Temp Sending Unit Adapter???

[csx4590]

I can't get a photo to post but I bought a new temp sending unit and it appears that it is too small to fit in the hole that it's supposed to go into. The brass plug that it would thread into appears to be too big. Can anybody post a photo of what the factory set up looks like???

Thanks...

[mopar0166]

I don't have a stock setup but I do know what your talking about, if you want I can take a pic tonght

[csx4590]

This is what I have now. It's a temporary aftermarket gauge that I want to replace with the factory setup even if it isn't accurate...

[John_Kunkel]

In most cases a simple reducer bushing will take care of the size difference but bushings are usually so deep that they shroud the temp sensing bulb of the sender. The correct reducer is a face bushing.

[rebby]

Factory sender will fit in the spot indicated in picture. I actually plugged that top port and used this spot for my temp sender instead. I'm not 100% sure which one is factory correct but this did the trick for me.

[birdsandbees]

The port shown in your picture with arrow is the correct port for OEM sender.

[csx4590]

I can't find anything that looks like that on my housing. And with the alternator and A/C bracket in the way, I don't think it would fit. I don't see the smaller hole that you guys are pointing out. The housing number best I can see is 2780987 and then it looks like a 1...

[birdsandbees]

It is accessed through the 1.25" or so hole in the alternator bracket.

I just happed to have been media blasting mine today..

[VegasCharger]

I have a couple of the stock heater temp sending units if you need them.

[csx4590]

It is accessed through the 1.25" or so hole in the alternator bracket.

I just happed to have been media blasting mine today..

Here is a close up of that area on my car. It looks like it has a bolt in it instead of a plug. It's in the open area to the left of the heater hose clamp screw. Is that bolt one of the ones that hold the water pump housing to the block or is it just a bolt plugging that hole? If it is just a bolt, I can take it out and put in the sending unit correct? Does having the sending unit there instead of at the top affect the output of the sending unit? I know it's a lot of questions. trying to get this done before this weekend as the weather looks great...

Many thanks...

[birdsandbees]

That is the correct spot for the sender. There are 3 bolts hold the pump housing on (each side), as you can see in my media blasting shot, and that "bolt" you refer to is just the sender hole. Hopefully though, it's actually a plug (and not a bolt) as that hole should be 1/8NPT pipe thread.

[rebby]

Hopefully though, it's actually a plug (and not a bolt) as that hole should be 1/8NPT pipe thread.

My thoughts exactly. If this has been drilled/tapped to use a bolt as a plug, you'll need to get a reducer and use the port at the top (or do some real work to restore the original 1/8NPT thread). Good luck!!!

[birdsandbees]

I have a couple of the stock heater temp sending units if you need them.

I could use one of those VC.. PM me a price with postage to L9M2C1 in Ontario. Thanks.

[csx4590]

That is the correct spot for the sender. There are 3 bolts hold the pump housing on (each side), as you can see in my media blasting shot, and that "bolt" you refer to is just the sender hole. Hopefully though, it's actually a plug (and not a bolt) as that hole should be 1/8NPT pipe thread.

It was a bolt but it wasn't in very far. The sending unit went in and tightened up nice. I think I have it fixed. Just have to top off the anti freeze and take it for a quick ride. Does having the unit there instead of on top affect the reading and if so by how much? My buddy has one of those digital temp guns so I can check it. All I need now is a plug for the now unused top hole which is temporarily plugged by the old aftermarket set up. I think I saw those available somewhere...

I'll let you know how the test goes later today. I pulled a midnight shift last night so i need a nap...

Thanks...

[rebby]

Before you fill it up, did you put any sealant on the sending unit before installing? I've seen a lot of these get installed w/out anything and they end up developing a slow leak.

I doubt that you'll see a change in temperatures between the 2 locations, at most, I'd expect a few degrees of difference which should be irrelevant as far as the gauge is concerned.

[csx4590]

It had some of that teflon/plumbers tape or whatever it is already on it. I'll keep an eye on it...

[rebby]

It had some of that teflon/plumbers tape or whatever it is already on it. I'll keep an eye on it...

You should be good to go then.

[igozumn]

Does having the unit there instead of on top affect the reading and if so by how much?

Yes and no.  Depends on what the adapter looked like that was used in the top of the housing.  When I put the Fitech on my Charger and put a new aluminum housing on, I was concerned about the Fitech supplied adapter for the GM sensor leaking, because it appeared to almost bottom out before getting tight enough.  I bought a new brass fitting at the hardware store that didn't go so far into the housing.  But, it looked like the sensor wouldn't even get wet from coolant due to it not screwing into the adapter, and then the housing far enough.  Used the Fitech supplied fitting, the Fitech supplied sensor and tightened it up and everything sealed ok and the sensor is in the coolant flow.  

The original sensor in the front hole is where it should be.  So, whether or not you see a difference, again, yes or no.  Depends on if where you had it was in the flow or not.  Probably was and will read the same.

[csx4590]

The mechanic at the last shop it was in was not a Mopar guy and a bit of a hack. Back in 1993 when I first bought it, it had a 383 in it and the gauge worked fine. I had the whole cluster redone and recalibrated  by Performance Graphics. I had to move the car from one shop to another as the first shop was run by a total a$$hole. We decided to put a 440 in it this time around. The hack said the gauge didn't read right. So he rigged up the aftermarket gauge. I just want to see what the factory gauge does now that I have it hooked up right. Even if it's wrong (unless it's way off), I can't stand looking at dead gauge...

Thanks again for the help. This place is great...

[csx4590]

Does having the unit there instead of on top affect the reading and if so by how much?

Yes and no.  Depends on what the adapter looked like that was used in the top of the housing.  When I put the Fitech on my Charger and put a new aluminum housing on, I was concerned about the Fitech supplied adapter for the GM sensor leaking, because it appeared to almost bottom out before getting tight enough.  I bought a new brass fitting at the hardware store that didn't go so far into the housing.  But, it looked like the sensor wouldn't even get wet from coolant due to it not screwing into the adapter, and then the housing far enough.  Used the Fitech supplied fitting, the Fitech supplied sensor and tightened it up and everything sealed ok and the sensor is in the coolant flow.  

The original sensor in the front hole is where it should be.  So, whether or not you see a difference, again, yes or no.  Depends on if where you had it was in the flow or not.  Probably was and will read the same.

I have a photo above that shows the way the last guy hooked up the aftermarket gauge. I will eventually take that out and just put the correct plug in it...

[igozumn]

Most of the aftermarket gauge probes are long enough to not have the sue I was dealing with on the Fitech. The stock GM sensor has a little bit shorter tip on the end. I was thinking of buying an aftermarket temp gauge, as I know my factory gauge is off. But I decided to put that towards the efi, and I can read the temp off it and see just how far off the original is.

[csx4590]

Took a test drive this morning and the gauge seems to work fine. It might read a little high but I can deal with that. The aftermarket gauge was reading 190 when it was warm. The factory gauge reads 190 or a little above. Motor is still relatively fresh so that may change in the future but for now, I am a happy camper. Just happy to have a reading at all. Thanks again for the help...