7.3 IDI w/ banks turbo overheating

Cole Roberts

Registered User
Joined
Jun 4, 2020
Posts
15
Reaction score
9
Location
Reno
First post, looking for some help.

I have an 89 F250 with a 7.3. I recently added a banks turbo on it. While I was doing the turbo I also replaced the thermostat (with a motorcraft thermostat) And did a radiator flush.

For the first two weeks the truck ran good and cold with no issues. About 190 degrees. (I installed a mechanical water temp gauge.)

A few days ago I went to tow my ski boat with the truck. Which is about 5,000lbs, I was on the freeway for about 15 miles doing about 60MPH and my water temp gauge crept up to about 220 before I pulled over. The truck cooled down while idling. And I was able to get to my destination before it got too hot again. On my drive home without the trailer it got hot again, about 220. I got a coolant meter and tested my coolant. It was rated about -35 so I drained about a gallon and a half and added distilled water. It now reads about -20.

I drove it about 15 miles the next morning to work and it stayed cool, about 190 the whole time. When I got off work I ran multiple errands around town which consisted of freeway and street driving and it never got hot. But when I was driving home which is all freeway it got hot again. I pulled over and let it cool then limped home. A few hours later I drove it on a rough dirt road, so I was going slow, for about 45 minutes and the temp never went over 190.

My dipstick and oil cap look good. I am planning on getting test strips for my coolant to see if there is any hydrocarbons in it which would indicate a blown head gasket. And or will try anything else that might indicate a blown head gasket that you guys know of. And maybe a cavitation year? Other than that I am stumped. In the 9 years of owning this truck I don’t think I’ve ever actually heard the fan turn on. But it has never had an overheating issue before. Maybe I need a more efficient water pump with the turbo? And or radiator?

I’m hoping someone else has had similar issues before I start replacing stuff. Thanks In advance.
 

franklin2

Full Access Member
Joined
Feb 24, 2009
Posts
5,161
Reaction score
1,385
Location
Va
Had the same exact issue with my 89. Running around empty, it would be fine. Get out on the highway it would start to heat up. Put a load behind it, it would heat up fast. Tried a new radiator, didn't fix it.

Ended up being the fan. It would never lock up. I was going to get a new clutch for it, but I heard so many people complaining the new ones didn't work, or the truck really had to heat up before they would kick in. So me being cheap, I made some brackets and locked the clutch so the fan was driven all the time. No more heating problems. I can pull the max load in the hottest weather, and it will not overheat. I do have to make sure I am keeping it revved up good when going up a mountain, and it stays cool. I f I start lugging it, it will start to heat up again.
 

Cole Roberts

Registered User
Joined
Jun 4, 2020
Posts
15
Reaction score
9
Location
Reno
If you don't have much or any dampness around the spring and aren't ready to spend on a new clutch you can try adding fluid as this member did. He discusses it in other threads a year or so later and says his good results continued to last.

The $4 Fan Clutch Fix

https://www.oilburners.net/posts/755468/


Bad fan clutch. Is there oily dirt on the spring on the front?

Thanks for your replies fellas. I will check tomorrow for oily dirt on the spring. I would be okay with buying a new one. Any recommendations on what brand of one to buy? I hear some people have had troubles with the aftermarket ones they have bought.
 

Black dawg

Registered User
Joined
Jan 9, 2006
Posts
3,995
Reaction score
703
Location
sw mt
getting hot at highway speeds with no loads, I would be pulling and testing that t-stat.
How well does your a/c work at low speeds?
Also check for radiator plugging....internal and external

I had a fan blade on my truck that even with the clutch mechanically locked I could not hear it. I wish I would have written the part number down before I scrapped it. I replaced it with a blade from another truck (86) and suddenly I had a noisy fan and no more overheating issues pulling heavy.
 

david85

Full Access Member
Joined
Feb 21, 2008
Posts
4,820
Reaction score
1,083
Location
Campbell River, B.C.
I used to run my truck in the winter with the fan removed. I never had overheating problems at speed, but I was towing relatively light.

I did however have these problems when I ran an aftermarket thermostat. Any load, hill climbing at speed, etc, and it would get hot. That was before I learned to only use ford/motorcraft/international thermstats on these engines.
 

Cole Roberts

Registered User
Joined
Jun 4, 2020
Posts
15
Reaction score
9
Location
Reno
Replaced the fan clutch, drove it ******* the freeway yesterday, no load, but it was a hot day and it stayed nice and cool. About 190 degrees I’ll hopefully pull a trailer today and really put it to the test. Thanks for all your help!
 

homelessduck

Full Access Member
Joined
Oct 2, 2009
Posts
2,708
Reaction score
298
Location
OR
Replaced the fan clutch, drove it ******* the freeway yesterday, no load, but it was a hot day and it stayed nice and cool. About 190 degrees I’ll hopefully pull a trailer today and really put it to the test. Thanks for all your help!

What clutch did you end up going with?
 

aggiediesel01

Full Access Member
Joined
Dec 29, 2016
Posts
531
Reaction score
417
Location
Houston, TX
Did you hear the fan roar when you fired it up cold and then go quiet after warming up a few minutes? And then did you ever hear it come on after you got it out on the road and hot?
 

genscripter

Full Access Member
Joined
Nov 22, 2014
Posts
584
Reaction score
358
Location
Inglewood, CA
Did you hear the fan roar when you fired it up cold and then go quiet after warming up a few minutes? And then did you ever hear it come on after you got it out on the road and hot?


I doubt his fan clutch engaged, but the new clutch at least has some rotational resistance allowing it to cool slightly better under no load.
 

franklin2

Full Access Member
Joined
Feb 24, 2009
Posts
5,161
Reaction score
1,385
Location
Va
I know you guys are hinting that at highway speed with no load just empty, it should cool with no fan at all. I agree, you would think with the large frontal area and all that air going through the radiator, it would stay cool. But not so on my truck. That is what threw me off for awhile and why I was changing other parts. For some reason I can't explain, on a hot day running down the interstate, you are on the throttle all the time and it will get hot unless the fan is helping out.

On a hot day, it seems like the temperature gauge is directly hooked to the throttle, no matter how fast you are going.
 

Forum statistics

Threads
91,217
Posts
1,128,517
Members
24,045
Latest member
Ramtough01

Members online

Top