ez_lle71

Hi, I pulled the radiator when i did the KDP repair. of course i used new antifreeze when i refilled it. I just have noticed that the temp gauge goes up to the middle then drops back. I know it is supposed to do that, but it cycles alot more than before. I just wondered if any of ya'll have noticed the same thing when you change your antifreeze? I do liken to see it move because you know the thermostat is working. Thanks guys!
ez

Bob Beauchaine

My stock guage does that even with the latest thermostat from Cummins. My aftermarket will only move about 2 to 5 degrees max at the same time. With my fan on I see a steady 175 even with the air on and the temp over 100.

Bob

BearKiller

This must be a Dodge gauge thing.

My F-350, with a cheap 180* STANT thermostat, will never move from 175*, loaded trailer in 100* heat, on the mechanical gauge, while the factory Ford gauge stays steady centered on the "N" of "NORMAL".

Whereas, the factory gauges, in my Dodge fleet, move dramatically with the openings and closings of the thermostat.

jimlj

Hey BearKiller,
Did you use the Dodge sending unit when hooking up to your Ford gauge? My temp never even gets up to the "N". I wonder if I should get a Ford sending unit and install it?

BearKiller

Since the gauges are Ford, I used the Ford senders, a simple matter of using NPT adapters, as the Dodge/Cummins holes are one size bigger than the Ford/Internationals.

ez_lle71

I hope you guys didin't think i was complaining?! I just was observing that with new antifreeze i saw the gauge move with the thermostat cycling more than with old antifreeze. It usually settles down after 10 to 15 mins. I saw the same thing with my dad's 95' about 2 years ago when we had to replace the radiator.(radiators don't like when a T post gets in between them and the fan!)
ez

RuralCruiser007

When you refilled the antifreeze, did you take the vent plug out of the cylinder head? This lets the air out of the cylinder head and makes the guage fluctuation less(it still does happen due to you can't get all the air out this way).

BearKiller

Pictures PLEASE.

RuralCruiser007

I dont have a pic right now, but I can tell you where it is. Where you thermostat mounts to the head, on top of the head right close to it is a plug that will accept a 3/8" ratchet in it. I use and extension and ratchet. Have that plug removed when you are filling the rad. When the antifreeze starts to come out of that hole then insert the plug back in and you will have a lot less air in the system. HTH

Glenn

BearKiller

That sounds like the plug that I removed to install my temperature gauge probe, just behind the engine lift ring thingie.

RuralCruiser007

Yup that would be the one.

RuralCruiser007

Now for remounting your temp sending unit. There are at least two other pipe plug holes in the cylinder head, on the intake side. They both are fit for the 3/8" ratchet. They are underneath the "intake". I will take pictures tomorrow night and post them this weekend.

Long story short, due to the PO having the stat in backwards I am installing a new cylinder head cause it is cracked and I am seeing wild guage fluctuations and am injesting antifreeze. This after rebuilding the engine and installing two pistons. Oh well leason learn, but still worth it.

BearKiller

Actually, due to the up high and dry location of that plug, behind the thermostat, I don't think it is the best place for a temperature probe.

Mine will not function at all, should an air-pocket get up in there, like it would should all the antifreeze start pouring out on the ground.

I am contemplating swapping holes with the factory one, down lower on the left side.