The gauge is stuck, stuck, stuck, stuck, help, help, help,he

[sloopjohnrb]

Hi, it's my nephew's Puma, R511 XCU, 1.7, and I have another query.

we got the car about 2-3 weeks ago, and it's a good 'un, FSH etc.

The previous owner explained that the temp gauge was constantly stuck on red virtually since he bought it new.
This proved to be right as I drove it back from Little Hulton to Wales.
If the gauge was accurate, the engine would have melted down years ago.

The engine doesn't overheat, the coolant doesn't drain rapidly and the fan isn't always on and, indeed, all seems well.

I wanna' fix this gauge problem as-one day it could be reading accurately viz engine temp and nobody would know.

My questions are:
1 Is it the Thermostat and if so, do I need to replace the Thermo housing as well as the Thermo?

2 Is it the HCV?

3 Could it be both?

Any help, MOST gratefully received as I run a 1962 Morris Minor (much to the embarrassment of Joseph, my nephew!) and usually work on my car, my sister's Micra, and Joe's old Clio-the Puma is just sooo different.

 

[XIIVVX]

I think thermostats generally fail safe (ie overcool the engine rather than overheat it)

Certainly always used to be the case.

 

[sloopjohnrb]

Hi, if it's not the thermo, then is it the HCV?
As I mentioned, the engine is not over hot and runs at normal temperature.
The heater works fine too.

By the way, it's had an oil change and new filter, cooling system drained and flushed,along with new air filter and plugs.

Should I be looking at temperature senders, replacement gauge and stuff?

 

[red]

Hi John,

A #1 indicator of a faulty HCV is that the fans either only blow cold or only blow hot; do you have these symptoms?

I hope get it fixed

 

[sloopjohnrb]

Hi, I'll check this first thing tomorrow-by the way, when one gets into the car and just turns on the auxiliary system, the gauge goes straight to "Hot", even when the car's been stood overnight and the engine is stone cold. This is before the engine has turned.

The car can be left for days, yet when the auxilliary ignition is turned on the gauge goes to hot rather like a putrol gauge dous when one has a full tank. Again, the engine has not fired.

Does this provide a clue?

 

[XIIVVX]

Faulty gauge or sender would be my initial diagnosis.

That definitely rules out thermostat and HCV.

 

[red]

Yeah doesnt sound much like the HCV.

 

[sloopjohnrb]

Wow, thanks all-it would have been expensive to buy both HCV & Thermo and then find out it's either gauge or sender.

Err, I'm not sure what a "sender" is...where would I find it?
Bes-t wishes