Question about operating temp

[freebird01]

Ok....here is what i got...88 7.3L w/94k on the clock and a banks wastegated turbo. the truck is an ext cab long bed 4x4 w/ ZF 5speed and 3.54 gears..

when in just running back and forth to work (55-60mph) it runs consistantly 190* at temp. on the highway it will climb to 200* and pretty much stay (65-75mph).

now when im towing it stays firmly planted at 200*-210* and when going up hills i really got to watch cause it can climb fast and will easily hit 230*. then i end up about half throttle babying it tryin to keep the engine temp down in second gear....

now i watch my egt gauge and have no issues with egt....900* is usually the most i will see and thats really into it...

i do my absolute best not to let it go over 230*...

now the truck has a new radiator and a new fan clutch in it.....coolant looks fine as does the oil so i dont think its cavitation and the truck doesnt smoke at all so i dont think its a headgasket....

what do you guys think? and when it does this its not even a heavy load....just my 10k-lb 16' equipment trailer and my samurai so total it may be 5000lbs

im thinking about rigging up a dual electric fan setup in front of the rad and a/c condenser out of a pair of ford taurus fans...but im just wondering if this is the right approach or is it a bandaid...

 

[FordGuy100]

Well, driving around it sounds like the temp is normal. But for pulling that weight, pulling grades sounds like your temp is way out of line. Might be a bad thermostat . How steep are these grades? Pulling that weight in second gear with the gears you have sounds like its crazy steep/long.

 

[freebird01]

they are some good long grades but im only dropping gears so im not workin the motor as hard so the coolant temp drops...if the coolant temp would stay ok it could hold 4th gear most of the time....maybe down to 3rd at most...

typically what happens is the temp willcome up and then goin down the other side with no load it will cool off very quickly back down to 190*-200* until im back on the throttle again..
its deffinitly got the power to pull the hills....it just heats up quickly

 

[FordGuy100]

Yeah, sounds like something isnt working right IMO. What kind of thermostat does it have in it?

The key is high rpm's from what I found, run it against the govenor and let that fan do its job

 

[towcat]

you hearing the fan kick in?
there's no mistake when the fan kicks in, there's a B17 under the hood and your temps should drop like a rock.
If you're pulling regular, time to check out a MS tech modded fan clutch.
Electrics can't come near the CFM's of a clutch fan when it engages.

 

[freebird01]

it may have an ms tech modded clutch but im not sure. the guy i got the truck off of said it has a "special fan clutch" but i dont know how to verify that...

the fan is working though...it spins all the time...even at idle...i got no idea what t-stat is in it...i may just change it just for peace of mind....any recomendations???

i was thinking on puttin the electric fans in there just to supplement the stock fan....not as a replacement

 

[sle2115]

Yeah, sounds like something isnt working right IMO. What kind of thermostat does it have in it?

The key is high rpm's from what I found, run it against the govenor and let that fan do its job

Sounds counter productive to me! Yeah, your turning the fan faster, but your also lighting the fire in each cylinder twice as often or more!

 

[sle2115]

it may have an ms tech modded clutch but im not sure. the guy i got the truck off of said it has a "special fan clutch" but i dont know how to verify that...

the fan is working though...it spins all the time...even at idle...i got no idea what t-stat is in it...i may just change it just for peace of mind....any recomendations???

i was thinking on puttin the electric fans in there just to supplement the stock fan....not as a replacement

Most on here will say Motorcraft only on the thermostat. I am running a Stant, have ever since I bought my truck with good results. My truck, like yours sees a temp climb pulling grades, although mine is not so severe. I usually start checking things if my truck hits 210, it's not that 210 will hurt anything, it's just out of the ordinary. You may also want to think about a water pump. Sounds to me like a circulation issue as much as anything. If the radiator is new (and I mean new, not different) then I would start looking elsewhere. I don't care much for the clutch fan system on these trucks and others have proven you can keep them cool with electric. The other plus is an electric can shut off when it isn't needed, like 60 MPH while mechanical fan is still turning. If the clutch is unlocked, then it shouldn't be pulling a ton of power to turn it, but it will still take some. Not to mention, you are talking about pushers, not in place of, that should REALLY cool things off!

It's funny though with the digital temp gauge, I can pretty much tell you exactly where my EGT's are by watching it. There is a VERY direct relationship to the two! So I would also have to ask, is the fuel turned up? Is there black smoke during these higher than usual heat cycles?

 

[FordGuy100]

Sounds counter productive to me! Yeah, your turning the fan faster, but your also lighting the fire in each cylinder twice as often or more!

You would think, but thats how it worked for me. I would pull a grade in 4th gear, and loose speed to around 50mph (granted it took a long time to loose the speed, and it would hold 50mph). EGT's where around 1100*, boost 8psi. I would downshift into 3rd, speed would in a matter of a couple seconds be back up to 55mph, EGT's would go down to around 1050*, 7psi of boost. Ran it against the govenor and the water temp would drop around 10-15*. Also keep in mind my truck runs abnormally low on temp, I didnt see over 200* during all of that.

 

[sle2115]

You would think, but thats how it worked for me. I would pull a grade in 4th gear, and loose speed to around 50mph (granted it took a long time to loose the speed, and it would hold 50mph). EGT's where around 1100*, boost 8psi. I would downshift into 3rd, speed would in a matter of a couple seconds be back up to 55mph, EGT's would go down to around 1050*, 7psi of boost. Ran it against the govenor and the water temp would drop around 10-15*. Also keep in mind my truck runs abnormally low on temp, I didnt see over 200* during all of that.

I wonder if the EGT flucuation was from fuel burning in the exhaust? Might be that the actual cylinder temp wasn't changing, but all that unburnt fuel was heating the exhaust. At any rate, I guess whatever works!

Mine is the exact opposite, I don't see an increase so much lugging it, I really see it when I drop a gear and stand on it. My sensors are right in the downpipes though, just off the end of each manifold, I'm NA too, which prolly makes a difference as in your case, the more RPM's, the more air your shoving into the engine. I can see the temp in both sides as well with the dual sweep EGT gauge I have.

 

[RLDSL]

it may have an ms tech modded clutch but im not sure. the guy i got the truck off of said it has a "special fan clutch" but i dont know how to verify that...

the fan is working though...it spins all the time...even at idle...i got no idea what t-stat is in it...i may just change it just for peace of mind....any recomendations???

i was thinking on puttin the electric fans in there just to supplement the stock fan....not as a replacement

You might want to contact MS tech and see if they have any markings on their modded fan clutches that you could identify. It doesn't sound like you have one, it sounds like a worn out stocker. the PO might have thought that a Hayden heavy duty was "special" From my conversation with the guy at MS, the stock fan clutches do not even fully engage until the temp reaches 260 deg. Something ford did to squeeze by an emissions spec., pretty nuts when you consider the overtemp light is set to trigger at 240

 

[Devilish]

You fan clutch could be worn, radiator dirty, thermostat lazy(unlikely), cylinder walls issue(cavitation), timing retarded, or fuel mixture too rich.
Timing and fan clutch are what I'd look into first

You might want to contact MS tech and see if they have any markings on their modded fan clutches that you could identify. It doesn't sound like you have one, it sounds like a worn out stocker. the PO might have thought that a Hayden heavy duty was "special" From my conversation with the guy at MS, the stock fan clutches do not even fully engage until the temp reaches 260 deg. Something ford did to squeeze by an emissions spec., pretty nuts when you consider the overtemp light is set to trigger at 240

I discovered that I had a bad fan clutch the hard way by pulling a mercedes on a car dolly from Vegas in July. I fell asleep for a while till my buddy pulled over with the truck so hot it sounded like little explosions under the hood. Got the truck home but oil pressure goes to near zero when the truck gets good n warm. And that's after a L.O.F! Oh, and my timing was retarded.

 

[freebird01]

the radiator is new and not differnet lol... the fan clutch was new also...both less then 20,000 miles ago (not that it really means anything if its just a rebuilt unit)

the truck really doesnt smoke hardly at all...ill get a puff once in awhile if i lazy shift it while runnin through the gears....or sometimes when i stand on it....but other times when i stand on it it wont smoke...

i changed the fuel filter about 15,000 ago (probably due for that again) ...

i was told the fuel was turned up a bit...but how much i dont know. i was told it was worked on exculsivly by diesel services in reading,PA but there again...i got no documentation to back up these claims.

dont know how old the water pump is or what the timing is....not sure how to even check on a diesel..

anyone got a link for MS tech? i couldnt find their website when i looked..

 

[typ4]

freebird your temps are exactly like mine, your clutch isnt coming on, I jammed mine once with a little bracket and as calvin said you know when the fan is full on., temps stayed down and that, I am in the process of modding my fan clutch as we speak, trying to figure how to tig a blob on the fins to hold the spring.


sle2115 do you have anumber for that stant stat.???

 

[freebird01]

wonder if it would work better to somehow take the fan off the clutch and make a solid adapter so its on full all the time