Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: alpacino on 13 September 2010, 17:26:02

Title: temp gauge rising..then falling
Post by: alpacino on 13 September 2010, 17:26:02
Hi i have a 2.5 v6 preg omega...i noticed my temp gauge rising to below 100 and when i accelarated it went to 95 this happened a few times.
i also had coolant level on screen after this happened ... any ideas pls ?? and how do i diagnose the problem :'(
Title: Re: temp gauge rising..then falling
Post by: tango on 13 September 2010, 17:28:44
check if you have enough coolant in the system
turn car of let it cool down then fill up to the line on the header tank
if you are losing coolant then check for leaks
Title: Re: temp gauge rising..then falling
Post by: alpacino on 13 September 2010, 17:32:26
yer loads of coolant...im just worried it might be water pump ....expensive job
Title: Re: temp gauge rising..then falling
Post by: aaronjb on 13 September 2010, 17:36:08
I'm not quite clear from your original message;

Does it rise to 100 while you're accelerating and then return to 95 when you're back to cruising normally or does it rise to 100 when you're cruising and then go back to 95 when you're accelerating?
Title: Re: temp gauge rising..then falling
Post by: tango on 13 September 2010, 17:59:18
Quote
yer loads of coolant...im just worried it might be water pump ....expensive job
water pump is cheap about £35
doing is it not hard but time consuming
Title: Re: temp gauge rising..then falling
Post by: alpacino on 13 September 2010, 18:39:11
sorry...when im idle at traffic light etc its on 98ish just below 100

when i accelarate off it drops down to approx 92/95

Title: Re: temp gauge rising..then falling
Post by: whippit on 13 September 2010, 18:47:22
Sounds very much like a knackered viscous fan but I dont know if this model even uses one LOL
Probably a lazy temp switch on electric fan.
What temperature does the fan kick in at and does the temp start to drop immediately it does?

Typical for temp to drop when accelerating as increases air flow around radiator
Title: Re: temp gauge rising..then falling
Post by: davethediver on 13 September 2010, 18:57:58
Quote
Sounds very much like a knackered viscous fan but I dont know if this model even uses one LOL
Probably a lazy temp switch on electric fan.
What temperature does the fan kick in at and does the temp start to drop immediately it does?

Typical for temp to drop when accelerating as increases air flow around radiator

Sounds like coolant loss to me ::) ::) have you checked the HBV and all the normal culprits hoses etc ;)
Title: Re: temp gauge rising..then falling
Post by: PhilRich on 13 September 2010, 19:01:40
Quote
Sounds very much like a knackered viscous fan but I dont know if this model even uses one LOL
Probably a lazy temp switch on electric fan.
What temperature does the fan kick in at and does the temp start to drop immediately it does?

Typical for temp to drop when accelerating as increases air flow around radiator










And the waterpump turns faster, thereby circulating the coolant quicker & providing engine cooling (as it should), so perhaps the pump is OK & the temp sender in the block needs looking at? :-/ :y
Title: Re: temp gauge rising..then falling
Post by: Teebee on 13 September 2010, 20:08:32
You are getting the coolant warning but are you actually losing coolant, do you need to top it up after this happens? I'm wondering if it could it be air in the system?

On a side note my f/l that just blew up used to sit at 85 all day, my mfl which i've owned for eons always sits at 95. What i'm trying to say is has anything changed that makes you think it is now a problem?
Title: Re: temp gauge rising..then falling
Post by: alpacino on 13 September 2010, 21:36:27
the only things that have changed is i top it up more often and that temp gauge rises more than ever....thinkin thermostat too??
Title: Re: temp gauge rising..then falling
Post by: Smiddy on 13 September 2010, 22:20:01
I have exactly the same problem! Gets just under 100 when driving around town then the fan kicks in and it drops a bit. Driving a bit quicker (about 60) and it drops down to 95.

It doesnt really seem to loose coolant though, saying that I havent driven it a lot because the wheel bearing needs doing.

Going to have a better look at the weekend while doing the wheel bearing and changing the header tank.
Title: Re: temp gauge rising..then falling
Post by: harpersimon on 13 September 2010, 23:25:19
check the coolant cap, and neck of the coolant tank. They can let air in (mine had hairline cracks around the coolant tank neck) and when air gets in the coolant temp cannot be maintained unless its being pumped around. Temp will rise and fall only controlled by movement and the fans. Both parts are cheap and worth looking at before ripping the engine apart to get to the water pump (which isn't a massive job but more involved)
Title: Re: temp gauge rising..then falling
Post by: Kneepad on 13 September 2010, 23:31:34
Quote
the only things that have changed is i top it up more often and that temp gauge rises more than ever....thinkin thermostat too??

You're not going to get any further with this until you find
the leak. If you have to keep topping up then you are losing coolant. Don't think thermostat. Have you checked all the hoses and the HBV, radiator, heater matrix.

Take the car for a drive, get down and look underneath for drips.   :y
Title: Re: temp gauge rising..then falling
Post by: Smiddy on 13 September 2010, 23:33:43
Thanks for that simon, I thought that was what it might be, mine has hair line cracks as well in the same place, Dave is sending me another bottle tomorrow, hopefully that's all it is  :y
Title: Re: temp gauge rising..then falling
Post by: alpacino on 14 September 2010, 15:44:41
thanks ill try that, also like to add on a previous post i had water leaking in on passenger side....thats never happened again
Title: Re: temp gauge rising..then falling
Post by: harpersimon on 14 September 2010, 21:52:35
Quote
Thanks for that simon, I thought that was what it might be, mine has hair line cracks as well in the same place, Dave is sending me another bottle tomorrow, hopefully that's all it is  :y

mine would go up and down and when I came to a standstill it would practically full the expansion bottle, as it was expanding too fast i.e boiling due to no consistent pressure = replaced the coolant tank, problem solved.