Mechanical Water Temp Gauge Install Write-Up

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Sep 2, 2007
Threads
304
Messages
3,104
Location
So. Cal
Okay, first of all, sorry it took me so long to get to this.

I know there were a couple of people that wanted to see the installation as I did it.

As you will see, I skip a lot of obvious steps you'd have to take in order to do this mod. Example: removing the air cleaner to get to the temp gauge.

The overall install is pretty simple. It consisted of finding a location to mount the gauge(s), figuring out how to route the water temp gauge capillary tubing(and vacuum gauge tube) through to the engine bay and finally, where you would install the temperature capillary temp probe.

This is by no means the ONLY way to do it;it's the way I chose to install it:


Parts required: You'll have to source out some of the parts yourself as I bought most of them at a local store that has since gone out of business.

-Gauge Pod (or whatever you decide to use to mount the gauge(s).

-Mechanical Water Temperature Gauge: Your choice as to brand.

-Vacuum Gauge: Your choice again.

I will post photos showing the type I used.

-Pipe dope/thread sealant.

-Various hand tools that make the whole job easier.

Here are the pictures of the Gauges, Pod and Adapter used to mount the Temp probe onto the cylinder head:

Mechanical Water Temperature Gauge:
P1120598.jpg


Vacuum Gauge: Performance Gauges & Gauge Pods GlowShift Gauges - Boost Wideband Air Fuel Gauges
P1120597.jpg


Gauge Pod:

P1120613.jpg


Temp Probe Adapter to Cylinder Head:

P1120655.jpg


I started off by picking a location to mount the Gauge Pod.
I picked the Driver's side "A" Pillar:

P1120650.jpg


Next, I found where I wanted the Water Temp Gauge and Vacuum Gauge tubing to come out through to the engine bay on the firewall:

I picked this rubber grommet because it's on the side the pod will be located on and it has a spare location for the tubes to come through:

P1120601.jpg


I then had to find a way to get the tubes from where the gauges would be mounted to the inside area of the firewall. This is what I found. This is on the drivers side part of the dash on the left hand side.

You can see the blue threaded coupling from the water temp gauge is ready to pass through to fire wall grommet.

P1120606.jpg



Make sure you get the tubing and gauges(if you're going to install two gauges) in place on the pod like you were going to mount them. If you forget to do this, you will have to pull the tubing back out to do it correctly. Trust me, I made this mistake.

Cut open a slice at the rubber grommet at the firewall so that you can get the tubes(and threaded connector) through to the firewall.

You will also have to peel back the stock sound insulation on the inside foot well area. Here you can see the light poking through the slice you made at the grommet:

P1120583.jpg


Pass the threaded connector through the rubber grommet using some needle nose pliers on the engine bay side to pull through and out:

Be careful not to damage the threads.

P1120599.jpg


Next, you will have to remove the stock temp sender and install the aftermarket temp probe(Bullet looking thing on the left hand side)

P1120615.jpg


I ended up modifying my set-up later on and still use the stock temp gauge as well as the mechanical gauge, but for purposes of this write-up, I will just show how to install only the mechanical gauge.


Here is the stock cylinder head temp sender adapter that will need to be removed to place the aftermarket adapter:

P1120616.jpg



Here is the Temp probe installed into the adapter that's installed onto the cylinder head. Make sure you use some pipe sealant. It's okay to use it here as this is a mechanical gauge.

P1120656.jpg


That takes care of the Temp Gauge. Onto the Vacuum Gauge.

Same as before. Slice an opening at the rubber grommet. and pass the clear tubing through to the engine bay. I used a drill bit inserted into the tubing to make it rigid to pass through:

P1120611.jpg


I picked this location to use the 3-way adapter to tap into a vacuum source:

P1150206.jpg


That pretty much sum's it all up.


Again, you can do this many different ways, but this is the way I chose to do it.

I found out later that there is a plastic spray that closely matches the inside of my 60 that I can paint the pod with.

Also, make sure you dress up all the tubing nicely and out of the way using zip ties to secure them.

You will need some self-tapping screws to mount the gauge pod onto the "A" pillar securely.

If you have any questions, let me know and I will try to address them when I can.

You will also have to figure out what wiring sources to tap into to light up the gauges. I was able to find some by probing into them with a meter. I wanted ones that had voltage when I turned on the ignition.

Good Luck! :wrench:
 
That's pretty cool! Thanks.

Question on a mechanical temp guage - isn't there a temperature drop between the sender and the guage? That's a long skinny tube, lots of surface area, seems like it would cool off quickly and you wouldn't get an accurate reading...

...or (more likely) I am missing something...
 
I'm not 100% sure, but I believe there is some kind of gas that pressurizes the tube. The tube never gets that hot (except where it attaches to the block) which in turn moves the temp gauge needle. I could be completely off base with this assumption, wouldn't be the first time.
Phil
 
Thanks for the write-up. I was thinking of doing pretty much the same, but am glad to see someone else give it a go first. My big hangup so far is that this will disable the stock gauge, but I guess I just have to get over it. But does anyone know of any other good spot to install the probe so the stock one can be left intact?
 
the aftermarket gauge is far more accurate than the stock one. Some people drill and tap the water neck / thermostat housing, they also make an adapter that you can put in-line on the radiator hose. If anything I would rather have the mechanical gauge in the cylinder head and move the factory temp probe somewhere else if you felt you wanted it to work too. I don't consider the factory gauge much of an asset.
 
Thanks for the write-up. I was thinking of doing pretty much the same, but am glad to see someone else give it a go first. My big hangup so far is that this will disable the stock gauge, but I guess I just have to get over it. But does anyone know of any other good spot to install the probe so the stock one can be left intact?

If you're desmogged, then you are probably not using, and can remove one of the two thermo-vacuum switches on the thermostat housing. I'm not using either of mine right now.
 
Thanks for the write-up. I was thinking of doing pretty much the same, but am glad to see someone else give it a go first. My big hangup so far is that this will disable the stock gauge, but I guess I just have to get over it. But does anyone know of any other good spot to install the probe so the stock one can be left intact?

Actually, I do.

In my write-up, I mentioned that I ended up modifying the setup.

I bought an inline adapter that fits onto the top radiator hose and mounted the aftermarket mechanical gauge there.

((((See below for picture of adapter with temp sensor attached)))

This is where I bought the adapter:

Steiger Performance

You'll have to buy a threaded adapter to fit the inline unit to accept the temp probe threaded coupler. You can find them at Autogauge.com.

This way you can run the stock gauge and the mechanical.


Good luck! :wrench:
hoseandtempadptr.webp
 
JLH911, I am also installing an aftermarket water temp gauge on my FJ-40 Why did you decide to install the sensor in the radiator house and not on the block. I am having a problem installing the probe in the block because it is too long. I need an 18 mm extension exactly like yours for the block. Where did you get the adapter for the block? I am about to order the adapter to put it in the radiator hose but I'm not sure of the diameter of the hose. Do you know if the radiator hoses on your 60 and my 78 FJ-40 are the same diameter? Sorry for all the questions.
 
Last edited:
JLH911, I am also installing an aftermarket water temp gauge on my FJ-40 Why did you decide to install the sensor in the radiator house and not on the block. I am having a problem installing the probe in the block because it is too long. I need an 18 mm extension exactly like yours for the block. Where did you get the adapter for the block? I am about to order the adapter to put it in the radiator hose but I'm not sure of the diameter of the hose. Do you know if the radiator hoses on your 60 and my 78 FJ-40 are the same diameter? Sorry for all the questions.


I installed it in the hose because I wanted to keep the stock temp gauge and the stock head does not have an extra port to add the aftermarket gauge. You could have one machined in, but I don't want to remove the head just to do that.

This hose adapter was the easiest cost-effective solution.

If you click on my name on here, you can look at the threads I started and you'll see one that asks about the hose diameter. In that thread I list the diameter.

I'm not sure if 40's and 60's are the same.

The threaded adapter I got from Jegs:

Auto Meter 2270 Auto Meter Extension Adapters & Fittings

Good luck.
 
Jose, you ended up removing this, didn't you ?? How come ?

Did it work alright in the head, replacing the stock gauge ?
 
Jose, you ended up removing this, didn't you ?? How come ?

Did it work alright in the head, replacing the stock gauge ?

I did remove it, but only temporarily. I had a coolant filter(TEFBA)in place of the temp sending unit at the top radiator hose.

Since the cooling system was pretty clean, I re-installed the temp sender as seen in my writeup in-line with the top hose. I also kept the stock temp gauge.

I have noticed that the Mechanical Temp gauge is VERY touchy and by that I mean it senses temp change right away and shows you on the gauge.

The stock gauge is pretty steady at the half-way mark once it warms up.

I figured that having the Mechanical temp sending unit at the top radiator hose was a very good location for it.
 
Jose, you ended up removing this, didn't you ?? How come ?

Did it work alright in the head, replacing the stock gauge ?


Let me guess, the recent warm weather has got you chasing what seems to be an overheating problem? I see that you've revived a couple of "overheating" threads ;)
 
Yeah, kind of -- It's on my '86 I've been chasing this for a while now ... It's not over-heating, but the the temp gauge needle will creep up, to almost the red, yet IR temp readings all-around the head and t'stat housing are no more than 180-190* F (180 t'stat) ...

Like you, I've replaced EVERYTHING - Including swapping out a couple of different gauge clusters to see if that made a difference. It did not. I'm beat. I've checked voltage and resistance across the gauges, per the FSM and all seems to be in spec.

So I'm going to install a mechanical gauge and see if I can get an accurate reading that way. I liked the hose install you did for the mechanical gauge sender but I saw you had if for sale at one point. Was just wondering why you removed it, if you did.
 
Last edited:
I just ordered all the parts for the inline sensor setup (to keep the stock gauge active). The only thing I can't find is a 1/2" to 3/8" threaded NPT adapter to use the Steiger in line unit and the sending unit. Where did you find this adapter? I couldn't find it on the autogauge site...
 
Yeah, kind of -- It's on my '86 I've been chasing this for a while now ... It's not over-heating, but the the temp gauge needle will creep up, to almost the red, yet IR temp readings all-around the head and t'stat housing are no more than 180-190* F (180 t'stat) ...

Like you, I've replaced EVERYTHING - Including swapping out a couple of different gauge clusters to see if that made a difference. It did not. I'm beat. I've checked voltage and resistance across the gauges, per the FSM and all seems to be in spec.

So I'm going to install a mechanical gauge and see if I can get an accurate reading that way. I liked the hose install you did for the mechanical gauge sender but I saw you had if for sale at one point. Was just wondering why you removed it, if you did.


What I sold was the in-line filter by Tefba. I had it on there just long enough to catch any sediment/rust. There was hardly any so I decided someone else could use it.

I still have the in-line temp sender adapter on it and it's been working good.

Have you changed out the "Fuel" gauge? I know this sounds like an error, but if you do a search on it, you'll see that it cures erratic "temp" gauge problem too.

Good luck.
 
I just ordered all the parts for the inline sensor setup (to keep the stock gauge active). The only thing I can't find is a 1/2" to 3/8" threaded NPT adapter to use the Steiger in line unit and the sending unit. Where did you find this adapter? I couldn't find it on the autogauge site...

If I recall correctly, the adapter wasn't from Autometer. I found it at some place down here called Super Autobacs but they're out of business. It came in a package along with other adapters.

Try googling and see what you find. I'll try to find out what brand it was in the meantime.



Edit: Could these work?

1/2" to 3/8" - JEGS High Performance
 
Last edited:
If I recall correctly, the adapter wasn't from Autometer. I found it at some place down here called Super Autobacs but they're out of business. It came in a package along with other adapters.

Try googling and see what you find. I'll try to find out what brand it was in the meantime.



Edit: Could these work?

1/2" to 3/8" - JEGS High Performance

That may work, but I need a 3/8" NPT threaded male end for the in line radiator piece and a 1/2" NPT threaded female end to receive the sending unit. It may work with a double ended 1/2" female piece and a double ended 3/8" male piece on either end of that adapter in the link above. However, it would be nice to find one stand alone adapter.

Unfortunately, I didn't come up with much via Google or Summit Racing.
 
Howdy JH -

I'm doing this install now and a quick Q: Did you hook the autometer gauge lighting up to the dash dimmer circuit, or just direct wire to switched 12v?

If direct wire, how is the brightness? Bother you at night?

Autometer offers a dimmer for their LED replacements - I'm deciding whether to get that or not.

Thanks!
 
autometer offers the same adapter or bushing.... I used it on my install when I had I-6. You might could do a search for the thread...I listed the part # but I don't recall subscribing to that thread. The reason for the bushing is that the hole is to shallow and the mechanical temp prope will not work without that adatper / bushing (if you are talking about installing the temp probe in teh cylinder head). Autometer also makes the adapters for a couple of differnet diameter hoses, such that you can install the temp propbe inline in teh radiator hose as the above poster did.
 
Back
Top Bottom