Manual temp guage location

[drifto77]

Given a choice, I'll put it in the block - if anyone pulls that drain plug, please tell me the thread size. I've not gotten around to pulling one out yet - just haven't had a real need to dork around with the thing (even though I have made a couple 8m/m square drive keys.)
5-90

Guess I need to look for that plug agian, I would rather put it there than in the hose.

I don't look for trouble - it finds me with alarming regularity...

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............... you too, eh?

 

[csr_011]

Ok, Question...

If i put the manual guage probe/thingy in the sensor location at the rear of the head, will the idiot light stay on all the time since its sensor is not in the head/block anymore?

If so/not, what do you do with the old sensor and wiring?

Cory

 

[drifto77]

Dont know what year ya got, but the hole is too small on a ' 91.

BTW ....
is this the link you wanted?

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1061&prmenbr=361

 

[csr_011]

87 4.0....

Cory

 

[corbinafly]

Given a choice, I'll put it in the block - if anyone pulls that drain plug, please tell me the thread size. I've not gotten around to pulling one out yet - just haven't had a real need to dork around with the thing (even though I have made a couple 8m/m square drive keys.)5-90

I'm 99.9% sure that it's 3/8" NPT. I pulled it once on my stroker to drain the coolant because I had to change one of the core plugs. I also took a look at my spare 4.0 and compared what I saw with a 3/8" NPT to 1/8" NPT bushing that I had and it looks like it. I would have actually pulled the plug on the 4.0 to check for size and also for clearance behind the hole, but I don't have the correct square drive key. The plug on my stoker takes a hex head.

Ok, Question...

If i put the manual guage probe/thingy in the sensor location at the rear of the head, will the idiot light stay on all the time since its sensor is not in the head/block anymore?

If so/not, what do you do with the old sensor and wiring?

Cory

I believe the light would stay on all the time, but I think all you would have to do would be to ground the connector.

K

 

[5-90]

I would have actually pulled the plug on the 4.0 to check for size and also for clearance behind the hole, but I don't have the correct square drive key. The plug on my stoker takes a hex head.
K

And you won't, unless you flag down a tool truck or do what I mentioned earlier - get an 8m/m cheapo hex key and attack it with a die grinder or a bench wheel. I had to make drain plug keys for my Peugeot gearbox that way... Takes about two minutes - you just grind two opposing corners down so that the key will fit into an 8m/m square hole, and yer good to go!

I tried 1/4" and 3/8" square with no luck, so I'm pretty sure it's 8m/m. When I get that damn plug out, I'm putting a valve in! Gotta be an easier way - and having a valve will allow me to attach a hose to control draining...

5-90

 

[JEONLYEP]

Mine's a 91. Tomorrow I'll know what size the hole is in the back driver's side of the head. The first temp gauge I got (Sunpro) was too big, but they make one with a smaller temp probe. I'll let you know what I find out after the smaller probe gets here.

 

[drifto77]

Mine's a 91. Tomorrow I'll know what size the hole is in the back driver's side of the head. The first temp gauge I got (Sunpro) was too big, but they make one with a smaller temp probe. I'll let you know what I find out after the smaller probe gets here.

I have not bought me a guage yet ...... if you get one that fits that hole let me know what you got PLEASE ! ! ! (what gauge and a part number and all)
BTW ..... i like the way you set up your "only in a jeep" handle.

...........................................................................................................
Hey 5-90 .......
Is this plug the one under the 2nd freezeplug from the back of the motor?
if so .....what a PITA to get to ! ! (kinda)

..........................................................................................................
corbinafly...
i think mine is a hex also or i just screwed up a good hex key.

 

[corbinafly]

Mine's a 91. Tomorrow I'll know what size the hole is in the back driver's side of the head. The first temp gauge I got (Sunpro) was too big, but they make one with a smaller temp probe. I'll let you know what I find out after the smaller probe gets here.

I believe it's 1/8" NPT.

K

 

[corbinafly]

Hey 5-90 .......
Is this plug the one under the 2nd freezeplug from the back of the motor?
if so .....what a PITA to get to ! ! (kinda)

Yup. That's the plug. I have a Borla header and it's pretty tight down there. I'm sure it gets REALLY hot down in that area when idling or at crawl speeds. Just wondering if the intense heat would mess up any wiring or connections coming from the sender if if was placed down there.

K

 

[JEONLYEP]

will the idiot light stay on all the time since its sensor is not in the head/block anymore?

If so/not, what do you do with the old sensor and wiring?

Cory

Most likely it'll stay one...... Pull the bulb....

BTW ..... i like the way you set up your "only in a jeep" handle.

Thanks. Some get it, some don't.

 

[5-90]

The four I've got (1987-1989) are all 8m/m square, from what I've seen so far. I haven't gotten around to pulling any yet, but the one on my 87 is exposed well, so maybe I'll get around to it sometime.

The hole at the back of the cylinder heads I've got are all threaded either 1/8"NPT or 1/4"NPT - and I'm more inclined to think 1/8"NPT for the moment.

That plug is behind the exhaust collector, and is a pain to get to. I'm going to look into a way to install a right-angle valve, and see if I can't operate it with a remote cable somewhere so I don't have to crawl under there to drain the block. It's a matter of finding an easier way...

If you get a plug out, let me know - and I'll compare it to mine when I get a chance to make sure...

5-90

 

[JEONLYEP]

My 91 4.0 is 1/8 NPT.

And the only gauges that match that are electrical. All the mechanical gauges that I looked at were 1/4 or bigger.

Any way I bought a new sending unit for my factory gauge, we'll see how that goes.

 

[JEONLYEP]

I ended up getting a new mech gauge. For where to place the sender, I got a 1/2 inch brass tee and a couple 1/2x2 brass nipples to put the send inline on the heater line headed to the heater control valve. I thought about the plug down between #2, #3 cylinders
Two reasons for not doing the drain plug.
1. Location. Too hard to get to, and not sure of the room for the lead going away from the sender.
2. Location. That plug is located pretty close to the inlet of the block (from water pump) and so low that I was wondering if the reading taken from there would be accurate? The water hasn't been thru the head at that location.

Not finished yet, but I'll let you know.

 

[hotrod22]

How about some pics when you're done, I am dealing with the same dillema.

 

[5-90]

Put some heat-protective sleeving on the wires (go to a performance house and do a lookup for "Firesleeve" or something similar) and you should be fine - the knock sensor and ECU/CTS are both down there, and that header gets damn hot...

I hadn't though about putting a sensor in that hole - mainly because I'm thinking about putting a valve down there to make it easier to drain the block. Probably set it up to be cable-operated, so I don't have to stick my paws down there...

5-90

Yup. That's the plug. I have a Borla header and it's pretty tight down there. I'm sure it gets REALLY hot down in that area when idling or at crawl speeds. Just wondering if the intense heat would mess up any wiring or connections coming from the sender if if was placed down there.

K

 

[drifto77]

I broke down and ordered an electric gauge from Summit. Hope the sender is the same size as the stock one.
(havent got it yet)

P.N. EQU-6042

 

[JEONLYEP]

I used a 1/2 inch brass tee, with 1/2 inch male by 5/8 inch hose barb adapters. The 5/8 is almost too small for the heater hose, I think it's 3/4, but I clamped it down and it's holding for now.

First I had it installed with the line going straight thru. And the temp bulb coming out the side. But the temp bulb bottomed out on the back side of the tee. I then changed the flow thru the tee to be 90 degrees and the temp bulb coming out one end of the tee.

To make this work I placed the tee to take the place of a bend in the heater hose close to the heater control vavle.

It seems to work, now all I have to do is get it in the dash.

I'm going to put it in place of the stock gauge, like I did with the oil pressure gauge. A 1 1/2 inch gauge goes in pretty well, but not perfect.

 

[drifto77]

Looks good, guess if the sensor that comes with mine dont fit thats what I will do.

 

[JEONLYEP]

Looks good, guess if the sensor that comes with mine dont fit thats what I will do.

From what I found while trying to get this done, "most" electric pickups are 1/8 inch. That's the same size as the hole in the back of the head for the stock sender. I would have done an electric one if I'd have found one that was 1 1/2 inch.