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Temperature Gauge Problem?

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Hi

 

Wonder if anyone can offer any help... The dashboard temperature gauge on my Opel Manta GTE Exec Coupe is flying into the red only a few miles into every outing.

I have had the water pump checked, the radiator checked, the cylinder head gasket is good (no water in the oil) and two different thermostats fitted with no success. The most recent attempt to sort this problem was to fit a new Engine Temp Sensor.

Still no resolution.

The Engine temp sensor was a white unit and my mechanic has suggested that there could be other engine temp sensors with different ratings available... 

Any ideas? I am really nervous about taking the car out at the moment...

I am a new member (rejoined...) 

I bought my Manta in 2000, and had her restored by Andy Turner in 2012.

I live in Dumfries, Scotland and would be really interested to hear of any mechanical expertise in the area who could help me maintain her...

 

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^^What he said.

I would go to Maplin and get a digital thermometer and remote thermocouple to allay fears by verifying actual temp if need be,

There is a procedure in the Haynes manual for checking petrol gauge something about a 40 Ohm resistor IIRC. Point being voltage stabiliser affects both temp and tank equally so you can prove if it is off that way.

Or a couple of quid http://forums.mantaclub.org/topic/30867-temperature-gauge/

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half way is where your gauge should sit.

i had loads of problems with my manta thermostat my temp was not getting warm so i replaced my stat.  the haynes manual says there should be a 92deg thermostat in it, but my car came fitted with a 75 deg stat. standard.

so i bought a 92deg stat and the car temp went into the red, and the car started boiling over. so i then bought a 87 deg stat, and my temp was still near the red, but was not boiling over. 

so a managed to get a new 75 deg stat now my temp gets to half way in 3 mins driving and stays there, spot on, the haynes manual must be wrong for my 78 manta, as my car is now spot on with the 75 deg stat, which it was fitted with

 

i think modern high temp stats of 92 deg is not right for my car. 

its worth checking your stat, temp rating.

Edited by droop snoot hp firenza

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Hi. The gte would have been fitted with a 92deg stat so thats the correct one. Should bring the guage up to two thirds of the guage. The 40 ohm resistor test works a treat and can be used to test most if not all vauxhalls/ opels from the 70s 80s and most likely newer stuff as well. Just get a 40 ohmresistor from maplins or similar or any local friendly tv / radio repair shop.unplug the wire from the sender unit.connect to resistor .other end of resistor to a good earth and the guage should go about halfway to two thirds. It will more than likely go all the way into the red confirming that its the voltage regulator on the back of the dash thats faulty.easy enough to change if not a touch fiddly. Remove rh heater duct first for easier access.you can see the regulator if you get your head down by the pedals and look up.

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One note. . . You said the engine temp sensor was white. That doesnt sound like the temp sensor for the guage. More like the one for the injection ? Anyway the temp sender unit is a small brass single spade connector unit on the side of the thermostat housing.removeable with a 13mm spanner

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Well known problem with Opels of that generation.It has also influence on your gauge of the feul reservoir.

Had also once the problem. Changed the voltage regulator by an electronic one.

Drivers seat complete back, Take a flash-light, lay with your head under the dash. Push the ventilation tube aside

and you see a little metal box on the back of the instrumental-panel. Pull it carefully off and install the new one. 

 

P1010202.jpg

The temp sensor is the little one next to the big brown one.

 

Edited by H-400

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hi its worth taking a look at this previous thread on the manta temp gauge readings. it seams a few of us have had problems when changing our thermostats. and gauges going into the red, is the 92 deg stat right for the manta? or could it cause problems fitting a non factory fitted stat in

http://forums.mantaclub.org/topic/31336-temp-gauge-position/

Edited by droop snoot hp firenza

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The temp sensor as said are different colours for different applications.

White red and black collar near wire connection.

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It's almost certainly voltage regulator. Simple thing to remember is that if it gets into the red properly rather than pretending, it will start pushing water out of the rad cap.

As was suggested, get an infra red thermometer from maplin etc as it's always useful to have anyway and you can check how hot it actually is

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We have that in our workshop, if I need it I just have to ask for it.

It is something so usefull I bought one myself, it is not that expensive and if you know the temperature exactly there is no discussion!

Buy it.

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Good thing I checked search bar works as I was about to write about my Temp sensor problem and it seems my newly acquired Voltage Stabilizer will come in to use (arrived today).

I have changed my clocks to the older style (SR) and the temp gauge is off the scale, were as my old original clocks (GTE Exclusive) it hardly moved.

Is there any difference in them except for the facelift (Cover)? Not that bothered just thought I would ask, and it's on a C20XE engine.

I wasn't that bothered about the reading as the car was stationary and seemed to be running okay with fan cutting in as per normal.

Cheers for all this previous right up.

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There is no physical difference in the temp gauges.

The older SR clocks have a better voltmeter - same type of gauge as the oil pressure gauge.

They are freely interchangeable.  I run the older SR circuit board and voltmeter with the other 5 gauges from my exclusive.

Changing the dash should not alter the reading without a defect. 

  • Like 1

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53 minutes ago, mantadoc said:

There is no physical difference in the temp gauges.

The older SR clocks have a better voltmeter - same type of gauge as the oil pressure gauge.

They are freely interchangeable.  I run the older SR circuit board and voltmeter with the other 5 gauges from my exclusive.

Changing the dash should not alter the reading without a defect. 

Cheers I thought there was no or very little difference just one gauge reading low the other high and it is 30 years old.

I changed them (SR) over on to my exclusive circuit board.

Just glad to have it running again after more fuel pipe problems :unsure:

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1981-ish and older 6 clock board is different, later one is the same as the GTEs / Exclusives.  The older voltmeter only fits the older board

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20 hours ago, mantadoc said:

1981-ish and older 6 clock board is different, later one is the same as the GTEs / Exclusives.  The older voltmeter only fits the older board

Mine must be post 81 as all the clocks transferred across no problem. :thumbup and I reassembled the other as a spare just incase.

Thanks for the help and information.

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