Name this sensor?

A

ARBOGASTER

NAXJA Forum User

Location

Cincinnati OH

• Feb 19, 2007

• #1

I have swapped a 1998 4.0 into my 1996 4.0 cherokee. There is a plug in my harness which fits a very small plug / sensor on the drivers side of the valve cover at the very rear of the head, right on top. I do not have a plug like this on my 1998 block. I still have the plug on the 1996 block. What the heck is this thing and what do I do about it? It has only one wire and a fairly small plug in a vertical position.

thanks for your continued help

 

W

Wil Badger

NAXJA Forum User

Location

Utah

• Feb 19, 2007

• #2

O2 sensor plug would have to my guess without you posting a picture of it

 

5-90

NAXJA Forum User

Location

Hammerspace

• Feb 19, 2007

• #3

Smallish brass sensor, about a 1/2" hex? Probably a coolant temperature sensor - but I'm not sure that should be on the 1996 head.

There was a port for a coolant temperature sensor for the indicator light/gage on the #2686 and #7120 head, but that was deleted (I'd though) for the #0630 head introduced in 1996. What's the casting number for your head?

 

D

dspilot

NAXJA Forum User

Location

Hickory Flat, MS

• Feb 19, 2007

• #4

Coolant temp sensor. I have a 96, and I just changed mine about a month ago.

 

L

lawsoncl

NAXJA Forum User

Location

North Idaho

• Feb 19, 2007

• #5

That's the coolant temp sensor for the dash guage (versus the one in the thermostat housing for the computer). I think post 1996, the instrument cluster gets the temp from the engine computer via the bus.

 

M

montanaman

NAXJA Forum User

Location

Western Montana

• Feb 19, 2007

• #6

Edit: lawsoncl, you beat me by one minute

The '96 and earlier motors had 2 coolant sensors. The one on the back of the head sent information to the gauge or idiot light only. The one on the front of the head sent information to the computer to help run the motor.

The '97+ motors used only one sensor at the front of the head ... it sent info to the computer and to the gauge.

I don't know how you are going to be able to hook up your '96 dash gauge to the '98 motor.

 

A

ARBOGASTER

NAXJA Forum User

Location

Cincinnati OH

• Feb 19, 2007

• #7

I'll have to look but you think this is a temp sensor? You are describing it correctly, it's pretty small as sensors go and the plug for it is very small as well.

 

J

jeepler

NAXJA Forum User

Location

toronto

• Feb 19, 2007

• #8

is is on the block or on the intake manifold i know the one on the manifold is a manifold air temp then there is one on the valve cover and that has to do with the vacume

 

A

ARBOGASTER

NAXJA Forum User

Location

Cincinnati OH

• Feb 19, 2007

• #9

Thanks guys. Looks like I may have to put in a mechanical gauge to get a good coolant temp reading. I can plug that sensor in but there is no place to put it. At least it won't affect the drivability of the Jeep.