Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: tunnie on 28 May 2013, 14:53:02

Title: Overheating, but no coolant loss?
Post by: tunnie on 28 May 2013, 14:53:02
Had a txt from MotherT to say temp hit red line in the 3.0 Elite Estate, she stopped. Checked coolant, said it was ok  ???

Not actually spoken to her yet to confirm anything, but I'm struggling to think what can cause an over heat with coolant still present other than a blockage somewhere?   :-\

But if that was the case, surely it would burst a pipe?
Title: Re: Overheating, but no coolant loss?
Post by: CaptainZok on 28 May 2013, 14:58:12
Fans working ok?
Title: Re: Overheating, but no coolant loss?
Post by: Jan Suhr on 28 May 2013, 15:01:39
My old 2.2 could act like that on hot days when the A/C were on and when in traffic jams.

Jan
Title: Re: Overheating, but no coolant loss?
Post by: tunnie on 28 May 2013, 15:04:11
Good point will check. Coolant warning light came on, went to 90 then 100+
Title: Re: Overheating, but no coolant loss?
Post by: symes on 28 May 2013, 15:06:37
When mine did that -it was the sensor in rad that was broke :'(
Title: Re: Overheating, but no coolant loss?
Post by: Webby the Bear on 28 May 2013, 15:31:38
Stuck closed thermostat?
Title: Re: Overheating, but no coolant loss?
Post by: Webby the Bear on 28 May 2013, 15:54:49
http://www.youtube.com/watch?v=hUzOTnsWImI

He pressurises the system looking for leaks...so just watch it after 6mins 20secs for overheat diagnosis with no leaks :)
Title: Re: Overheating, but no coolant loss?
Post by: tunnie on 28 May 2013, 16:57:22
Ok, so after 45 mins it started and temp stayed stable. AA man following MotherT back to GrandmaT's were it all ran normally, temp at 85. Lots of revs for 5 mins on driveway, temp remained same. AA said it was sensor fault, not sure myself.

Fans are working, not been in heavy traffic, just approaching a round-about temp shot to 90, then 100.

Coolant level ok.

Very odd   :-\
Title: Re: Overheating, but no coolant loss?
Post by: henryd on 28 May 2013, 17:06:44
Ok, so after 45 mins it started and temp stayed stable. AA man following MotherT back to GrandmaT's were it all ran normally, temp at 85. Lots of revs for 5 mins on driveway, temp remained same. AA said it was sensor fault, not sure myself.

Fans are working, not been in heavy traffic, just approaching a round-about temp shot to 90, then 100.

Coolant level ok.

Very odd   :-\

Be good to get live temp readings off tech 2 as I believe tech 2 uses injection temp sensor rather than the one the gauge uses.
Title: Re: Overheating, but no coolant loss?
Post by: tunnie on 28 May 2013, 17:30:43
Ok, so after 45 mins it started and temp stayed stable. AA man following MotherT back to GrandmaT's were it all ran normally, temp at 85. Lots of revs for 5 mins on driveway, temp remained same. AA said it was sensor fault, not sure myself.

Fans are working, not been in heavy traffic, just approaching a round-about temp shot to 90, then 100.

Coolant level ok.

Very odd   :-\

Be good to get live temp readings off tech 2 as I believe tech 2 uses injection temp sensor rather than the one the gauge uses.

Yeah, MotherT said it was very heavy rain, possible water droplets on rear brass coolant connector causing a short?  :-\
Title: Re: Overheating, but no coolant loss?
Post by: Andy B on 28 May 2013, 18:47:03
....
Yeah, MotherT said it was very heavy rain, possible water droplets on rear brass coolant connector causing a short?  :-\

Shorting the blue wire to the temp sensor would give a 'hot' reading on the gauge.

Has any coolant work been carried out? A passing 'lump' of air going passed the sensor can give strange readings too.
Title: Re: Overheating, but no coolant loss?
Post by: TheBoy on 28 May 2013, 19:55:43
How have you checked the rad fans?

Does the AC work?

If she needs a tech2 on it, get her to swing round when she's back in Brakkers.
Title: Re: Overheating, but no coolant loss?
Post by: tunnie on 28 May 2013, 20:37:02
....
Yeah, MotherT said it was very heavy rain, possible water droplets on rear brass coolant connector causing a short?  :-\

Shorting the blue wire to the temp sensor would give a 'hot' reading on the gauge.

Has any coolant work been carried out? A passing 'lump' of air going passed the sensor can give strange readings too.

No coolant work, but plenum has been off a lot. Needed topping up after that work, but it's done at least 500+ miles since fine. Thanks for suggestion of air lock, did not consider that. Think I'll give it a good coolant flush. It's due one anyway :)

How have you checked the rad fans?

Does the AC work?

If she needs a tech2 on it, get her to swing round when she's back in Brakkers.

Cheers. Fans yes, not sure on A/C, was working last week.

I'm limping estate back home tomorrow, in all next week in Brackley so can pop in :)
Title: Re: Overheating, but no coolant loss?
Post by: omega3000 on 28 May 2013, 21:00:32
My old 3.0 would never overheat at standstill even with the nuts revved off it , on a run it took 5-10 minutes to hit the red zone . Turned out to be a partially blocked radiator  :)
Title: Re: Overheating, but no coolant loss?
Post by: dbug on 28 May 2013, 21:02:32
If its not a sensor, I'd go with a blockage with rad being most likely candidate. ;)
Title: Re: Overheating, but no coolant loss?
Post by: sassanach on 28 May 2013, 21:37:57
radiator :y
Title: Re: Overheating, but no coolant loss?
Post by: cem_devecioglu on 28 May 2013, 21:57:54
I would disconnect the engine from radiator and flush it will lots of lime dissolver (kitchen type)
and keep an eye on the temp gauge for some time..
Title: Re: Overheating, but no coolant loss?
Post by: TheBoy on 29 May 2013, 18:27:32
I'm limping estate back home tomorrow, in all next week in Brackley so can pop in :)
We can give it a ragging test drive, and see whats what.

At this stage, I don't think it is the rad, knowing the car a little, but I am perplexed what it might be.  Wondering if you damaged the insulation when messing around, and thats got wet and shorted to gnd.
Title: Re: Overheating, but no coolant loss?
Post by: adey2 on 29 May 2013, 18:47:28
mine turned out to be the earth lead breaking down, was if it was earthing through the temp sensor, it was consstantly in the red in traffic, but once earth lead changed it never went above 85, well untill belt snapped and missis cooked it