Packard Forum Index » Post-War (1946-54)

My 1950 Deluxe 8 has the original Packard gage without numbers so I wanted a more accurate gage as a backup. I bought a new old style Steward Warner "wings" mechanical temp gage and put it in a bracket under the dash. It looks very nive and retro but gives erratic readings. I put the sender in a tee fitting at the outlet of the water pump because I could not find another location on the engine. The tee fitting is to supply water to the heater. I almost can say the gage sender is in the heater hose rather than in the engine coolant flow. The erratic gage readings seem to improve if I turn the heater on, but who wants the heater on in the summer?

Does anyone have a suggestion for a better location for the auxiliary temperature gage. I do not want to abandon my original gage because I like 2 readings to be safe. My problem seems to be in the tee fitting. The sender probably sits in an air bubble and the readings are quite low and vary as you drive or as you turn on the heater.

I don't really have any good ideas for you. Probably the reason for the erratic performance with the hookup to the heater hose is that when the heater valve is closed, there is no water flow at that point so the sender is just sitting in a stagnant pool of coolant. I've seen folks extend the temp sender opening in the rear of the head with a short nipple and a "tee"; same problem, then neither sender is in the direct path of coolant flow.

I would also think the one proper head location might have issues housing two sensors. Think others have used a tee but for only one large sensor. Not sure how well it works because of the problem O_D mentions. There's at least one way to do it with the flow in the heater hose as you have tried but would require a different location and some extra plumbing.

Since you have a 50, am going under the assumption you have the engine compartment heater with the thermostatically controlled heater valve. It should be possible to tee a complete second small loop with a restriction allowing just a minimal flow thru the tee containing the sensor -- barely enough to keep the sensor "current". The heater would still get the majority when needed. If that flow wasn't sufficient to keep the gauge correct and more would compromise the heater, there are heater control or diverter valves which bypass the full regular heater flow thru a second loop. If you were interested in either approach, perhaps that extra plumbing could be hidden under the heater box, fender or floor.

I installed an auxillary gauge set for temp and oil pressure on my 47 Clipper Custom. I installed the gauge set on the bottom of the ash tray, where it is easy to read, but can be removed without evidence, should a future owner wish to do so.

I connected the mechanical water temp gauge to the fitting on the back of the cylinder head were the heater hose valve is located as I wanted it to sense the warmest part of the system. I placed the gauge so that it was in front of the shut off valve. It seems to work well, giving good temperature readings.

The connection for the mechanical oil pressure switch is to the rearmost plug on the main oil gallery.

I retained the original gauges and connections, but they seem to read too low. I rely on the auxillary gauges for correct readings.

(o[]o)

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That is a decent place. Does the sensor end stick down past the tee to actually get a little of the water flow in the head when heater valve is off or is it all by convection and heat of the head?

Howard,

I don't recall the length of the tube's bulb, but think it does not extend past the 'tee' into the head. How much circulation takes place here is hard to tell (especially with the heater valve in the closed position), but probably not too much. I was concerned about getting an accurate water temp reading, but decided to try this location and see what would happen. The auxillary water temp gauge was connected where the original gauge was fitted (rear of head on driver side), but I wanted to keep the original gauge connected. The readings at the old and new locations are the same.

(o[]o)

I appreciate the help and advice. The only other place I could think of was to weld a fitting into the tube between the lower water hoses. Unfortunately my gage sender will not reach to that spot. I think I will try to get a tee that goes in the head under the stock sender I will pay attention to where the bulb ends up and make sure the bulb does not block all the flow to the heater.

Other suggestions are still appreciated.