temp sendor

[Matthieu]

hi volvo people
I was trying to install a temp guage as the stock one doesn;t work So I removed the temp sender which is closer to the front of the car beside cyl 2 . there is oil in the hole and all over the sender. Could this be the coolant temp sender or is this the etc for the fuel injection . I am confused. I didn't remove the one nearer to the fire wall because they are so darn tight. Please help me find out which is for coolant temp if you can
thanks
Matt
89 740gl wagon b230f regina /rex

 

[Three Fat Tigers]

If you pulled this sensor out of the left (driver's side) of the engine, you have more serious problems than a gauge that doesn't work, there should be no oil present on any sensor located on that side of the engine. If you pulled this out of the right side of the motor, you just removed the oil pressure sensor.

The temp gauge sensor is located in the cylinder head under intake manifold runner number two (the number one runner being the runner closest to the front of the car), it has two wires. The LH fuel injection coolant temp sensor is located in the cylinder head under runner number three, it also has two wires but contains two sensors internally.

 

[CheezyFish13]

Just wondering but how long has ur gauge not worked....mine hasnt worked since 1993 (worked for only 2 years) same with the seat warmers. The temp just jumps up and down randomly...it sux not knowing when u are about to overheat...

how often of a problem is the temp gauge?

 

[Three Fat Tigers]

Just wondering but how long has ur gauge not worked....mine hasnt worked since 1993 (worked for only 2 years) same with the seat warmers. The temp just jumps up and down randomly...it sux not knowing when u are about to overheat...

Your car was still under warranty, why didn't you get it fixed?

On your 240 odd are you may simply have a problem with the temperature compensating board on the back side of the instrument cluster. Try cleaning the contacts there, or bypass it.

To test the temp sensor circuit, pull the single wire off the single wire sensor at the cylinder head under the intake manifold and touch/jumper that to ground. The gauge should move to the top of the gauge. Then connect a 68 ohm resistor between the sensor wire and ground, the guage should move up to the 3/4 position on the scale. If not the gauge is faulty and needs to be replaced. If the gauge passes both tests, the sensor is faulty.

 

[Matthieu]

response

I did remove the right sender but . I have to find out why the oil . The gauge always reads half mark even when the car is boiling and overheating.
thanks for all the help.
Matt

 

[CheezyFish13]

yes we did take it in to the shop
they tried all that they could to fix it and never go anywhere
as i recall it worked for like 3-4 months on and off and then eventually just stopped working
it got serviced with both the seat warmers and the temp gauge on many occasions..we just sorta gave up after a while

ill try and test the circuit like u said

 

[Three Fat Tigers]

I did remove the right sender but . I have to find out why the oil .
Matt

The right side sender is the OIL PRESSURE SENDER, it is supposed to have OIL all over it, this item has nothing to do with the COOLANT temperatures or any part of the COOLING SYSTEM.

Now if you meant right as in correct, then the oil is a bad sign, likely you have a head gasket problem, this would account for the over heating as well, though you should also see signs of oil or oil related sludge in the coolant reservior.

The gauge always reads half mark even when the car is boiling and overheating.

There you may have a faulty coolant temp sensor, try removing that one instead