Gauges installed...... These numbers don't seem right

[icanfixall]

A factory thresomsts starts to open at 192 degrees and is fully open at 212 degrees. Useing the head port location for your sender is going to tel you about a 7 degree higher temp than the oem location reading will. this is because the front of the block has a passageway that mixes all the coolant that the thermostat sees. Out of the heads is hotter than what comes out of the block cylinder walls. This passageway is just below the injection pump gear cover housing. Your temps sound fine.

 

[franklin2]

Yes sir. You are correct. My appologies. It is a voltage created by the junction. I mis-spoke.

I find it interesting that these things are all like type k thermocouples. I would have guessed they would be RTD's or something to deal with the specialized wire problem. Good to know. I know how to deal the thermocouples. Brings interesting thoughts to mind.

I don't know what the temp limits of the RTD's are, but that might have something to do with it. Most lower temp systems use a type J thermocouple, and the higher ones use the K. Of course there are other ones that go even higher. They make many temperature controllers and readouts for industrial applications that you could use to read the temp, the only problem is they are not 12vdc powered. With the temp controllers, you could wire it to a warning light or buzzer if it went over your EGT high limit(if you could get it to work on 12vdc).

 

[whiteboyslo]

First long trip with the gauges installed. I deliberately lugged it up a few grades just to see what she'd climb to. Water temp got to about 217 tops, but settled back out pretty quick after. Seems to like to run right at 205-207 at freeway speeds on level grade as well as stop-and-go traffic.

Mike

 

[whiteboyslo]

Bumping this old thread looking for some feedback.

Took the truck on a 600 mile-ish trip last weekend with the most load she's seen so far (under my watch anyway). She had 2 sportbikes in the bed, two more on a trailer, and a bit of gear. All told, my guess is she was towing/hauling an additional 2000-2500lbs. To say she didn't notice it would be a bit of a lie, but there was no struggling, either.

Anyway, temps on flat lands were exactly as before. She ran 200-210 depending on the grade and (seemingly) the time of day/outside temp. Heck, she even dropped below 200 a couple of times. However, on some of the more prolonged grades, she crept up quite a bit. I occasionally saw 220s and even peaked at 230 once. In most those instances, the fan kicked in (first time I've heard it do that since I installed the Champion radiator) and cooled it back off QUICK. There wasn't a set temp that it kicked in at, really, but she always cooled right back down once over the hump. The OE gauge never got over the 'O' in NORMAL and the truck didn't give any other indication that it wasn't happy.

Talking with members both on here and 'that other forum', it seems people see a WIDE range of temps coming from the same location on the engine. One member on 'the other site' used GlowShift gauges and swears that he has never seen over 200 on his gauge even when towing some very appreciable loads over the Rockies, and he has the Champion rad as well.

Any thoughts? I'm half tempted to replace the t-stat (OE Motorcraft, of course), but I've already run into a comedy of errors trying to be pro-active with work on this truck, so I'm more trying to take a 'if it ain't broke don't fix it' approach.

Mike

 

[franklin2]

Doesn't look broke to me, so I would not fix it. Sounds like the variance you are seeing is in the fan clutch and when it decides to kick on or not. At least yours works, but they are known to let the engine get near 230 before they kick in. I locked my fan so I get good cooling all the time, though probably am losing a little bit of horsepower which I don't seem to miss.

 

[jaluhn83]

I've used at least 3 different gauges (2 mechanical, one electrical) on 2 different engines and seen 190-195 anytime except under heavy load (ie, idle, flatland towing, empty uphills) and up to about 210* under load. I see the fan kick in around 205 and off around 200.

This is using the forward upper port on the driver's head which is the stock temp sender. Based on the coolant flow I'd expect this to be the hottest part of the loop (coolant flows out of the head and into the crossover passage to the thermostat here.

The lower forward port is the stock over temp sensor - stock is 241* (IIRC, can't find a reference). I have replaced this with a 225* unit. Interestingly I have had the overtemp light come on (with the 225* sensor) several times when the gauge read around 210*. I have not yet tried calibrating the gauge and sensor to see which is right or if both are and there's that much temp difference.

The thermostat starts to open at 192 and is fully open by 212, so I'd expect to see normal operating temps in the 192-200* range under light to moderate load. To me anything over 200* under light to moderate load (half throttle and below, freeway, etc) would be cause for concern though not necessarily a reason to panic. Personally I don't like to see over about 210* under load, but that's on the conservative side of safe. Up to about 225* should be fine, over that I'd be concerned. The hotter you get the less margin for error that you have, and the more everything is going to be stressed. From what I've seen also, oil temps under high load run 20-30* above coolant, so 220 water temp = ~250 oil temp which is about as high as you want to go with the oil.

At one point I did have a bad fan clutch and would see temps in the 200-205 range on the freeway with over 220 under high load. That was a completely shot clutch though.

Bottom line, if you're comfortable with those temps I think you're fine to use it, though if it was me I'd probably try to bring them down more. My guess is that your fan clutch is set for high temps than what I have and that's what is causing the temp difference.