how much time before 7.3 is warm? outside temp now 10*C

[Bart F-350]

It seems I fall from one issue in another one...
While running my test drive today I noticed that my water temp gauge is reading fairly low, actually not even coming onto the scale. it just leaves the letter C, and not coming into the scale which reads "Normal".
I did measure the in and outgoing hoses, ingoing at top of the rad. read 65*C and outgoing 35*C
due to registering issues I cannot take yet a good testdrive with highway and so, but I had the Idea that the temp should read higher then what it does now?

So therefore my question, how long it takes (normally) before the 7.2 is at operating temp? outside temp now 10*C =50*F

 

[u2slow]

Diesels are cold-blooded. Imho, the cold idling downsides outweigh any benefits from it finally building a little heat.

Better to let the block heater do the work for an hour and maybe run it for 5-10mins.

 

[DrCharles]

It usually takes mine a good 10 minutes if not longer, before I start to feel heat from the heater (and the gauge rising off C). Although it's a 20-25 mph drive for the first 2.5 miles on dirt roads before I get to the highway, so the engine has very little load...

 

[asmith]

First those gauges really show you anything. The needle can be in different parts of the gauge truck to truck and it be the same temperature.
Now I converted your Celsius to Fahrenheit so I knew what you were dealing with. Comes out to about 149 degrees. So definitely on the cold side. How long were you driving it? if it is just idling it may never reach operating temperature. You need to drive it for 10-15 minutes I would say. When I just drive mine across town which is less than 10 minutes the needle barely moves unless it is summer time.

 

[Rocknit4x4]

Ambient temperature outside today at my location was low 40*F. I drove the truck a few miles from the house on city roads and it got up 165*F. Once i got on the interstate it warmed up to about 175*F and it doesn't get much above that until the ambient air warms up (driving unloaded). In the middle of the summer in stop and go traffic i barely see above 185*F.

On my truck, the N in NORMAL is about 185*F. I have see it get up around M which was 205*F and once, when I lost all the v belts, it got up to the L right about when the aux temp warning light came on - about 240*F.

Like others have said, factory gauges aren't very reliable (why i put an after market one on). Also, i have a Mishimoto 3 row radiator, 13lb cap, new fan clutch and an upgraded fan wheel from 03WR250f (on this forum) - so i know my cooling system is working well.

Having said all of that, i generally get a little heat out of the truck around 140F / 150F, but it doesn't really heat up the cab till its in the 160s and on high for the blower for a while.

 

[Bart F-350]

If so, I might start experimenting with cardboard before the radiator.
and I have to have some more patience, since France is very difficult with registering US vehicles, For me it turns out to be a multi year event, and I'm almost there, I need to go somewhere in January to have the annual inspection done (this will be the first in many, many years, and that will pass as a acceptance test before I can get the French equivalent of a valid road registration with it's own plates) and only then I have the legit possibility to start driving around and monitor it's temp. behaviour.

 

[Black dawg]

Would be better to start cold and let it sit and warm up, to see what temperature the upper hose starts getting warm.

Sounds like from your description that the thermostat is either leaking or opening early.

 

[snicklas]

As others have said, it all depends on outside temperature.

On my 6.0 Excursion (I know, not and IDI, but still a big V-8 diesel) that has had the EGR Deleted for at least a decade, is, if it is below about 40 degrees F, it WILL NOT see normal operating temperature. I’ve had times when it is in the teens and lower, that I have driven it 30 miles on the interstate, and have stopped at a gas station and it will kick up to high idle because it is still running so cold. It’s not ar thermostat issue, it’s been replaced with a tested good one. Mine was designed to have an EGR cooler in it, and pull all that excess heat out of the coolant. When the EGR was there, it ran normal temp, no matter the ambient temp. This is just the 8-9000lb truck, no towing..etc

Now I did have a emergency the other day and it was fairly cold out, and I did see normal operating temperature…. But with you foot on the floor…. It will make heat….

 

[Cant Write]

Both my van and my TDI (BHW) will produce warmish air while idling during cold warm up. But it takes awhile.

My TDI still has its factory EGR cooler at 213k miles and keeps its operating temp much easier once driven. It will cool per the gauge on long Mtn descents.

My van is all over the place depending on incline, decline, flat. I can physically watch the temp gauge move and the thermostat open or close. But it always has heat through the HVAC system. I need to buy a winter front.

 

[KansasIDI]

I am beginning to question the quality of the Motorcraft thermostats. I put a new one in when I did my engine, tested it in a pan before I put it in, and after you start it and let it idle to warm up, it will get up to temperature and then drop back down. I can’t figure out why it would do that…

I too, am in search of a winter front, but they seem to be very hard to find for these bullnose trucks

 

[FrozenMerc]

I don't have an actual temp gauge, just the stock Ford jobby. That said, I drove 35 miles yesterday, around Springfield, all in-town, stop-and-go driving, with an ambient air temp that was hovering between 32 and 35 deg. F. The needle barely wiggled off of "cold", but I had good heat out of the vents, so I know the thermostat at least was partially opened, and that is good enough for me. I do have a winter front for it, used it quite a bit when I lived in NW Minnesota. Those days when the high temperature outside was -15, it was an absolute necessity. Not so much in SW Missouri.

Kansas - What you are seeing happen is when the thermostat first opens, it lets all that cold coolant that has been sitting in the radiator through, and it is typically enough to cause the thermostat to close again. This normally happens a couple of times until all the coolant comes up to temp. Back in my powersports Test Engineer days, we were testing a new Yamaha engine. If the SxS got driven through a puddle such that the engine or rad were cooled rapidly by the splash, the thermostat would close so quickly, that it would setup a water hammer effect within the cooling system, and in some cases the water hammer would actually knock the pump impeller off the shaft. We ended up having to install a pressure relief valve to save the pump.

I purchased my Winter front through the local Auto Value parts store back in Minnesota. Takes a good parts counter guy to know where to find it.

 

[Bart F-350]

I am beginning to question the quality of the Motorcraft thermostats. I put a new one in when I did my engine, tested it in a pan before I put it in, and after you start it and let it idle to warm up, it will get up to temperature and then drop back down. I can’t figure out why it would do that…

It is a bit logic though, you have the small circuit which warms up first, then the thermostat opens and cold fluid from the big (radiator) circuit flows in, and that makes the thermostat close partially(or maybe completely?) until it's again at it's opening temp. and then it reopens, and so on and on until the whole circuit (small and big) is at operating temp.

 

[KansasIDI]

It is a bit logic though, you have the small circuit which warms up first, then the thermostat opens and cold fluid from the big (radiator) circuit flows in, and that makes the thermostat close partially(or maybe completely?) until it's again at it's opening temp. and then it reopens, and so on and on until the whole circuit (small and big) is at operating temp.

I don't have an actual temp gauge, just the stock Ford jobby. That said, I drove 35 miles yesterday, around Springfield, all in-town, stop-and-go driving, with an ambient air temp that was hovering between 32 and 35 deg. F. The needle barely wiggled off of "cold", but I had good heat out of the vents, so I know the thermostat at least was partially opened, and that is good enough for me. I do have a winter front for it, used it quite a bit when I lived in NW Minnesota. Those days when the high temperature outside was -15, it was an absolute necessity. Not so much in SW Missouri.

Kansas - What you are seeing happen is when the thermostat first opens, it lets all that cold coolant that has been sitting in the radiator through, and it is typically enough to cause the thermostat to close again. This normally happens a couple of times until all the coolant comes up to temp. Back in my powersports Test Engineer days, we were testing a new Yamaha engine. If the SxS got driven through a puddle such that the engine or rad were cooled rapidly by the splash, the thermostat would close so quickly, that it would setup a water hammer effect within the cooling system, and in some cases the water hammer would actually knock the pump impeller off the shaft. We ended up having to install a pressure relief valve to save the pump.

I purchased my Winter front through the local Auto Value parts store back in Minnesota. Takes a good parts counter guy to know where to find it.

I understand these phenomena. But I drove for three hours yesterday, and after the thermostat opened it closed, and never did reopen again. I checked it with a gun and it only got up to about 145° after the thermostat closed, and this was while towing…

On warmer days i.e. 50 to 60°, then it will repeatedly open and shut as it seems.

On hot days i.e. 80 to 100° it will get up to about 180° and stay there

 

[Cant Write]

I think you have the IDI hacked is after for his demo derby

 

[IDIBRONCO]

I might start experimenting with cardboard before the radiator.

I need to buy a winter front.

I too, am in search of a winter front, but they seem to be very hard to find for these bullnose trucks

My Blue Truck started acting up in colder weather. It acts like the thermostat is open. I replaced the thermostat last winter and the old one was closed when I removed it. I still put a new one in since I was already to that point. The new one acts just like the old one did. It seems fine until the temps get down into the 30's. I just do the cardboard trick for the winter time and pull it back out in the spring. Probably almost three years ago now, I left the cardboard in front of the radiator for longer than I had planned. I got a call from a friend and drove to meet him and his wife to eat. It was in the lower 80's and there was a pretty good wind blowing that day (probably 20 MPH). The needle on my mechanical temp gauge stayed right above the 190* mark like normal. The only time that it showed hotter was when I turned easy and had the wind blowing from the side. Then it got to maybe the 200* mark. That was empty. I don't tow very often so I don't have much input in that regard.