Temperature gauge issues

[Lecozens]

Hi all,

Driving to Peterbrough today I learnt something amazing about my car. Apparently I have the best cooling system ever. Even in the heat of today and driving for 2 hours my temperature gauge never moved more than half a cm.

I'm assuming therefore my marina is either amazing or broken. Am I right in thinking its either a thermostat issue or the temperature sensor?

Both bits seem easy to fit however would I need to rewire the sensor? If so how would I go about that?

Thanks in advance

Lewis

[timspencer]

Nice to meet you both today mate, lovely car and those seat covers are awesome

Maybe she just kept cool?

My sd1 has never overheated in 20 years and never gets one half way?

Still a good flush and a new thermostat won't hurt.

[david painter]

Does your heater get hot? If yes you got a gauge issue. If no you have a thermostat issue. The Gauge can easily be checked, switch on ignition pull wire of sender and short it to earth, should go up into red if doesn't move gauge is faulty. Next question does fuel gauge work correctly. If yes Voltage stabaliser is ok. You have a gauge/wiring issue. If heater gets hot and gauge works correctly on test replace sender unit ensuring correct part fitted, not just one that screws in the head. The coloured ring on it is the calibration identification. Don't just assume that because you have a pink one fitted that is correct application for car, it may have had the wrong one fitted previously. Check it against your chassis no, in the parts book. For More Cooling System information see my posts in ( Its All About the Timing ) while on the subject of cooling systems and over heating. Remember when A plus was introduced in the Ital there was shielding around the radiator to direct more are over radiator core rather than around it and a Viscous fan was fitted so it only cut in when needed and freewheeled when not needed as sort of mechanical electric fan! Something like this shieling could be made and would vastly improve the efficiency of the cooling system.
Dave

[Lecozens]

Cheers both,

Tim you broke my heart a little, I was quite looking forward to seeing cora

I will be doing a flush this week, was going to happen before this.

Fuel gauge works, it constantly reminds me I need to buy more petrol. I won't lie, I am a complete car novice. What does short to earth mean and how do I do it?

[timspencer]

Sorry Lewis, trust me I was gutted!

We only live 25 miles apart mate so I'm sure we can get the two harvest gold cars together!

[david painter]

Earth is the side of the battery that is connected to the body, not the starter. In 99% of the cases its Negative earth, some very early Dynamo equipped cars may have been positive earth. This was generally phased out by 1970. All most of the remainder has subsequently been swapped to negative. What I mean by earthing out sender wire is pull it off the sender and hold it to a piece of good clean metal. Alternator mounting bolt is usually very handy on A & B series engine, when it held against bolt temp gauge needle should go to top of the red. The Sender works by as the engine gets hotter is has less resistance in it, meaning gauge needle goes up as engine heats up.
Dave

[Lecozens]

Thanks David, I will give that a go tomorrow. Just to make sure I understand fully, take of the sender (electrical cable) off the sensor, put it on to a peice of clean metal attached to the car whilst the engine is running? If it goes all the way up, sensor is the issue if it doesnt then the cable is the issue? How easy is it to replace the wire?

[Lecozens]

Ps Tim, it's Lewis not Lee

[david painter]

You only need ignition on take wire off and hold it on metal. If gauge goes up its sender, if not Gauge /wire fault and further diagnosis will be required. You must get car properly warmed up first and see if heater blows hot ar. If it only blows cold of luke warm, you have an engine issue.Usually a thermostat stuck open.You should sort this if you have a problem and get it working correctly, before worrying about the gauge.
Dave

[timspencer]

Doh! Apologies.

Too much sun!