Have a 2004 F150 with the 5.4. Got to wondering how accurate the OEM water temperature gauge is. Once the truck gets to operating temperature, it never rises above the middle point, even when pulling a trailer.

I recently added a dual gauge pod on the driver's pillar. I installed an Autometer Z-series transmission temperature gauge and plan to add a differential temperature gauge (recently added the Mag-Hytec differential cover that has a temperature sensor port). However, I'm beginning to wonder if I need to add a good engine water temp. gauge instead.

Any input? If yes, would you recommend the mechanical or electrical engine temp. gauge? Thanks.

 

The guage doesn't always run in the middle. Mine very definitely told me when my thermostat started sticking as it would not come up to operating temperature (my 02 5.4 did the same thing). My guess is that if it will show the coolant at less than desired temp there is no reason it would not also show it at over the desired temp, although like you I have never seen it.

The truth is that with the towing package these trucks have pretty awesome cooling systems and there is really no reason for them to run "hot".

BTW a sticking thermostat that lowers the operating temp can play havoc with fuel economy, especially in cooler weather.

 

Several people have posted in this site saying that the gauges in the f150 are really just fancy idiot lights. They read low, middle, and high only. I tend to support this conclusion as I never see any of the gauges moving after you start the truck. They go to the middle and stay there except of course for the fuel gauge. That has a tendency to drop quickly!

 

go for the edge, got the guages that you need......

 

Anyone with higher mileage losing oil pressure according to the guage? Unless there's a thermostat problem the temp shouldn't ever change. Have you seen the size of the rad?

 

I don't believe for one minute that the gauges are nothing more than idiot lights. When you change your oil see how long under cranking with the foot to the floor it takes for the oil pressure to come up. As far as temp when my ac is off it is very slightly to the left of the mid point. Very slightly. Why would the temperature creep up when towuing, obviously in the 5.4 the cooling system, oil cooling system and tranny cooling system are more than adequate. The tow package upgrades the cooling system. Why is it everyone expects the truck to be inadequately engineered. The truck under full tow configuration is rated beyond 9k lbs. I would hope they designed everything to meet this spec.

So until someone can present proof that the gauges are inaccurate, it's all BS!
I tow over 7K lbs and I am happy Ford designed the cooling system to be more than adequate.
The only time I would expect the temp guage to start showing other than what it does in normal condition, is when you are starting tio have a cooling system issue.

Oh yeah why do you think you have a thermostat, by definition it should control the engine temp on a consitant basis.

 

What proof do you want? Ford found years ago that people don't like to see variation in the temperature gauge, so they are dampened to the point that they only show major changes. The thermostat controls the temperature range, and does not maintain a constant temperature. The temperature varies with load, and it also cycles. The thermostat is active over a 15°-20°F range. In other words, the opening (and flow) of the thermostat changes with the temperature (in that range). If you put a thermocouple at the thermostat, you will see the variation.

 

With no temperature graduations on the gauge it's hard to tell an actual temperature.

So a 20 degree swing may not register. Also if it just an "idiot light", why does it rise slowly when cold? Why wouldn't it just jump to the 1/4 then 1/2 mark, or where ever your gauge sits?

I can see temp changes on my gauge when towing. With my 94, I could see the gauge change when the T-stat opens and closed, even if I wasn't towing. And I knew when the temp sensor needed to be changed becuase the gauge always read low. And since I used a 3 dollar after-market replacement, I got to change it twice in one year, second replacement was an OEM part.

Since I'm seeing changes on my gauge when towing, that must be when my t-stat opens and closes.

Steve91, from what I've seen, the temp gauge is a gauge, not an idiot light. It may not show every little change, but it works.

As for the "proof" you mentioned, and not wanting to **** you or anyone off....

How about an engineering report stating what you say to be true. Or maybe an internal Ford memo stating what you claim. Just saying Ford does this or Ford does that, does not make it a fact.

If you need to see every little 20 degree change, install another gauge. But make sure it's digital. The analog one may not have the resolution you need.

 

Many of the newer vehicles have a temp guage that only registers halfway when warmed up and wont show anything else afterward until the vehicle is actually overheating. This was done due to so many customer complaints of normal heatups due to use of air conditioning, and other heavy loads in the summer months. We had to deal with many of these compliants and had to try to convince the customer that a 20 degree increase was normal, even though the gauge CLEARY showed the temps in the NORMAL range on the guage. So to alleviate this problem they made the guages work normally up to normal operating temp and they just hold until an over normal temp condition exists. I was only able to find this information by calling hotline as I did not find it in the service manual.

I believe the first vehicle this was used on was the SuperDuty on the transmission temp guage, and merged to Focus and then on to other vehicles with the latest electronic instrument clusters.

 

Wildcard, did you even read my post? Where did I say it was an idiot light?

I said it was DAMPENED to only show major changes.

 

I had an Explorer with higher mileage and the oil pressure was just slightly lower one day, and stayed there. I took it in thinking the gauge was accurate and perhaps my oil pressure was starting to slip due to a weak pump (truck had 100,000 miles at that point), and they replaced only the sending unit and it came right back to where it always was. I assumed that the resistance changed or something, but I do watch the gauges. I noticed on my '05 5.4L the other day when the thermostat opened and closed. It was a cold day and the gauge was running very low, then pop, it went back to normal, just off the halfway point. So I know something happened.

 

Sorry guys but from a ford tech the water temp and oil pressure are nothing more than an idiot lite with a needle hand on it, have you ever seen any engine that would run the same oil pressure on idle as it would at 80MPH??? Get in any GM truck and you will see the guages move with differing conditions oil pressure will go down at idle from 70mph water temp will do the same depending on weather conditions!!!!!!!

 

My info is from ford engineers (and experience), not techs. I agree that the oil "gauge" is a fancy idiot light, but the temperature gauge has SOME purpose. Not much.

 

 

Did you read my post? I never said YOU made mention that it was nothing but an idiot light. I was basically agreeing with you. My request for proof from you was AFTER comments about the gauges/idiot light stuff.

What I asked was where did you get your info, about gauge dampening, and can you back it up. As I said, the "Ford did/says this" stuff means nothing if you can not back it up.

There is some much hearsay when it comes to this stuff. Yes my temp gauge moves, not much, but it does. And no, it appears my oil pressure gauge does not move. And yes, my GM car's gauges have more movement, the oil gauge does move with changes of engine speed.

I spend more scan time looking at the rpm and speedo than anything else.