Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Pawel_Nottingham on 08 October 2011, 18:10:23

Title: Temperature fluctuations in 3.0 v6
Post by: Pawel_Nottingham on 08 October 2011, 18:10:23

Hi,

Does anyone know why does my temperature gauge drop suddenly when I'm reving up the engine? As soon as I take my foot off the accelerator it comes back to normal.

For example today: Gear 2, 1500rpm, Temperature:92. I floored it to 6000rpm and within 5-10 seconds temperature dropped to the point a gauge was lying flat. After another 10 seconds it came back to 92 Celsius.
I was able to recreate this situation numerous times. Does that with heating set to HI as well as set to LO and a few in between, doesn't matter if I'm driving or standing still.

Thermostate was replaced in December 2010 and so was the water pump with a new timing belt set.

This car had a problem with coolant disappearing for many years, approx 1 litre per 1500miles, but recently it loses 1 litre every 2-3 days regardless of the mileage. I found a small crack in the radiator, but I don't know how much is that related to temperature jumps?

Please don't tell me the car is dying ???

Title: Re: Temperature fluctuations in 3.0 v6
Post by: General Melchett on 08 October 2011, 18:38:54

I am not 100% sure and you would need more tests to diagnose properly but it sounds suspiciously like HG failure.  The reason I am hesitant is that it is very rare on these engines but if you have been running it without enough coolant it could have warped the heads..

While reving fill the expansion tap and see if there is water or air coming from the radiation pipe feed.  You can also whip off the plugs and check for moisture but the best test you can do is a pressure test or a sniff test.

I hope for you that it isn't

Title: Re: Temperature fluctuations in 3.0 v6
Post by: albitz on 08 October 2011, 18:53:07

I would be checking the water pump.

Title: Re: Temperature fluctuations in 3.0 v6
Post by: Pawel_Nottingham on 08 October 2011, 19:15:02

General Melchett - pressure test was done 2 days ago and went fine - sorry, forgot to mention this.

Albs - even if it was replaced only 10 months ago? Genuine Vauxhall part as well.

Title: Re: Temperature fluctuations in 3.0 v6
Post by: joff on 08 October 2011, 19:24:03

Have you checked the heater bypass vavle at rear of engine

Title: Re: Temperature fluctuations in 3.0 v6
Post by: Pawel_Nottingham on 08 October 2011, 19:46:12

No I haven't, but it has been replaced in 2009. Coolant was leaking whenever I set the climate control to LO.
Do you think it's failing again?

Title: Re: Temperature fluctuations in 3.0 v6
Post by: joff on 08 October 2011, 20:26:00

Do you use Vauxhall parts when doing work on the Mig  ???

Title: Re: Temperature fluctuations in 3.0 v6
Post by: Pawel_Nottingham on 08 October 2011, 21:52:36

I mostly use Vauxhall parts although HBV was not genuine.