Fan comes on too often

[bigbobed]

Did my first tow and my only complaint is the radiator fan seems to come on too often. Outside temp was in the high 80's to low 90's. Engine temp guage never got to 210 and the tranny never got above 180. I would expect to see the temp go up 10-20 degrees before the fan comes on. Seems that anytime I put more load on it the fan comes on. Even on the level when I put my foot in it to pass. Didn't see the temp go up before or see it go down after the fan engagement.
Comments welcome.

[SoMnDMAX]

Please don't take this the wrong way, but-

Would you rather have it overheat?

I wouldn't.... smile.gif

[cmadmaxman]

Have only had it come on when I was pulling the trailer. When out west last year 103 deg., it came on a lot. You get use to it after a while. Thing about it is that the temp gauge never wavered. My total weight was over 16k.
Turn up the radio :D

[Lone Eagle]

SoMnDMAX, I just pulled for the first time and the temperature was in the mid 50s. The fan came on several times on the longer hills in 4th gear. The trans temp was 180 and the engine at 200. I think this falls under the category " we don't understand all we know about this fan". This is my 4 Chevy since 89 and it does operate differently than the others. Have the rest of the forum posters noticed this or are there a few fans that need replacing? Later! Lone Eagle :D

[srubrn]

Just made a trip with my 29.5ft. fifth wheel with two slides in mid 80 degree weather. Fan only came on after I slowed down and took a exit. It never came on while at hwy. speed which was 70 to 78mph.

[bigbobed]

SoMnDMAX

No offense and no I don't want it to overheat.
However (got to be a however) since the temp guage is redlined at 260, it seems that the temp could goto 220-230 before the fan kicks in. Also, if the fan is doing anything besides making noise, I would expect to see the temp go down rather quickly with the fan on. This is sort of like the shift busyness that everyone complained about. No deadband. Unfortunately it can't be fixed with a software change.

[TLA]

The temp guage reflects the coolant temp in the engine. The fan senses the temp of the air flowing throught the radiator. If you have the A/C on, and are towing (where the trans cooler and the intercooler are giving up a lot of heat), it will react to that increased heat by kicking in. The temp guage seems to only react on a really long pull with a heavy load.

[01_Duramax_Dually]

The fan is not really to drop engine coolant exclusively but to assist in pulling more air through all the coolers(especially the intercooler for the Turbo). TLA said it!
If you go out and take a look, you have an Oil cooler, Tranny cooler,AC condensor radiator, Air to Air Intercooler for the turbo and if that was not enough...your Radiator... Air to air intercoolers are not extremely efficient, and when towing, they get very hot. When all those coolers get hot the air comes pushing through heating all the subsequent units behind it. The fan comes on to add to the naturally forced air.

Mine comes on regularily when I am towing up grades, I just turn up the tunes, recline the seat, Reeeeeeeeelaaaaaxxxx and tow at 70+... :D

Regards

Jeff

[ 04-24-2002: Message edited by: 01_Duramax_Dually ]</p>

[Kennedy]

Well put Jeff,

If you've suffered through the non existent engagement of a 6.5 fan clutch, a little noise is a welcome thing! Without good airflow, the Dmax intercooler will not function properly. While I believe that the calibration could have been just a bit more gradual, I am glad they erred on the conservative side for once. Previous calibrations took customers noise complaints into consideration, and got us a poor calibration.

[bigbobed]

Thanks for the replys.
Being a new diesel owner, didn't think of the intercooler. My symptoms would match a heat buildup in the intercooler.
My wife aint goin to be happy.

[Kennedy]

Yeah, I know what you mean. I got a lot of "guff" for the launch shudder on our recent tow.

Guesss I gotta get some caster shims and fix it myself cause I KNOW that GM hasn't got a clue...

[Lone Eagle]

Kennedy, Don't buy your shim kit from Bell Tech. They don't have a clue on the proper bolt to send. Later! Lone Eagle

[SoMnDMAX]

BigBobed, I second what TLA and Jeff had to say....