7.3L 2002 F350 Overheating - Ford Powerstroke Diesel Forum
Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
LinkBack Thread Tools Display Modes
Old 06-10-2013, 07:08 PM
Powerstroke.org Rookie

Join Date: Jan 2007
Posts: 22
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
7.3L 2002 F350 Overheating

Hi guys,

On a recent trip, I had some over heating issues with my 2002 F350 7.3L Diesel. Truck is stock with a DP Tuner in it for Economy. Truck has had a very easy life for the most part.

I was pulling a 3000lb load, and had my coolant gauge, much to my surprise, rise and almost peg out to H (I let off it before that happened). Any uphill incline or if I stayed on it above 70~ MPH, I'd see the coolant needle temp climb rapidly.

We limped the truck back and home, not letting it overheat.

Once I took the trailer off, the truck temperature behaved normally. I could cruise on the highway and it never reached above the middle range.

I had taken the same trailer/load on a similar trip two weeks before this, and had no issues.

No coolant leaks that I can see, my overflow tank was still full. Truck had some water dripping out the passenger side, but this appeared to be from the A/C running.

I've replaced the radiator cap, and I have a new thermostat to install.

I took a look at the fan clutch, and after letting the engine warm up, I am able to turn the fan by hand with the engine off. It was suggested to me that this is indicative that the fan clutch is shot.

Any other suggestions on what to replace? Really hard to get confidence I've fixed it, as it only happens while towing.

I appreciate your guys help!

Reply With Quote Quick reply to this message
Sponsored Links
Old 09-08-2013, 05:56 PM
Powerstroke.org Rookie

Join Date: Sep 2013
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews

hi I am having the same problem on my 2001 7.3 did u ever figure your problem out thanks
Reply With Quote Quick reply to this message
Old 09-08-2013, 06:10 PM
Compression Ignition Addict

Join Date: Feb 2009
Location: Nacogdoches, TX
Posts: 11,079
Thanks: 0
Thanked 14 Times in 14 Posts
Feedback Score: 0 reviews
You had a coolant gauge? Aftermarket or just the dash gauge?

7.3s RARELY overheat. I would of course check coolant level. Thermostat usually sticks open, causing low temps instead, but doesn't hurt to replace it.
Fan clutch should be making that fan roar. In 100*F temps and AC going, my fan clutch kicks in after some hwy cruising, and then stopping and starting again. It's obvious it's pulling extra air.

I would even guess maybe your ECT sensor is bad.
Is your coolant clean or oily?
Reply With Quote Quick reply to this message
Old 10-05-2014, 09:28 PM
Powerstroke.org Rookie

Join Date: Oct 2014
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews

Did you figure out the cause of your overheating issue? I have a similar issue that just happened today!! I am hoping to get some info ASAP. I might need to get it into a mechanic as I just don't have the time to deal with it!

My 2002 F-350 7.3L overheated on me for the first time today. I was towing heavy, and it was hot, but I’ve towed heavy in the heat before. The temp gauge hit H on pulling a hill (I must have not looked for a few minutes), and I immediately backed off the throttle and turned the heater on high to dump the heat load. There was also some intermitent high-pitched squealing that seemed to start only as the truck was very hot.

Engine is stock with an Edge Evolution programmer in Stage 1. Truck has 176,000 miles.

No obvious coolant leaks.

No white or other odd smoke, just some very light sooty exhaust.

The coolant level in the overflow tank has never stayed at the “min” mark, which of course I’ve always been curious about, but I have not had issues in the past. So let’s say I fill it up to Max at cold temp, after driving, it will be below the Min line, even when hot. Have never noticed any leak. And it has never dropped below the mark that it “settles” at.

New water pump at 148,250
New 203deg thermostat from Dieselsite.com at 148,250 miles
Coolant flush at 148,250

Used Fleetrite ELC coolant as per:
Fleetrite ELC is approved and suggested by International. Can get from an International dealer. Same as Rotella ELC. Supplied to International by Shell. These are OATs. Definitely 2/99 and up are okay for OATs (but not pre 2/99 as some seals etc. were updated after this point and pre-2/99 were not hence the incompatibility). Can also use CAT ELC, Mobil 1 ELC, Prestone HD ELC, Zerex Extreme ELC, Peak Final Charge ELC.

New de-gas radiator tank (had some cracking - I was thinking/hoping this was why my coolant level would never stay full, but it didn't change anything), upper and lower degas bottle hoses, & new radiator cap at 152,000

New OEM Motorcraft fan clutch at 170,000 miles - this actually jumps out at me as the thing that “changed” most recently and might tell me something. This was the first time towing with the new fan clutch. The old one was definitely stuck on, so I’m wondering if this confirms that I have always had a cooling system issue, which has always been “offset” by the malfunctioning fan going 100% full-bore at all times, and now that the fan is actually operating per spec, the coolant system issue is rearing its head?

Thanks for any info!!!

- Danny
Reply With Quote Quick reply to this message
Old 10-11-2014, 07:39 PM
Powerstroke.org Rookie

Join Date: Dec 2013
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Tagging along. I am having very similar issues with my 01 excursion, it only goes up to the red when towing a 5k lb trailer uphill, and only once in a while. New motocraft Tstat, coolant flushed, new reservoir tank, fan clutch seems to be functioning fine (doesn't spin easily when turned off), also noticed that the upper hose one morning was flat, that was the day I replaced the Tstat and never saw it flat again. The old stat wasn't stuck when I pulled it out, either, just old and not an OEM unit.
Could this be the tranny heating up, transferring heat to the motor? Would I benefit from a 6.0 tranny cooler mod, even not knowing what the tranny temps are? Or, could I need a new water pump or radiator? 200k on the OD, trans was rebuilt by AAMCO at 150k (previous owner), doesn't lose any fluids and runs fine otherwise. No tuner, it's bone stock.
Reply With Quote Quick reply to this message
Old 10-11-2014, 08:48 PM
Powerstroke.org Sponsor


Join Date: Apr 2010
Location: Defiance
Posts: 5,116
Thanks: 472
Thanked 153 Times in 144 Posts
Feedback Score: 1 reviews
could be the water pump going out. Its very difficult to overheat a 7.3 with 8 gallons of coolant capacity.

You can always benefit from a 6.0L trans cooler. I carry OEM 31 row for $375+shipping
Reply With Quote Quick reply to this message
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -8. The time now is 05:34 PM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.