Indy just replaced sending unit on my 74' 2.0 He replaced it because gauge was not registering any temp. Drove 20 hwy miles today in 80 degree weather. Oil temp never got above 150 degrees. That can't be accurate - can it?

Which sender?

Click to view attachment

Neither - this one Click to view attachment

Did you match that gauge with the correct sender? If not it will not be accurate.

Also, where are you located in MD?

Yeah, that's aftermarket VDO. They have specific senders for specific gauges, two different ones as I recall.

Oil temp staying at 150F is not expected, especially in summer.

The indy said he spoke with VDO about what he needed however i'm suspect...particularly given this indy:-(

Indy is suggesting that maybe the engine didn't have chance to reach temps in 20 miles in 80 degree weather - uggh

I'll follow up with indy to verify that gauge and sender match.

Give it a longer drive first. 150F may be normal after only 20 minutes. Give it a good 30-40+ and see where it stabilizes.

I have an external cooler with a 180F physical thermostat, and I measure the oil temp in the cooler lines. I'm skeptical that it takes 20 minutes, but it does take a good chunk of minutes before I start to see an oil temp indication above ambient.

Sorry. Drive was 20 miles...about 35 minutes

They supposedly matched gauge and sender but I'm not confident indy actually did. Digging into that now.

I'm close to you...located in Woodbine.

Where is the sender located?
Is the top portion exposed to airflow? That can give false low readings.
Do you have an infra red heat gun to chech the temp?

I’ll need to check that. Ty