Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: nuclear onion on 08 November 2013, 10:06:18

Title: Engine running cold
Post by: nuclear onion on 08 November 2013, 10:06:18
Hello
I have a 52 plate, 2.2 saloon and according to the temp gauge, it runs way colder than it should. It also takes quite a while from starting up until the needle even begins to move. Basically it hovers around the first notch and occasionally will get up to the 80 mark but quickly comes back down again. The general opinion is the obvious stuck thermostat but knowing these cars as we do, it occurs to me there could be other possible causes I may need to investigate. Could somebody tell me if there is anything else I should look for or is it a fairly safe bet its just the thermostat?
Any help would be appreciated  :)
Title: Re: Engine running cold
Post by: Entwood on 08 November 2013, 10:16:04
Start engine from cold and leave to idle, with the heater turned OFF, whilst standing with one hand on the LARGE pipe from the thermostat to the top of the radiator....

If the pipe very gradually warms up the thermostat is stuck open and requires changing.

What SHOULD happen with a serviceable thermostat is the pipe stays cold until a sudden surge of HOT (not warm) water passes along it as the thermostat reaches heat and opens.

My betting is you get the gradual warming .. change the thermostat .. :)
Title: Re: Engine running cold
Post by: zirk on 08 November 2013, 10:18:08
Is it blowing hot air from the heater when its warm? could be temp sender?, more likely to be Thermostat though, typical symptoms of a stuck or open Thermostat is temp rises when stationary or stuck in traffic, then starts to cool down again when on a drive or motorway run.

Take it your coolant level is ok?
Title: Re: Engine running cold
Post by: nuclear onion on 08 November 2013, 10:24:23
It blows warm air into the cabin but I wouldn't exactly call it hot. Even with the heater set on it's highest setting the air coming into the car isn't as hot as I'd expect it to be. Checked the coolant level and it's just where it should be.
Title: Re: Engine running cold
Post by: Field Marshal Dr. Opti on 08 November 2013, 12:55:34
I have this problem on my V6, which I've ignored because the thermostat is a bitch to get to. :'( :'(

I believe that access to the stat is much improved on the 'junior' Omega.... ::) ::) ::) ;D
Title: Re: Engine running cold
Post by: nuclear onion on 08 November 2013, 13:03:51
Start engine from cold and leave to idle, with the heater turned OFF, whilst standing with one hand on the LARGE pipe from the thermostat to the top of the radiator....

If the pipe very gradually warms up the thermostat is stuck open and requires changing.

What SHOULD happen with a serviceable thermostat is the pipe stays cold until a sudden surge of HOT (not warm) water passes along it as the thermostat reaches heat and opens.

My betting is you get the gradual warming .. change the thermostat .. :)
You were right. Gradual warming. Thanks for the help  :)
Title: Re: Engine running cold
Post by: Entwood on 08 November 2013, 13:31:40
Start engine from cold and leave to idle, with the heater turned OFF, whilst standing with one hand on the LARGE pipe from the thermostat to the top of the radiator....

If the pipe very gradually warms up the thermostat is stuck open and requires changing.

What SHOULD happen with a serviceable thermostat is the pipe stays cold until a sudden surge of HOT (not warm) water passes along it as the thermostat reaches heat and opens.

My betting is you get the gradual warming .. change the thermostat .. :)
You were right. Gradual warming. Thanks for the help  :)

Thermostat failed open, system never gets hot as it is "overcooling" which will get worse as winter temperatures drop. You can't get heat out of a cold system !! The engine running cold will also make the fuel economy worse !!

Time for a thermostat change ..  :y :y :y
Title: Re: Engine running cold
Post by: 05omegav6 on 08 November 2013, 15:16:05
Finally doing mine on sunday ::) currently a woeful 22mpg :-\
Title: Re: Engine running cold
Post by: nuclear onion on 08 November 2013, 15:27:02

[/quote]

Thermostat failed open, system never gets hot as it is "overcooling" which will get worse as winter temperatures drop. You can't get heat out of a cold system !! The engine running cold will also make the fuel economy worse !!

Time for a thermostat change ..  :y :y :y
[/quote]

Its due for a coolant flush/change anyway so I can kill two birds with one stone