Engine Temp Gauge Low?
Thread Starter
Le Mans Master
Joined: Oct 2004
Posts: 8,615
Likes: 60
From: Haymarket Virginia
Engine Temp Gauge Low?
O.k. guys... I'm stumped...
In a 67 the temp gauge is reading low!! I've searched and found if it reads high it possibly is a bad ground at the gauge cluster.
This is what I've done. I've replaced the sender and the gauge.
I've measured the resistance at the sender and it seems to be off.
This is why I say off. I replaced the thermostat and it was a 180. Acording the the chart I got off here it seems to be opening at 140-150
and it never gets hotter than 150-160 after I shut the car off.
Do you guys have any other suggestions?
Thanks!
In a 67 the temp gauge is reading low!! I've searched and found if it reads high it possibly is a bad ground at the gauge cluster.
This is what I've done. I've replaced the sender and the gauge.
I've measured the resistance at the sender and it seems to be off.
This is why I say off. I replaced the thermostat and it was a 180. Acording the the chart I got off here it seems to be opening at 140-150
and it never gets hotter than 150-160 after I shut the car off.
Do you guys have any other suggestions?
Thanks!
Tech Contributor
Joined: May 2005
Posts: 15,576
Likes: 118
From: Conroe Texas
I installed an old sender I had from my 71 oldsmobile vista cruiser, and now the temp gauge reads 180 - just like my IR gun.
Le Mans Master
Joined: Nov 2000
Posts: 7,246
Likes: 21
From: Going too fast over the hill. Iowa
The Wells sender I got at an azone in OK reads 4°-5° higher than the original GM sender that I bagged. Close enough for the low cost. Actually DZVETTE bought it for me on our Power Tour long haul.
Check to make sure the sender is grounded. A lot of people put sealant on the threads - which makes the senders inaccurate.
Check to make sure the sender is grounded. A lot of people put sealant on the threads - which makes the senders inaccurate.
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,926
From: Washington Michigan
Check for corrosion on the terminals inside the multiple connectors on the engine compartment side of the fuse block; the dark green temp sender wire runs through the inboard connector, and if the terminal connection is corroded, resistance will increase, which will show an abnormally low gauge reading. 
Thread Starter
Le Mans Master
Joined: Oct 2004
Posts: 8,615
Likes: 60
From: Haymarket Virginia
O.k. guys... Got an update.
I put back in the "old" sensor it had a larger "tip" than the one I took up.
The OHM readings on are inline with the chart I got.
It reads higher than the one with the skinny "tip" but it's still off!
I measured the resistance on the inside of the car and it's accurate.
I ran a new wire into the car and it didn't change.
Any other ideas?
Thanks
I put back in the "old" sensor it had a larger "tip" than the one I took up.
The OHM readings on are inline with the chart I got.
It reads higher than the one with the skinny "tip" but it's still off!
I measured the resistance on the inside of the car and it's accurate.
I ran a new wire into the car and it didn't change.
Any other ideas?
Thanks
Thread Starter
Le Mans Master
Joined: Oct 2004
Posts: 8,615
Likes: 60
From: Haymarket Virginia
No. I'm going to buy a temp gun today.
But the reading on the meter reads the correct temp according to the chart I got off here.
Does anyone know the differance between the two temp. senders that the vendors supply?
Thanks
But the reading on the meter reads the correct temp according to the chart I got off here.
Does anyone know the differance between the two temp. senders that the vendors supply?
Thanks
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Melting Slicks
Joined: Sep 2003
Posts: 3,050
Likes: 2
From: Orange Ct
Here's what I did. Removed the sensor and suspended it in a beaker so the lower part was under water. Connected the gauge wire and a ground (at a point near where the sensor screws in) to the sensor. Put the beaker on a hot plate and kept close watch on the gauge and the water temp. This tests the whole sysem.
As far as the thermostat. It does not open all the way at the stamped temperature, it just starts to open and is fully open at some higher temperature. Push the thermostat open enough to put a thread or string in the passage. Hang it in a container and when it reaches the opening temp, it will fall off the string to the bottom of said container.
As far as the thermostat. It does not open all the way at the stamped temperature, it just starts to open and is fully open at some higher temperature. Push the thermostat open enough to put a thread or string in the passage. Hang it in a container and when it reaches the opening temp, it will fall off the string to the bottom of said container.