Hey guys. Looking for advice on how to install a temperature gauge on a 98 Jeep Cherokee 6-cyl 4.0L

A little history- recently started a cooling system overhaul of the Jeep after it was overheating and spewing terrible rusty orange coolant after some regular street driving. Tires Plus did the blue-to-yellow liquid test and found a BHG and said I practically needed a whole new cooling system (quoted me $1600!!!). We have none of the typical signs of a blown head gasket so we decided to just focus on the cooling system. Flushed it real good with a t-flush kit, pulled the radiator and overflow resv. to flush it, flushed the heater core (badly clogged!), new rad cap, new water pump. Skipped on a new t-stat because it appeared to be functioning. If I keep getting overheating problems I may further look at the head gasket...or maybe do a 3-core radiator, rig the elec fan on a switch, new t-stat and high flow housing...

Me and my pops did the work over the past two days. I have to leave back to school soon on a 130 mile drive and having a temperature gauge instead of just the idiot light would ease my nerves. Since working on the colling system, I have driven it on 3 trips, both highway and street, none longer than 30 minutes. No overheating yet, but the t-stat housing is reading 226* on a temp gun, so I think its still getting a little hot.


So the temp gauge-- I only have an idiot light and want a gauge. Ive been reading through a lot of threads and cant find a lot specific for a 1998. I guess in 96 when cars switched to OBDII Jeep went from 2 temp units to 1. They removed the 1-purple wire sending unit from the back of the head leaving only a casting knot... and now there is only the sensor on the t-stat housing.

In there any way to install a temp gauge besides putting an adapter into the t-stat??? Ive seen people put a "t" into the housing so they can have their sensor for the ECU and then their new one for their gauge. Is this what most people do, or is there another method (besides buying a ScanGauge)??? Ive heard this "t" or "y" adapter method has problems because with the adapter the sensor is no longer in the water jacket. Also, if I do this method does this gauge have to me electrical or mechanical (or can it be either)?...id prefer electrical.

Hope yall can help. There appears to be many knowledgeable folks on here. Youve helped me a lot so far.

 

Here's the easy way, just plug it in the ALDL port under the dash and way more info than just coolant temp. U need to change the t-stat, u'll sleep better at night. Ooops, that's what I get for not reading the entire post.

http://www.scangauge.com/

One of these mounted in the top radiator hose would allow u 2 install the small sending unit that an electrical gauge uses.

http://www.jegs.com/p/Flex-a-lite/Fl...17700/10002/-1

...or 1 of these, remove the drain plug and screw in the gauge sending unit.

http://www.jegs.com/p/JEGS-Performan...06363/10002/-1

1 other possible option, install the gauge sending unit in the 3/4" rubber heater hose using some brass fittings from a hardware store.

 

I told my pops we should do the thermostat! Its cheap and we had a bunch of stuff already off the car. Feeling the hoses and watching the temperature after starting up, he was convinced it was opening and closing fine...But ive read that they can open partially. I think when I get back to Gainesville Ill spend the $13 or so dollars and get a Mr. Gasket high flow t-stat. Debating on a 180, or the 195 as it came stock. Ive read viewpoints from both sides. Ive had overheating problems, leading me to want a 180, but some say the 180 is just a bandaid for overheating problems and the 195 should be used as the Jeep was designed for it, and it will get better mileage.

Thanks for the options on a temp gauge solutions. I had heard mention of doing it through the heater hose. Looks like I might try one of these out. That, or Dad said he was looking for a ScanGauge so he might pay for it!

 

A properly functioning t-stat does 1 thing & 1 thing only.....control minimum coolant temp. This time of year it should be running cool...at or just above the t-stat temp.

 

Just make sure the sensor is in a flowing stream of coolant. I have seen a few sensor install pics on this site that are strongly incorrect. Putting a tee fitting into a hole with the stock sensor on one leg and aftermarket sensor on the other leg will not work correctly. When a liquid temp sensor is at the “dead end” of a channel, it will at worst have nothing to read except an air pocket, and at best it will be reading a stagnant eddy stream of coolant.

Best place to put a sensor is in the thermostat housing, or at least in a coolant temp sensor adapter that splices into the upper radiator hose. (Ugly but works.) Either way, make sure to probe the sensor deeply into the coolant flow.

 

..........or in the 3/4" heater hose as '98 models have continuous flow as soon as the motor starts.

 

On the OBD I and OBD II years, doesn't the antifreeze flow continuously through those hoses until you turn on the heat which actives the vacuum valve allowing it flow through your heater core inside the dash?

 

I've got to do a similar thing with my XJ. I've heard and seen the y or t type and understand that there is some possibility of not being as accurate and a possible air pocket. This why I'd like to find out if you can place it in the hoses that feed the heater. If it cycles between the two hoses before the heater is activated, this would be a good solution to this type of problem.

 

Keep the sensor as close to the t-stat housing as possible.