Mechanical temperature gauge installed

[pinballlarry1]

Sent: 8/6/2007

I installed an Equus mechanical temperature gauge today, pretty easy and only $17 at the local Kragen auto parts.

Equus model 6242, 2" dial, fit into the aluminum plate I made for the radio in the center of the dash. I like the long dial sweep and nice illumination.

I ran the sender through the rubber grommet that also seals the windshield washer tubing, it was in a nice center location above the radiator. I removed the existing 3/8" pipe threaded plug in this location on the passenger side water outlet.  New brass fittings for 1/2" and 3/8" pipe are included. Hot water hose to heater is on the right, 2 electrical temp senders on the left. Very happy to see the gauge stay between 180-195 so far. Still going to do some test driving in the mountains next week.

pinballlarry

[Oz]

Sent: 8/9/2007

Gotta love those nice, inexpensive upgrades  Good job, bro!  - Sob

[Winnebago Warrior 94]

I'm not sure my temperature  gauge is working .what should the temperature  of  the  engine run ..it's just staying on 100 degrees . .not sure what and average running temperature  is ..thanks

[LJ-TJ]

Fuel Pressure   6 to 7-1/2                                                  Pg 14-56 Dodge Motor Home Chassis Service Manual

Oil Pressure at Idle  8 PSI.  at  2,000 RPM 30-80 PSI.  Pg 9-59 Dodge Motor Home Chassis Service Manual

Trans  Temp   150 to 200 degrees F  (175) Pg 21-16 Dodge Motor Home Chassis Service Manual

Oil Temp

Water Temp 177 Deg (or 8 degs below Thermo Opening Temp) Pg 7-4 Dodge Motor Home Chassis Service Manual

[Winnebago Warrior 94]

Ok the temperature   gauge next to the oil gauge inside  the truck ..what temperature  should that be reading ? I'm a woman and don't know alot of mechanical  terminology . .lol sorry about that ..is that showing engine temp ? Water temp or oil ?mine is reading 100 degrees   but it starts out at that on gauges ..how can I tell if it's working or not .,d hold I drain radiator and run engine to see if gauge  moves..lol ..just a joke ..how do I know .don't want my engine overheating

[tmsnyder]

It should show the engine is cold when you start it up, then after a few minutes you should see the needle move up to the normal operating range.  A typical thermostat is 195F so you would see this temperature after driving around a little bit.   When climbing a hill, you may see the needle climb toward the red zone on the gauge which is ok.


In a nut shell, if you aren't seeing the needle move at all, it's not working.

[Rickf1985]

And oil pressure on a Chevy should be around 20-30 lbs at idle. TJ is quoting old Dodge specs, they were a little strange. W%

[Rickf1985]

Ok the temperature   gauge next to the oil gauge I side the truck ..what temperature  should that be reading ? I'm a woman and don't know alot of mechanical  terminology . .lol sorry about that ..is that showing engine temp ? Water temp or oil ?mine is reading 100 degrees   but it starts out at that on gauges ..how can I tell if it's working or not .,d hold I drain radiator and run engine to see if gauge  moves..lol ..just a joke ..how do I know .don't want my engine overheating

I would venture to say the gauge is not working. Are all the other gauges working? Chevrolet has a dashboard which causes problems at the ribbon connector sometimes, or it could be the sending unit, or someone may have taken the thermostat out of the engine. If you have a laser temperature gun you can aim it ate the thermostat housing where the top radiator hose meets the engine and that will give you the engine temperature. (which by the way is the water temp). Those laser guns are pretty cheap and handy for a lot of uses. This will narrow it down to whether it is the engine or something else.

[Winnebago Warrior 94]

I will have to check that out and see if I see a thermostat on the radiator ..I think all the other gauges are working ..the battery gauge is working ..gas gauge ..oil seems to be working  but 5 the thermostat hasn't moved  ..but the furthest I have driven it is 10 miles on the back roads ..it going over 30 miles -40 ..we are getting it road ready and we have to get it inspected ..how far would you think we need to drive ..what does the thermostat  look so I can tell if it is on there or not .we haven't done a  radiator flush yet but we plan on doing one soon ..thanks for yalls help

[tmsnyder]

Idle it in the driveway for 5 minutes, it should get up to temperature in that short of a time span.  The needle should go from off the gauge low, to the middle of the range once it warms up.  I don't know if you have numbers or anything on your gauge but the temperature would be cold, outdoor air temperature, to 190F within 5 minutes of idling if everything is working right.

If it starts to warm up but never gets up to operating temperature and runs cold, then you would suspect the thermostat is stuck open and should be replaced.  The thermostat isn't on the radiator though, it's under the radiator hose gooseneck on the top of the front of the engine.  You would have to take that off the engine to check it, and if you do that you might as well put in a new one. 


Right now though it sounds like your temperature gauge is not working, thermostat might be fine. 


Not the end of the world, as long as you're not leaking coolant and you keep it topped off it's ok to run it like that for a little while, while you figure out how to fix the temperature gauge. 

Engine temperature is probably the most important one to know b/c you can pretty quickly ruin an engine by overheating it.   Without a gauge, you won't know if you're overheating.

My stock gauge died too so I put in an Autometer Z-series gauge, it was ~$40 from Summit.  I'm putting in a tranny temp gauge alongside it as well.

[CapnDirk]

This should only be done for a short time as a pressurized radiator is that way to keep from boiling.


Take the radiator cap off and make sure there is coolant to the top.  Put a meat thermometer down into the coolant and start the engine (good idea to have a drain pan under there to catch and coolant that might burp out).  As the water heats up, the meat thermometer will rise, if the gauge does not, I bet money on the sending unit or gauge.  Sending unit probably easier to deal with if you want to invest the money in a gamble.


If thermostat is working correctly your upper radiator hose (with cap back on) will be hotter than the lower one.  If after the engine is running for a while both are about the same, it's likely the thermostat being open.

[Rickf1985]

And the thermostat is on the engine at that end of the hose, not on the radiator end, It would not be that easy. If the thermostat is working correctly then the upper radiator hose will not get hot until the thermostat opens. That could take five to ten minutes at idle. Once the thermostat opens the top of the radiator will get hot pretty quickly,  or the side if it is a side tank. If the hose starts to get more than a little warm within the first minute or two then either the thermostat is stuck open or has been removed. That means the engine is running too cool and that is also not good for an engine since you will not evaporate the normal moisture that gathers in the oil from condensation.

[Winnebago Warrior 94]

Thanks for the help ..I will try and get out here today and check it ..I have a  metal temperature gauge that I will take the cap off the radiator  and stick it in and get the temperature  readings and report back to you ..if I don't  run out of time to do that today. . ..we are planning  on doing a radiator  flush pretty quick ..so far there hasn't been any radiator  leaks or anything  like that..so that's on the plus side .the temperature  on the gauge inside the truck is just staying at 100 degrees . .but that is what it starts out at ..all the other gauges  are working  good .the gas gauge even seems to be working ..is haven't filled the tank up all the way yet ..we did change fuel filter ..hubby said it was yucky..is plan on putting non ethanol  gas  in the tank when i do fill it up  .when we change out the radiator  fluid do yall have any helpful tips for that ..is there any certain  does or don't s before we get started ..is like helpful tips from the pros 😃

[tmsnyder]

There is a lot of info regarding troubleshooting the temperature gauge.  Here's one guide from American Autowire, the sensor in question may be in the center of the driver's side cylinder head.  It's #2 on the diagram here: http://www.classicwinnebagos.com/forum/index.php?topic=6292.0


General Motors temperature gauge troubleshootingTemperature gauge troubleshooting begins with isolating the problem either to the gauge, sending unit, fuse or wiring. As with any electrical troubleshooting it is best to check all wiring connections are clean, tight and free of corrosion.
The following process must be preformed with the ignition key turned to the “on” position. The first place to start is at the temperature-sending unit. Remove the wire from the temperature-sending unit located on the engine (typically a dark green wire). Then connect the wire to a good ground. You can do this by using a jumper wire. Check the gauge, if the needle points to “Hot”, replace the sending unit. If the needle does not move, remove the same dark green wire from back of the gauge and connect a jumper from the terminal on the back of the gauge to a good ground. Check the gauge if the needle moves toward “Hot”, the wire from the gauge to the sending unit has an open or bad connection. If it does not move, connect a test light by grounding one end to a good known ground and the other end to positive side of the gauge (typically a pink wire). If it does not illuminate, ensure the gas gauge fuse is good.  If the fuse is good, connect a jumper wire between the ignition switch and the positive side of the gauge. If the gauge now works, replace the defective wiring between the gauge and the ignition switch. If the test light illuminates there is 12 volts present, replace the temperature gauge.

[Winnebago Warrior 94]

Thanks for the help ..diagrams  and troubleshooting tips ..I did radiator  temp test ..used digital and a metal  thermometer . .got the same readings on both ..temp climbed and stayed around 178  degrees  steady  give  or  take  a  few  degrees  every  now  and  then . I noticed the fluid  level would raise and lower Inside of radiator from time to time ..I assume that means the thermostat  is opening  and closing   properly . .the temperature  gauge  inside  never moved at all stayed 100 degrees . . I ran winnebago  for like 20 min. .
now to follow the troubleshooting  tips  for why gauge isn't working

[CapnDirk]

That's what I was looking for.  I'd say find the wire to the temp gauge next and ground momentarily to see what the gauge does.  Usually on top of the engine manifold.  Not entirely sure of your location.

[DaveVA78Chieftain]

I think the sending unit is on the left side of the engine block in between cylinders 3 and 5.

[CapnDirk]

I think you may be right.  Was coming straight out sideways from the head. 


Sad how the mind pollutes from good times to Tiny ODBII pint sized cracker box technology.


I remember when a real man could tune up the family car with a screw driver, bottle opener, and pair of pliers.  The only need of the bottle opener was to pop open the next cold one!  At the end of the day your son was in awe, and the missus was giving you that come hither look.


Now the kid jacks into his rice box with his eyephone and it's not to play tunes, it's to tweak the fuel system!   The missus is thinking you drink too much beer!


Ohh the horror of it all!

[Rickf1985]

You forgot the matchbook for setting the points.

Yea, and that kid is getting 600 HP out of that rice burner with his laptop!!! Scary.

On the later engines there are usually multiple water temp senders, one for the gauge on the dash and one for the OBDII computer. The dash sender is still in the thermostat housing and the computer sender is in the side of the head. Do not mistake it for the knock sensor with is also down there. The knock sensor has a weird round plug.

[CapnDirk]

I thought the match book was for road side filing of the points (the striker of the book)  You could set them to?

[DaveVA78Chieftain]

On the later engines there are usually multiple water temp senders, one for the gauge on the dash and one for the OBDII computer. The dash sender is still in the thermostat housing and the computer sender is in the side of the head.

Thats why I was hesitant to post pictures.   
GM used a OBD1 based TBI system from 1990 to 1995.  My 1992 wiring diagram book says the gauge sensor is the one in the drivers side head and the 1992 Emissions book says the ECM temp sensor is the one by the thermostat.  Far as I know 1994 would be the same.

As far as I know, OBD2 MFI started in 1996.

[DaveVA78Chieftain]

I thought the match book was for road side filing of the points (the striker of the book)  You could set them to?

Yep, thats a old backyard mechanic trick when in a pinch

[CapnDirk]

Hopefully the OP will nail down the exact MH info for chassis and engine.  If it's the gauge Id just go with a replacement water and oil gauge at the dash.  More accurate, and not hard to swap out sending units.  Get it over with now rather than trying to replace the dash gauge (if the gauge is the problem.


I work on small engines now, we set the gap on the magneto's with a business card 

[Elandan2]

And the matchbook cover was almost exactly .020" thick; the most common setting for point gaps.

[Winnebago Warrior 94]

Thanks for the info ..I did take the cover off the engine and I saw a green wire on one but I haven't had the time to check it out yet but plan on doing so ..we drove the winnebago  to a friend's house last weekend and all was good ..I've started laying ceramic   tile in a house and im sore all over ..but I hope to  check out the temp gauge soon ..appreciate  the help and my hubby has had to work some overtime ..good for the wallet but not good for getting  stuff done ..lol