Where does the temp gauge point?

[Joe Harding]

On my 1.4, the temperature gauge reaches about a third of the way along the scale. Anybody have a car that runs hotter? Car runs okay BTW

[Clan]

Originally Posted by Joe Harding

On my 1.4, the temperature gauge reaches about a third of the way along the scale. Anybody have a car that runs hotter? Car runs okay BTW

It should be vertical , if it is an early 300 say up to 1984 with a SMITHS dash it is likely to be the sender but if a later VDO dash then go for the thermostat .

[Joe Harding]

I did change the thermostat, I checked it opened well above boiling point but same result. It's not crucial, just sussing out other results

Thanks

[macplaxton]

Slap bang in the middle on my car.



Happily running a 92°C stat

[foggyjames]

I've always had terrible trouble with temp gauges in the early cars. I haven't used the '79 silver one enough to remember whether or not it behaves itself, but I seem to remember that the '81 car wouldn't sit in the right place before the engine swap (and now there is no suitable sender for it in the head...but I'm working on it!), and the temp gauge in the '80 345 was first reading cold, and is now completely dead. Seems to be a weak point, or I have foul luck.

cheers

James

[macplaxton]

I've got a good temp sender for a Smiths, but it's a single tag thing. I suppose the way round it would be a T-piece for a separate warning light sender.

[Clan]

I think there are 3 types of sender :
1 , the early 343 up to 1981 had a two pin sender , SMITHS instruments , one tag was a switch for the low fuel warning light and the other a normal variable resistor for the temperature gauge .

2, from 1982 to around 1985 they had a "multifunction switch" plugged into the back of the SMITHS instrument panel. this had the single terminal smiths sender .These could play up and leave the high temp or low fuel warning light or the fuel gauge playing up .

3, after about 1985 they went to VDO instruments which used the temp gauge itself to work the warning light and had a single terminal VDO sender.

faults with low readings on the early twin sender are caused by internal resistance inside the sender i have opened up a few and cleaned the contact points inside, re sealed and they have worked fine again ..

from 1981 they still had a smiths instrument panel, which resembled the later VDO , cars had both of these so you had to determine which was SMITHS or VDO .

[foggyjames]

Is it a quick job to demonstrate the repair procedure? If so, I'll bring my spare one down with me when I drop the amp off, if you'd be kind enough to show me the ropes?

cheers

James

[Joe Harding]

Originally Posted by Clan

I think there are 3 types of sender :
1 , the early 343 up to 1981 had a two pin sender , SMITHS instruments , one tag was a switch for the low fuel warning light and the other a normal variable resistor for the temperature gauge .

2, from 1982 to around 1985 they had a "multifunction switch" plugged into the back of the SMITHS instrument panel. this had the single terminal smiths sender .These could play up and leave the high temp or low fuel warning light or the fuel gauge playing up .

3, after about 1985 they went to VDO instruments which used the temp gauge itself to work the warning light and had a single terminal VDO sender.

faults with low readings on the early twin sender are caused by internal resistance inside the sender i have opened up a few and cleaned the contact points inside, re sealed and they have worked fine again ..

from 1981 they still had a smiths instrument panel, which resembled the later VDO , cars had both of these so you had to determine which was SMITHS or VDO .

Good information, thanks. So in your opinion, what would be the most likely reason for a low temp reading on a 1987 340? I have swopped the thermostat with no success and checked opening temps (about 90 deg) Do the engine temp transducers go high resistance?

Or is there another possibility that with a new radiator, fully flushed system with a good strength antifreeze I simply have too efficient a cooling system? I mention this because in hot weather and standing traffic, the fan does sometimes come on and the temp gauge rise above mid-position.

[macplaxton]

Originally Posted by Clan

one tag was a switch for the low fuel warning light and the other a normal variable resistor for the temperature gauge.

I understand what you mean, but did you not mean to write "high temperature"?