8 replies to this topic

[fyb]

1982 998CC

The temperature gauge moves into the red after a few minutes of driving. The engine has been checked and isn't be running hot. When the lead is disconnected from the sensor the gauge drops to zero.

Has anyone else experienced this problem and what was the outcome i.e was it the gauge, the sensor or a wiring problem?

Edited by fyb, 14 May 2011 - 12:39 PM.

[Brigbeale]

If you are certain that the engine isn't running hot, it will almost certainly be the temperature sender gone faulty and you need a new one.

If you touch the wire connector on engine block, the needle will red-line.
The sender is essentially an heat operated switch which gradually earths the supply on that wire.
They sometimes go open circuit (needle stays at bottom) or short circuit (needle goes to top of guage).
Other times they will not read accurate (show cold at start and then quickly 'over-read' the actual heat of the engine.

Either way, replace it.
First note which connection is on the end of it (flat blade or round pin).
Get the new on and check the connector. Usually, they will be the same, but if they are different, (new ones are generally flat blade type), you will need to change the wire connector as well.

[dklawson]

In addition to the above advice... is the fuel gauge working OK or does it also seem to read "high"?

[fyb]

Thanks for the advice will try the sender unit as suggested.

Edited by fyb, 15 May 2011 - 05:54 PM.

[fyb]

The fuel gauge appears to be working fine so will try the sender unit.

[ibrooks]

The gauge and the sender are a matched pair aren't they? If someone has been plaing mix and match they might be working as they should but have mismatched resistance scales.

Iain

[Big_Adam]

The gauge and the sender are a matched pair aren't they? If someone has been plaing mix and match they might be working as they should but have mismatched resistance scales.

Iain

Electrical no, mechanical ... no idea. That's if we're talking stock parts and years.

[dklawson]

Electrical no, mechanical ... no idea. That's if we're talking stock parts and years.

Mechanical... no. The mechanical gauges don't have separate sending units.

Electrical, maybe. There are several different sending units. I cannot tell you which sender goes with which gauge but there are several to choose from and if you get the combination wrong, you can get incorrect temperature readings.

[ibrooks]

The question was to the OP to establish whether or not he did have a matched pair (sender and gauge).

Since he was talking sensors and wiring I assumed we weren't looking at a mechanical gauge. In a mechanical setup there isn't a sender as such but a capillary tube and a bulb.

There are hundreds of senders with different resistance ranges and as many different gauges. Many of them we can discount as they are highly unlikely to be used in a Mini but there are enough different parts that will fit relatively easily that it's worth asking the question. If we're looking at standard Mini parts then the chances are that they should work together but if as I said someone has been playing mix and match then there's no telling what they will do together.

Iain