Car is UNDERheating , temperature gauge reading stays very low, why ?

[Rightboy91]

Car is a Vauxhall Vectra C 1.9cdti 120 bhp.

Over the last week or so I noticed the temperature gauge barely moves from the very bottom and once it does it never goes above 80 which ise near bottom on the temperature display .
Before this the temperature gauge would behave normally, when sat in traffic it would go to about 90 degree then cool once driving again and the gauge would be accurate during all other diving circumstances.

Since I noticed the temperature gauge barely moves and stays below 80 degree I've realised something else tonight, the engine even after long journeys of over 50 miles doesn't seem half as hot, I can actually lean on the engine without the inlet manifold burning me , it's usually red hot after the car has had a decent run.


I did replace the front metal cooling pipe about 3 weeks ago the long pipe that runs the length of the engine at the front but after fitting it the temperature gauge was fine that was about 3 weeks ago, this issue has only been happening for about 1 week.

Any ideas ? Thanks

 

[Harry Bloomfield]

Reaches for popcorn....

 

[Burnerman]

Either the thermostat is stuck open or missing altogether.
John

 

[HERTS P&D]

Here we go again...................................................

Andy

 

[Harry Bloomfield]

This 'car' needs a mechanic permanently riding shotgun in the passenger seat.

 

[Rightboy91]

This 'car' needs a mechanic permanently riding shotgun in the passenger seat.

Either the thermostat is stuck open or missing altogether.
John

Hi John, thanks for this.

So would a stuck thermostat cause notnonly the temperature gauge to barely move but also cause the entire engine to remain very cool even after long journeys ? It doesn't even get hot to the touch.

2 - could it be an airlock or anything to do with me changing the long metal cooling pipe a few weeks previously ? The thing is ,the temperature gauge was working fine 2 weeks after changing the pipe up until about a week ago.

3 - what did you mean by asking if the thermostat is still present ? If not the water would be pouring out of the engine and the car would be out of water within a minute

 

[Mottie]

This 'car' needs a mechanic permanently riding shotgun in the passenger seat.

Urgh! You don’t know what’s been going on in the passenger seat of that car!

 

[HERTS P&D]

Andy

 

[HERTS P&D]

The 'car' that keeps on giving!



Andy

 

[Mottie]

Sounds like the sort of car I’d put a seat cover on to keep my overalls clean!

 

[JohnD]

This 'car' needs a mechanic permanently riding shotgun in the passenger seat.

Not "shotgun."

Humane killer.

 

[JohnD]

3 - what did you mean by asking if the thermostat is still present ? If not the water would be pouring out of the engine and the car would be out of water within a minute

no it wouldn't. There is no hole for it to pour out of. It would be circulating very freely, losing more heat than usual to the radiator, so would not get up to normal running temperature quickly, if at all, now the weather is getting cold.

 

[Harry Bloomfield]

It would be circulating very freely, losing more heat than usual to the radiator, so would not get up to normal running temperature quickly, if at all, now the weather is getting cold.

Or simply stuck wide open.

 

[JohnD]

yes, but thermostats are fairly reliable.

Unskilled people do sometimes take them out if the vehicle is overheating.

Such a person may previously have had their hands on this car.

 

[Harry Bloomfield]

Such a person may previously have had their hands on this car.

Such a person still has his hands on this car )