loligator

Hi all,

I recently purchased a 96 Cherokee Country that has some (hopefully just) minor issues. One of them is a temp gauge that doesn't pick up a reading. Easy fix right? The temp sending unit on the rear of the block controls the gauge while the one in the front is for the ECU/electric fan.

After getting her home and getting ready to replace the sensor I'm surprised to find it dangling from the connector tucked away in some wires up against the firewall. I look for the hole where it's normally screwed in and there's no hole.

After doing LOTS of research it seems like one of the previous owners must have replaced the head with a 0630 from somewhere between 97 to 99 since 96s are the only ones to use this head and not have the two temp sensors combined into one screwed into the thermostat housing.

I came across this after market thermostat housing that seems to have been made to solve my exact problem: http://www.hesco.us/shop.asp?action=...2#.UlKa32RATDa Has anyone used this before? How'd it go? There also seems to be the home brew solution of using various brass plumbing fixtures but I'd rather do it right.

I'll need to run some wire so I can actually hook it up but I'm not sure what kind of wire I should use. Any suggestions would be helpful. A link to something on Amazon would be even more helpful Also, how should I splice it all together? Something tells me simply wrapping it up in electrical tape isn't going to hold.

I'm also concerned about the head replacement. I've read often if the head cracked (which I'm assuming is the case; why else would it be replaced?) coolant can leak into the motor and ruin it. I took this thing on a good test drive before purchasing and also drove it home (about a 10 mile drive) and she seemed to respond well when accelerating and sounds good when idling. The oil looks good and there's no white gunk on the oil fill cap or dip stick (although the previous owner could have easily cleaned it off if he knew of the problem). He never mentioned anything about the head being replaced but did say when he bought it about 5 years ago he replaced the radiator and thermostat because of an overheating issue.

Sorry for the novel; I guess I'm worried what I thought to be a good deal might end up being me purchasing someone elses problem.

cruiser54

Thread the sender into the later model housing. Extend the wire using 16 gauge wire.

loligator

okay great I'll give that a try. think I should be concerned with the head being replaced? I guess there's no easy way to check that the gasket was done right.

cruiser54

Wire the sender. Drive it.

loligator

hey crusier (or anyone else out there),

I tapped the therm housing, installed the gauge sensor, and ran the wiring. I'm now getting a reading but the highest temp reported is 150/160 degrees. That seems way too low. My other Cherokee is at about 200/210 during normal operation.

Any ideas on what could be the issue? Of course the sensor comes to mind but I thought I'd ask before I get a new one. I used 16 gauge solid wire. What's there is braided. Would that matter?

cruiser54

Not sure on the wire. I always use braided in auto applications.

New sender?

freegdr

No thermostat ?

loligator

I put a new thermostat in. I used a 180 since they didn't have 195 in stock. I'll see if I can't find a new sensor and go from their. I read on another forum they aren't easy to come across but we shall see.

Just in case this bit of info helps, I timed how long it took my other Cherokee to get to the 1/4 mark (about 155 degrees) on the temp gauge. It took about 5 minutes. The project one takes about 5 minutes as well.

cruiser54

With a factory stat, at 40*F outside, my 2 Jeeps take about 3 minutes for the needle to get to the center of the gauge.

RTorrez1

Before you buy a new sending unit you should verify the temp with a I.R. temp gun aimed at the T-stat housing.

loligator

just to update, I ordered an IR temp gun but it's taking forever to come in (possibly as late as Nov 5th). Because I'm impatient, I bought a new sensor and finished flushing the coolant system. I also redid the wiring with new 16 gauge braided low voltage wire. Still no difference. Out of the probably 10 times I've had her running waiting for her to reach temp, only once did the gauge get to 200. Every other time it gets to only 160ish.

We'll see what the temp gun has to say.

loligator

the gun came a little early and i gave it a try. to ensure i was using it correctly, i tried it on my 95 cherokee first. got a 200* reading when them temp gauge said it was 200* as expected. i then tried it on the 96 and the therm housing gave me a reading of 170 degrees. the gauge was a little under the first line, i'm guessing at about 150*. i put the heat gun on the sensor itself and that read about 145*. this makes me think the 150* reading on the gauge is correct. i'll have to take a pic for clarities sake. the two spots where i took the readings are about a quarter to a half of an inch apart. i can't imagine that much of a difference. i also took the temp of the upper and lower hoses that go into the tstat housing on both cherokees and those read the same. i have a 180* tstat so the 170 reading should be correct, right? fwiw, the gun i bought isn't the greatest and the reviews said it tends to be 10 to 20 degrees off. seems like mine can be about 10 degrees + or - based on tests i did with our oven.

loligator

here's the pics (not sure why they uploaded upside down or sideways they weren't like that on the computer):

the temp gauge after 20 minutes of running idle


temp of the housing. the red dot shows where i was hitting on the housing


temp of the sensor itself. it's hard to see the red dot in this pic but i'm basically on it as close to the housing as possible.


another pic of the sensor temp from a different angle


a pic of the sensor itself. the top sensor is the computer/fan sensor that's normally there. below is the one for the gauge