Coolant Temp Sensor
 

Have recently been hunting a problem causing rough cold starts, 2 days ago a check engine light put me on (what i'm hoping is) the right path. Pulled a code, 1-2-3: coolant temp sensor. Bought the sensor, now the install?
have been poking around this morning online and under the hood, but to no avail.
does the code INDEFINITELY indicate a bad sensor? i've been reading a lot about thermostats, draining coolant, etc.
i'm doing my best considering time/money/daylight/temperature constraints.

PLZ HLP!! :)

there are two sensors. 1 is a sender for the dash, the other senses temp for the fuel injection. My gauge sender was broken by some bafoon who wrenched the plastic connector off. The two pin connector replaced, the gauge worked perfectly. BTW, the gauge sender sits just under the intake manifold center. The injection temp gauge is just next to it, towards the right of center.

i'm not seeing it. the connection looks like it should resemble the injectors; rectangular, 2 prong connection. i'm just not seeing where to put this damn thing. under the intake? i've read it can be installed without removing the intake.
i'll be dipped

Its number 4 in the attached picture.

thank you, bubba. that was a huge help. now if only it wasn't 20 degrees and snowing..

Hi Bubba,
That jpeg of the sensor location is great. Do you have the legend that goes with it? I have been having a problem with our 960 turbo with hard starting when hot and have no gauge reading, so it might be a defective sensor (I have a spare) or in one of the wiring plugs with corrosion.

Russ

The legends seem to vary a lot depending on the year and model ... what year of 960T is it?

It is an 85 volvo 960 turbo and the engine we just put in is out of an 88 turbo. We bought it with a dead engine for $300 and picked up another engine at "pick and pull" for $225 complete. The previous owner lost the oil cap (I found it later hung up underneath) and stuck a rag in it. The cam shredded the rag and it plugged up the oil pump pick up screen. The manual I have does'nt show the sensors.


Russ

This diagram is for the 740 models, it was published in 1989. It's different than the 240 being discussed above.

Thanks Bubba, ours is a B230FT which is on that list (I checked to be sure) That will help a lot, I owe you one.:D

Russ

figured i would just add to this existing post instead of starting a new one..
has been smooth sailing all spring, now enter summer.
i was on my way into boston on saturday when i noticed my temp gauge rising quickly. pulled off the highway, popped the hood: 3/4 belts had shattered. luckily i wasn't far from home so i made it back safely. bought all 4 belts and replaced them (only $8 each, to my relief). when i fired her up for the first time all was well except i had a check engine light. pulled the codes, both the fuel and ignition systems had faults with the Coolant Temp Sensor.
Is this just a side-effect of my coolant getting WAY too hot on my trip back home? does it definitely mean my sensor is bad?
any help would be appreciated, thanks!
happy summer!

What the code means is that the ECU's have received a coolant temp reading that is outside expected parameters. It may just be coolant too hot, or the sensor is ruined. You can test the sensor for resistance, but I'd just erase the codes and drive it, then test again.
I've seen coolant temp sensors get so hot the terminals melt too, if yours has done that, start shopping for another engine.

Hi,
Will that sensor diagram work for the 940 as well, or were things changed?

It should work as long as you have the B230 motor, which a 940 should have, really all these B motors are the same as far as sensors...

didn't they move the sensors around at times over the production history?

Well, I can't speak of the whole "production history' but moving the sensors would entail a total block/head redesign. Besides the diagram Bubba provided shows all the B motors applications unchanged as far as sensors locations...

ok, then i'm not sure what i was thinking of.