top of the wire. Subsequent chafing made it wear through and start melting the plastic, which caught fire. Worse still, the fuel line ran alongside the wire :eek:

Ha ha ha, she called the local radio to say thank you to me as I was a hero :worship:

I wan't, I was just in the right place at the right time. But I was pleased at the thanks from the fire chief :eek:
 
The cab doesn't get any warmer than normal.
When the chap came to pick it up I sat in the car with the engine going to get the temp up to mid way. When it got there and after running for a few minutes the engine stopped and then the needle shot up to over heating for 3 seconds then came down again. (In that order)
It also did it WITH OUT THE ENGINE RUNNING.
It did it 3 time whilst the chap was loading it onto the low loader.

He said that it hasn't done it since!
Auto sparks has been looking but he can't find anything yet.

We bought the car 18 days ago. It's been on a low loader three times and we have only been able to use it for 4 days apart from picking it up.
 
" then the needle shot up to over heating for 3 seconds then came down again. "

That's my point!

IF the car WAS overheating, you would first get the symptoms I described, but the needle would stay in the red for at least 20 minutes! :eek:

I am still convinced it's a short, a chafed wire or it may be the ECU.

However, I rather think the ECU is merely reacting to a signal from the temp sensor wire.

The temp sensor is usually a grounded wire in that the signal from the sensor is received through an earth to the sensor, then variable resistance through the sensor as it reacts to heat.

So, it allows a grounded signal to gain voltage and this signal is sent to the temp guage. The guage in itself is fed 12v constant via the dash. The needle reacts to the negative signal.

So, I would be checking earth connections at the engine & engine bay. Then the wire from the sensor to the loom, then through the loom to the dash.
 
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