Originally Posted by VTEK1
Unfortunately, I can't say i'm a newbie, but I'm kind of stumped. I just replaced my temperature sensor on the water pump last week. Since I did my Jeep sits right on 210 and the e-fan has been running a lot more than ever. My old sensor read just above 180 all the time and if it got to 210 the e fan would kick on.
Now, MA and the rest of NE have been experiencing a crazy heat wave lately so I'm sure this is more of a coincidence then anything however.....
I'm worried about the e-fan running all the time and does this mean that my old sensor was actually allowing my Jeep to run too hot!?
I replaced it because every once in a while it wouldn't send a message to the dash and would suddenly work if I gave it full throttle..... <---- is this a clog issue.
I'm thinking I'm going to just replace almost everything r/t to cooling because my XJ now has 178000 miles on it.
Critical question - year & engine?
There's no temperature sensor on the water pump proper, but there could be one, two, or three sensors - depending on year & engine. And, the various sensors would have different functions.
1987-1990 w/6-242 will have THREE sensors:
- Driver's side rear of the cylinder head. Drives the IP gage or lamp.
- Driver's side radiator tank. Drives the relay for the electric cooling fan.
- Driver's side of cylinder block, behind the exhaust. Generates the signal for the ECM.
1991-1995 w/6-242 has TWO sensors:
- Driver's side rear of cylinder head, as above.
- Thermostat housing. Drives the electric fan and generates the signal for the ECM.
1997-up w/6-242 has ONE sensor:
- Thermostat housing, drives ALL functions (feeds signal to ECM, ECM drives IP indicator and electric fan over OBD-II CAN Bus.)
I'd have to look up data for the 4-150 engine, as I don't deal with that engine much. And 1985-1987 w/Renault turbodiesel is another critter entirely, as are the 1984-1986 w/Chevvy V6-173...
Design operating temperature for the 4-150 and 6-242 run 205-210*F, although earlier years may be "pulled down" with some simple modifications - with no ill effect (OBD-I is somewhat picky about operating temperature, and may
throw a code if it stays low. OBD-II damned sure will
throw a code on you!)
You can see that this is not as simple as the question you post - more information, please!