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Omega Help Area => Omega General Help => Topic started by: devonian on 04 March 2007, 21:26:41

Title: Temerature gauge
Post by: devonian on 04 March 2007, 21:26:41
Hi, hope somebody can help here....

Driving car today had covrd about 50 miles, car running fine...all of a sudden temp gauge shoots up to 100c+ and then drops suddenly back down again (too quick for it to be fan cutting in?). Then starts to behave very erratically up and down the gauge first red hot then back to normal.

Stopped as soon as able and popped open the bonnet, but no signs of overheating, no steam, expansion tank full and not overhot to the touch?!

Also car running normally no loss of power or any warning lights or EML light.....very strange.

Is this a major problem or possibly just a faulty sensor or thermostat??

Dave
Title: Re: Temerature gauge
Post by: Chopsdad on 04 March 2007, 21:34:54
If the fan isn't cutting in and it returns to normal, I'd suggest faulty thermostat.

I had one supplied and fitted last year for about £30 - so not the end of the earth.  :y
Title: Re: Temerature gauge
Post by: sounds2k on 04 March 2007, 21:38:13
bear in mind that on the V6 engines, the thermostat sits in the valley between the two banks so there's a bit of disassembly required before you can get access to it, accordingly I'd expect it to cost a bit more than £30!

JamesCDX has just done MaxV6's ... the temperature sensor however runs off the coolant bridge, it's a single spade connector so it might be worth checking that's connected OK - but again it will require removal of the wipers and scuttle at least ...
Title: Re: Temerature gauge
Post by: TheBoy on 04 March 2007, 21:39:07
Or a faulty sender unit, or water dripping on sender...
Title: Re: Temerature gauge
Post by: sounds2k on 04 March 2007, 21:40:26
... it could also be a faulty temp display in the dash - which is not unheard of ...
Title: Re: Temerature gauge
Post by: Chopsdad on 04 March 2007, 21:42:15
Quote
bear in mind that on the V6 engines, the thermostat sits in the valley between the two banks so there's a bit of disassembly required before you can get access to it, accordingly I'd expect it to cost a bit more than £30!

JamesCDX has just done MaxV6's ... the temperature sensor however runs off the coolant bridge, it's a single spade connector so it might be worth checking that's connected OK - but again it will require removal of the wipers and scuttle at least ...

Sorry, missed the 2 extra cylinders - plenty of room to get at it in a 2.2  ;)
Title: Re: Temerature gauge
Post by: TheBoy on 04 March 2007, 22:06:51
Quote
... it could also be a faulty temp display in the dash - which is not unheard of ...
Tends to go the other way in my experience...
Title: Re: Temerature gauge
Post by: Andy B on 04 March 2007, 22:54:14
Quote
... it could also be a faulty temp display in the dash - which is not unheard of ...

You can prove the gauge by earthing the wire that goes to the temp sender, when you do so the gauge should go all the way to HOT.
Title: Re: Temerature gauge
Post by: devonian on 05 March 2007, 18:22:36
thanks guys, at least its not too serious, was bit worried for a while! Will have to have a play around...

Just for info whereabouts is the temp sensor located?
Title: Re: Temerature gauge
Post by: Andy B on 05 March 2007, 18:30:08
Quote
thanks guys, at least its not too serious, was bit worried for a while! Will have to have a play around...

Just for info whereabouts is the temp sensor located?
Right at the back of the engine - in the V
Title: Re: Temerature gauge
Post by: devonian on 05 March 2007, 18:32:19
cheers Andy  ;)
Title: Re: Temerature gauge
Post by: chris b on 05 March 2007, 19:01:31
 :-[ if i can rember m8 its a pig of a job. had a pipe split on me and thats in the same place. hope you havent got big hands yul never get them in ha ha. gud look. :y
Title: Re: Temerature gauge
Post by: TheBoy on 05 March 2007, 19:02:43
It is possible to do without any dismantling, but its far easier to take scuttle off...
Title: Re: Temerature gauge
Post by: Gaffers on 06 March 2007, 09:00:38
I wonder if I have a similar problem.  My ecu light has been on for a bit now and the code states temp sensor voltage low.  I also got a faint smell of coolant yesterday for about 2 minutes.  So I stopped popped the bonnet, coolant level had dropped about 1cm after about 400 miles, the smell seemed to come from the back. Does this point to the same kind of problem?

Gaffers
Title: Re: Temerature gauge
Post by: Marks DTM Calib on 06 March 2007, 09:05:25
If you aheva  fault light and it says coolant temp sensor....then change it as it will be costing you in petrol.....unless some numpty has fitted one of those stupid ebay resistors....

As for the gauge shooting up....it might simply be the wire catching on the engine and shorting it to 0V.....
Title: Re: Temerature gauge
Post by: Andy B on 06 March 2007, 19:02:48
Quote
I wonder if I have a similar problem.  My ecu light has been on for a bit now and the code states temp sensor voltage low.  I also got a faint smell of coolant yesterday for about 2 minutes.  So I stopped popped the bonnet, coolant level had dropped about 1cm after about 400 miles, the smell seemed to come from the back. Does this point to the same kind of problem?

Gaffers
The ECU temp sensor is also at the back. Two sensors 1 for the gauge with just 1 wire going to it & t'other with a 2 pin plug on it that talks to the engine ECU.
Title: Re: Temerature gauge
Post by: Gaffers on 06 March 2007, 21:34:37
Quote
Quote
I wonder if I have a similar problem.  My ecu light has been on for a bit now and the code states temp sensor voltage low.  I also got a faint smell of coolant yesterday for about 2 minutes.  So I stopped popped the bonnet, coolant level had dropped about 1cm after about 400 miles, the smell seemed to come from the back. Does this point to the same kind of problem?

Gaffers
The ECU temp sensor is also at the back. Two sensors 1 for the gauge with just 1 wire going to it & t'other with a 2 pin plug on it that talks to the engine ECU.

Does anyone know how much they are from Vx? Or if there are any good alternatives out there?

Gaffers
Title: Re: Temerature gauge
Post by: AndersH on 08 March 2007, 08:30:32
Quote
Driving car today had covrd about 50 miles, car running fine...all of a sudden temp gauge shoots up to 100c+ and then drops suddenly back down again (too quick for it to be fan cutting in?). Then starts to behave very erratically up and down the gauge first red hot then back to normal.

Mine used to do something similar when stuck in traffic, it would go right into the red and a warning light would come on, after 5-10 seconds or so it would shoot back down to 90 ish then slowly creep back up again. I then found that 2 30 amp fuses had gone in the engine bay near the relays which were hidden under a load of wires! seems to be fine now although haven't been in as bad traffic since, but the temp is much more stable now.
Title: Re: Temerature gauge
Post by: Gaffers on 08 March 2007, 09:17:33
Quote
Quote
Quote
I wonder if I have a similar problem.  My ecu light has been on for a bit now and the code states temp sensor voltage low.  I also got a faint smell of coolant yesterday for about 2 minutes.  So I stopped popped the bonnet, coolant level had dropped about 1cm after about 400 miles, the smell seemed to come from the back. Does this point to the same kind of problem?

Gaffers
The ECU temp sensor is also at the back. Two sensors 1 for the gauge with just 1 wire going to it & t'other with a 2 pin plug on it that talks to the engine ECU.

Does anyone know how much they are from Vx? Or if there are any good alternatives out there?

Gaffers

Just found out, around £10 from Vx
Title: Re: Temerature gauge
Post by: devonian on 10 March 2007, 22:37:27
Well have been doing some miles in the car this week and temp guage behaving normally....when it did happen, missus was driving  ::) she decided it would be a good idea to try out an emergency stop....it was right after this that the guage started to act up  :-?...so does look like Marks theory of a short with the wire....