Coolant temp sensor issue 74 360 FE
Thread Starter
|
Senior User
Joined: Sep 2018
Posts: 128
Likes: 1
Coolant temp sensor issue 74 360 FE
Hi Guys:
Yesterday I replaced the temp sensor on my engine (360 FE). Previously, the gauge was either barely or not moving at all. I jumped the wire and got the gauge to go up when key was turned to the on position, with engine off, showing me that the gauge and wires were good.
So, assuming the sensor was bad, I replaced it. However, again, now the gauge needle barely goes up. It did go up slightly after quite a while of warming the engine. Interestingly, once engine is warm, if I turn key to on, needle goes up to where the temp was before I shut it off. In other words, the needle does not spike to the other end of the gauge even when I turn the key to on (without starting).
Wondering if there are any other ideas of what might be going on. Could it be a stuck thermostat keeping the coolant from getting hot enough, quickly? Truck runs good, otherwise...
Dave
Yesterday I replaced the temp sensor on my engine (360 FE). Previously, the gauge was either barely or not moving at all. I jumped the wire and got the gauge to go up when key was turned to the on position, with engine off, showing me that the gauge and wires were good.
So, assuming the sensor was bad, I replaced it. However, again, now the gauge needle barely goes up. It did go up slightly after quite a while of warming the engine. Interestingly, once engine is warm, if I turn key to on, needle goes up to where the temp was before I shut it off. In other words, the needle does not spike to the other end of the gauge even when I turn the key to on (without starting).
Wondering if there are any other ideas of what might be going on. Could it be a stuck thermostat keeping the coolant from getting hot enough, quickly? Truck runs good, otherwise...
Dave
Thread Starter
|
Senior User
Joined: Sep 2018
Posts: 128
Likes: 1
Quick update...I'm wondering what may be going on. Once engine warms up, I know I'm getting a little circulation...top radiator hose is hot, bottom hose is not. Top of radiator and water is hot. I also have some heat. But, with radiator cap off, I see virtually no circulation...certainly not vigorous. Does anyone know what that could be? Water pump is not leaking and there are no bearing noises that I can hear from the pump.
But, with the lack of circulation and the temp sensor gauge barely moving, could it still be a bad water pump? I don't think it's the thermostat since the upper hose and top of radiator are getting hot.
Any thoughts?
But, with the lack of circulation and the temp sensor gauge barely moving, could it still be a bad water pump? I don't think it's the thermostat since the upper hose and top of radiator are getting hot.
Any thoughts?
Senior User
Joined: Dec 2018
Posts: 152
Likes: 3
From: NEPA
I've seen water pump impellers come loose on the shaft and sometimes some of the fins rot off and both conditions would slow the circulation down quite a bit. Do yourself a favor, get a new pump and thermostat and backflush the rad, heater core and motor. Overheating can cause way more expensive damage and usually at the worst possible time.
Thread Starter
|
Senior User
Joined: Sep 2018
Posts: 128
Likes: 1
Thanks Butcher. I'm leaning towards doing all that as I'm restoring the truck anyway. Still, I'm puzzled why my temp sensor is not registering the heating up if I have low or no coolant circulation? Seems like if the engine's getting too hot, the sensor would register it on the gauge.
I know the wire and gauge are good and I just installed a new sensor yesterday. But, after starting, the gauge barely moves and after the engine is fully warmed up, it only goes up to a little above the coldest setting. I wonder if these older sensors only register when coolant is in the engine. In other words, if there's no coolant, would a coolant temp sensor be able to measure the ambient temperature of the engine?
I know the wire and gauge are good and I just installed a new sensor yesterday. But, after starting, the gauge barely moves and after the engine is fully warmed up, it only goes up to a little above the coldest setting. I wonder if these older sensors only register when coolant is in the engine. In other words, if there's no coolant, would a coolant temp sensor be able to measure the ambient temperature of the engine?
Logistics Pro
Joined: Jul 2005
Posts: 4,217
Likes: 154
You didn't use Teflon tape on the sender did you? That will make the sender not work, because the tape blocks/impedes the ground signal which the sender body gets from being threaded into the intake manifold or where ever.
Trending Topics
Thread Starter
|
Senior User
Joined: Sep 2018
Posts: 128
Likes: 1
Hi Meangreen. The unit I bought from O'Reilly's had teflon tape on it out of the box. I did not add any teflon tape. I was told this was correct procedure and that the threads on the unit would cut through the tape and make proper ground to the intake. To be honest, most of the tape came off as I tightened it and are bunched up at the surface. But, I wondered about that.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Logistics Pro
Joined: Jul 2005
Posts: 4,217
Likes: 154
Maybe it has a good radiator and a 160º-180º thermostat, and the engine really isn't getting warm enough to lift the needle any farther.
You can also try pulling the cluster, and cleaning the contact nuts for the temp gauge. Even simply loosening them a little and re-tightening might make for better contact.
You can also try pulling the cluster, and cleaning the contact nuts for the temp gauge. Even simply loosening them a little and re-tightening might make for better contact.
Cargo Master
Joined: Jul 2005
Posts: 2,309
Likes: 364
From: Kansas
how far did the gauge go up when you grounded the wire?
do you have a thermometer so you can check the actual temperature of the coolant?
I wouldn't go replacing anything yet based on your symptoms...my initial guess is that your thermostat is stuck open (or as mean stated, could be a thermostat with a lower temp value)
do you have a thermometer so you can check the actual temperature of the coolant?
I wouldn't go replacing anything yet based on your symptoms...my initial guess is that your thermostat is stuck open (or as mean stated, could be a thermostat with a lower temp value)
Thread Starter
|
Senior User
Joined: Sep 2018
Posts: 128
Likes: 1
Hey dlburch...when I tested the gauge/wire by grounding, the needle went all the way up with ignition on. When I turn ignition on now with the new sensor, it only goes up to whatever it is registering for the temperature.
My only question about a possible stuck open thermostat is wouldn't I see flow in the radiator if that were the case? When I take cap off and observe, basically, if the coolant is moving, I can't really detect it from the cap opening. Maybe that's how it works? I don't know.
Thoughts?
My only question about a possible stuck open thermostat is wouldn't I see flow in the radiator if that were the case? When I take cap off and observe, basically, if the coolant is moving, I can't really detect it from the cap opening. Maybe that's how it works? I don't know.
Thoughts?
Laughing Gas
Joined: Nov 2013
Posts: 1,207
Likes: 60
From: S.E. Louisiana;so far USA
My only question about a possible stuck open thermostat is wouldn't I see flow in the radiator if that were the case? When I take cap off and observe, basically, if the coolant is moving, I can't really detect it from the cap opening. Maybe that's how it works? I don't know.Thoughts?
An ohm meter should be able to tell you if there is a good connection between the body of the sensor and the engine.
Logistics Pro
Joined: Jul 2005
Posts: 4,217
Likes: 154
It's only newer vehicles which need to wow us with mostly needless gauge needle sweeps, as everything powers up.