Today on the drive from WA to CA I got a chance to play with my AE a little bit. On a whim I data logged my ECT. From my understanding because I have a 6-speed my AE can read accurate ECT. Much to my surprise I saw ECT of 240-250. I have DieselSite's 203 t-state with rotella ELC in the truck. Once I saw the ECT I pulled up my EOT and it was staying steady right above 200. I was under the impression that with a 203 t-stat I would be seeing higher temps, but I thought that they would be in the 215-220 range, not 240-250.

This occurred on completely level ground, at a constant speed, and unloaded other than myself and my two dogs. Unfortunately I have only had AE for a month, and this is the first time I have checked my ECT read out on it so I have no idea if this is a new issue or not.

Also, my sig is not up to date, I just installed a set of 250/200 injectors from FFD. I have had the 203 t-stat since august. I only data logged ECT once on the trip, but was viewing live data from it a number of times and it seemed to stay constant right around 245. Lowest I remember seeing it at was 230.

Is this something I should be worried about? I didnt hear my fan kicking on at all, but I also only have a downpipe on my truck and had the music on to keep from going insane with the drone. I can get more data logs tomorrow if need be. I am going to dual termies soon and want to make sure that I dont have a cooling issue.

Also what problems could coolant temps this high cause?

 

Definitely seems high, I assume coolant is at proper level? I would check it when the motor cools down, maybe after sitting all night, against ambient temperature to see if the sensor is biased?

IIRC the 6 speeds either use 2 different sensors one for the gauge like the autos and one for the PCM which the autos cannot see, or PCM parameters. The only time I ever heard of a 7.3 overheating was Peter(Duck Fan) going home from RRE 2 years ago, ended up being the radiator. Not that I think that is your issue, I'm betting on the sensor personally.

https://www.ford-trucks.com/forums/9...oor-peter.html

 

I've heard of it happening before when the reservoir cap goes bad. Try changing your cap first.

 

If in deed you were seeing those coolant temps, I would think you would have "lock up" of your thermostatic fan clutch. I have the DS 203* stat and usually see less than 190* EOT on 60*-70* days. I don't monitor ECT since I have an automatic.

 

First thing to fix your issue is to remove the 203 stat and install the proper 195...

 

That's what I don't understand. The majority of the drive the ambient temp can't have been more than 45-50. I would be inclined to think that I have a faulty sender for the ECT but that still does not explain the oil temps being where they were in comparison to your data.

Next question is if temps were indeed this high what issues would it cause if any? Im assuming it could result in lack of power, higher egt, and possibly more smoke? Could it also account for somewhat rough or inconsistent idle?

 

Also, any way to definitively test the fan clutch? I've replaced them before so im not overly worried but I do not want to go throwing parts at this. Granted a fan clutch may not be that big of a deal, but it can't be something too hard to test.