AutoMeter Mechanical Water Temp & Stock Gauge Question

[92GreenGT]

I recently installed a autometer ultralite mechanical water temp gauge in my car, I started it up the other day and let it run and I noticed the gauge didnt move at all. So I thought I had messed up the line during the install or there was air around the gauge or something else that was a freak of nature had happened. So I unscrewed it from its adapter and everything looked fine, so I took a lighter and held it under the probe and sure enough the gauge worked fine. Put it back in and tightened it all down, let the car run again, gauge never moved. Anyone have any ideas on why the gauge doesnt want to work with the probe in coolant but it read fine when it had heat going to it outside?

Also, when I turn the car off the voltmeter on the stock cluster only goes down to about half way on the gauge and stops. When I turn the car on the gauge pegs out, it never has done that before. The stock water temp gauge also is half way up and I dont even have it hooked up anymore? Guess I got the gauge gremlins. Thanks

 

[HISSIN50]

Intreresting issues Dave.

Do you have an adapter for the gauge (something like a 3/8 NPT male x a female that the nut above the sender can screw into)?

I cant even remember how the gauges are but if the voltmeter and temp gauge are on the same side, there could be a ground problem with the OEM gauges themselves. This would likely just be a coincidence.

I'm sure Saleen0679, JR and the other guys will have some good ideas for ya.

Good luck bud.

 

[Mustang5L5]

Where did you install the sender for the gauge??

 

[HISSIN50]

Mike, that was a question I wondered about too. Since he noted that the stock gauge is not connected anymore I figured he put the AM in the stock location.

Good to confirm that though. If the sender was in the t-stat housing, it could take forever to move.

 

[92GreenGT]

Its in the stock location on the lower intake manifold, I bought the adapter that you have to use with the mechanical gauges so it wont run out of threads so everything should be right. Weird I guess, I'll look at it some more tomorrow.

Thanks guys.

 

[jrichker]

Alternate placement for a temp gauge sender: Use the heater feed that comes off the intake manifold. Cut the rubber hose that connects the manifold water feed to the heater and splice in a tee adapter for the temp gauge sender. Be sure to use the same water feed line as the ECT sensor. That way you will get the most accurate temp readings.

Tee adapter info:
Make a pilgrimage to your local hardware or home supply center and get some copper pipe and a tee that fits the temp gauge sender. Solder two pieces of copper pipe onto a copper pipe tee with threads in the tee part. Find the correct brass fitting to match the temp sender threads to the tee fitting.

 

[Blk91stang]

I have this problem all the time. Sometimes it works fine, most of the time it will take about 15 min than finally the gauge will zoom right to 180 or whatever the coolant temp is.

I figured it was a ground problem but I've redone the connection a bunch of times and never got it to work 100% correct.

I just live it with but would love to know the fix.

 

[Mustang5L5]

That's weird. Maybe the gauige is defective??

 

[92GreenGT]

It shouldnt be a ground problem sense the gauge is mechanical meaning it has no ground wire coming off of it. Its a weird problem, I replaced my electrical water gauge(worked fine) and went to a mechanical becuase everyone told me how much better they were. Hmmm.

"If its not broke, dont fix it"

 

[Mustang5L5]

Only thing i can think of is that it's not seeing the proper coolant flow.


Put it in a pot of water and slowly boil it and watch the gauge slowly creep up. I'm thinking it might also be defective and not registering properly...only when heated fast by a lighter or strong heat source


Did you kink the capillary tubing at all during the install?

 

[92GreenGT]

Only thing i can think of is that it's not seeing the proper coolant flow.


Put it in a pot of water and slowly boil it and watch the gauge slowly creep up. I'm thinking it might also be defective and not registering properly...only when heated fast by a lighter or strong heat source


Did you kink the capillary tubing at all during the install?

No sir, I checked the tubing and it looked nice and straight. No bends in it anywhere and its a nice smooth transfer up to the a-pillar. I was thinking about doing the pot of water thing and seeing what I come up with as well. Thanks guys.

 

[HISSIN50]

Dave, your posts sound top notch to me - you're thinking of the same stuff that most of us would too.
I'd see if AM will swap it out for you (their Customer service is generally outstanding). I have read of a handful of folks having had mech gauge issues over the years, and you might be in that same category. The problem to me is that this gauge cannot really be deemed reliable now - in the back of your mind you will wonder about it.

JMHO.
Good luck bud.

 

[92GreenGT]

I tried the heat water up on stove and take water out to car thing today, the gauge worked perfect. I got the water up to boiling temp and walked out with the pot and unscrewed the prob from the adapter and put it in the pot, held it for a few seconds and then walked over to the car and it was already showing 180 and I could see the temp fall as it was cooling off.

This has to be a coolant flow problem, maybe my thermostat is beginning to stick? For a side note, I dont drive the car right now, these are just times I have the car idling in the driveway. I dont let the car run for long periods of time, but I did let it run for 10 minutes and the gauge never moved. Maybe im just not letting it run long enough? Surely the coolant temp would go over 120* in 10 minutes worth of idling on a 85 degree day?

 

[Mustang5L5]

Can you take a picture of how the probe is mounted on the car??

 

[92GreenGT]

Sure thing, I'll go try to take one right now. May not turn out good having to use flash, if not..I'll hook you up tomorrow morning.

 

[92GreenGT]

Look over the dirt, car has been sitting for all winter+spring with no cleaning.


Shot with Canon PowerShot A620 at 2007-07-06

 

[Mustang5L5]

Hmm, ok it looks exactly like my setup. Same number of threads showing and everything. I had read that sometimes the adapters put the sender to high up that it does not see proper coolant flow.

The gauge should work then.

What is odd is that you say you get no movement of the gauge at all. When i put my mechanical gauge in, i didnt have that adapter so i was forced to wait a week while i ordered one from summit. During this time, i just layed the sender on the lower intake zip tied to the injector harness. The gauge would still work, it would read up to 130 degrees or so. That was just heat from the engine, but it worked like that.

If coolant flow was the problem, the gauge should still register the ambient heat of the engine.

What is the minimum temp on the gauge? I know there were a few. Perhaps your thermostat is stuck open keeping the coolant at a temp lower than the gauge can read?? As you can see, i'm trying to explore other possibilities

 

[92GreenGT]

I think the lowest number on the gauge is 120*? I think it reads from 120-240 or something around there, its a full sweep gauge.

 

[92GreenGT]

Figured I would update the thread, ever since I pulled the probe and put it in the hot water to test the gauge, the gauge has worked perfect. Rises with the temp nice and steady and doesnt move around or anything, glad I went with the mechanical and got rid of my electrical finally.

Also, like I figured the stock voltmeter and coolant gauge problem was just the needles had got stuck out, I done the foglight mod on the car the other day and since I was that far in, pulled the cover off the instruments and cleaned it and pushed the needles and they fell right down to stock location and they too are working correctly now. Glad to have both of those little things figured out, also..here is a pic of the car with the foglight mod(finishing the garage, look over the mess and the hood isnt fully shut, dont want to share Mobs "hood gap" pride)


Shot at 2007-07-16

Thanks for the help guys.

 

[HISSIN50]

Nice work.

It looks sharp Dave.