Oil temperature gauge

[5UG]

I'm having problems with my Spider Oil temp gauge.
It doesn't move off the minimum reading even after a good drive.
The sender unit is brand new (Centerline), and there's a new wiring loom.
The gauge was tested and gave a maximum reading when wired independently.
What should a normal reading be, is it possible that evrything's working but the oil temp is too low to make the gauge needle move?
Alternatively might the new sender unit not be working?
Or is there something else which could be causing the problem?
Thanks
Alan

[divotandtralee]

Quote:

Originally Posted by 5UG I'm having problems with my Spider Oil temp gauge. It doesn't move off the minimum reading even after a good drive. The sender unit is brand new (Centerline), and there's a new wiring loom. The gauge was tested and gave a maximum reading when wired independently. What should a normal reading be, is it possible that evrything's working but the oil temp is too low to make the gauge needle move? Alternatively might the new sender unit not be working? Or is there something else which could be causing the problem? Thanks Alan

[Gubi]

There are different senders with different resistance ranges, so maybe that's the problem. Your gauge may also be in need of calibration. Start by measuring the sump temperature with an IR thermometer to get some idea of what the temperature really is, then you'll know if the gauge is really off.

Are you a member of the 750-101 Yahoo group? There are documents with details on the sender resistances and gauge calibration in the Files section. Suggest joining.

alfaromeo750-101 : A discussion group for owners of Alfa Romeo Type 750-101

[jkbartusek]

Does your new wiring loom include the resistor?

Joe

[Gubi]

The resistor is only 20ohm so in practice it makes minimal difference.

[divotandtralee]

5UG, I sense your frustration. I have stuff on my Fulvia that should work but doesn't and it drives me batty ( or as you say bonkers?).. . It is interesting to note there is no specified range in the manuals for oil temp but there is for oil pressure and water temp and every other measured liquid or current bearing device. Then, additionally, the identical circuit for oil temp has a resistor in circuit and the water temp circuit does not and both gauges appear identical, as do the senders. That's why I said, "relax". There are more important things to get right than this one. I have only registered an oil temp on my 1960 SZ and 1957 Spider Veloce when I was driving 90 MPH and the ambient was over 105F in Kansas.... which is sort of like Iraq in July.

[5UG]

Thank you guys.
Believe it or not this is the last piece of the jigsaw in the nut and bolt restoration.
The car is just about perfect, everything else works, so it would be quite nice to finish the job off.
I wondered about the resistor (as it hasn't got one fitted) but understood that the only purpose was to dampen the needle movement, but maybe not.
As the north east of England isn't quite as hot as Kansas, perhaps the oil temperature is always less then 140F, maybe everything is working OK.
I'm a member of the 750-101 Yahoo group so I'll have a look there.

[Andrew]

Have you tested the gauge? Turn the car on, ground the wire at the sending unit to the chassis or engine, does the gauge go to full? If so, gauge is working.
I had the same issue on my Veloce, a new sender from CL and new connector and all was good.
Andrew

[alfazagato]

Now, despite what has been said, the oil gauge will register temperature in the UK. Central London traffic is very much the same as other places and you should see the needle move off the stop after 10 minutes or so in Knightsbridge. Also a good hard drive will also get the needle moving. Yes, use the IR pyrometer to give an indication of the value that should be showing and adjust the magnet positions on the back of the instrument to reflect this. Plenty of info about this proceedure on the 750/101 pages.

[papajam]

Quote:

Originally Posted by 5UG What should a normal reading be,...

[Gubi]

...with a bit of a time delay due to the oil taking longer to heat up. Mine usually reads 165-170 after a long drive on a typical day via IR thermometer of the sump.

[divotandtralee]

Thanks.. you guys have given me the courage to fix mine

[5UG]

Thanks again guys.
I've downloaded the notes from the 759-101 Yahoo group so know what to do.
Stuart are you going to the National Alfa day at Newby Hall?
If you are it would be good to meet you.
Alan

[concept 101]

Alan,

There are small screws on the rear side of the gauge, two per each section, that can be adjusted sidewise when loosend a bit (NOT ALL THE WAY OUT). I have never had a gauge apart, but what I understood is one adjusts positions of the small coils inside the gauge with these screws.

I was in the same situation as you are, measured and tried time after time and everything seemed to work (except the gauge that I made sure wasn´t frosen)), untill I got a tip on this one. Don´t forget to keep the motor warm and ignition on when trying! Then as you carefully move the screws, you should be able to see the needle move as well, just keep in mind to set it accordingly to the oil temperature before you´re done.

Also in my case it was much easier to give it a try, as there´s no windscreen or dashtop in my car yet, so I had good access to the rear of the gauges.

Dennis

[Andrew]

So true re time to temp. Water temp comes up in just a few minutes, oil temp takes a long time, and if you just pot around slowly, never gets very high. Takes some rpm to get a moderate reading.

I just installed a Lucas-bullet type 101 temp sensor in my race Super's 1600 oil filter housing, and a 101 Giulia oil temp gauge on a homemade bracket on its roll cage. Works a treat. See pics on Giulia sedan thread, New Super Track Car.

Working sender, working gauge, 12V to the proper side of the gauge, good ground, good wire from the sender to the other side of the gauge, and it can't not work.
Andrew