# 01-03 2500HD NEW overheat info please read



## SnowMatt13 (Jan 8, 2003)

Recently I posted this issue. There was good response. I suggested people call my Chevy dlr. and talk to the service dept because as it turns out other dealers couldn't help. Well, to say the least there has been a big response. So big, my service manager has asked for people to stop calling for info. SORRY. He said any dealer in the country has the same info as him, and should be able to help you. He said that there is/are TSB's (techinal service bullitens covering this. I would also like to give the new part # for the new fan clutch that should be put into the vehicle.... GM part #22149894. Sorry for the trouble, but he was recieving so many calls that it was hurting his ability to do his job. My last piece of advice is if you go to your dealer with this info and they still can't help call the cust. assistance center 800# listed in the back of your owners manual. Thank you for your understanding. I still can't believe that there were this many dealers out there that were unwilling to help their customers.


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## Barkleymut (Jan 10, 2000)

It isn't that they were unwilling to help their customers. They are just like 95% of American workers. To darn lazy. They probably received the info at other dealers and put it under a bunch of other info that they deemed worthless. Until their boss jumps down their throat don't expect them to do anything. Consider yourself lucky that you have a knowledgable service guy.


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## T. Matthews (Feb 5, 2003)

Hey there,

Couls you fill me in on this over heating problem, I just bought a 01 2500 hd and a friend of mine just bought a 02 2500hd

Thanks t.matthews


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## SnowMatt13 (Jan 8, 2003)

basically in a nutshell, some 01-03 2500HD's will overheat while driving with the plow on them. My personal case was driving between plowing jobs. It happened 3 times in one day. first trans temp guage started rising, then engine temp, the the "check coolant temp" message came on. My dealership installed a new fan clutch this past spring and so far this winter the truck has not overheated. I see guys with HD's driving with plow straight and all the way up, going 55+mph. Maybe they don't have a problem with their fan clutch or maybe theirs is already fixed. After they fixed mine I got into a habit of driving with the plow angled one way or the other and try to keep it as low as possible to get as much air as I can to the radiator. like western recommends.....45mph or under.


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## Shaper (Jan 9, 2003)

Are any or all of these trucks that are overheating equipped with the snow plow prep package?


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## SnowMatt13 (Jan 8, 2003)

I can't speak for everyone else, but mine has plow prep. I can only immagine what a un-friendly dealer would say if you came in with an overheating concern without plow prep


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## archer2 (Feb 17, 2003)

*overheating*

My '02 2500HD has the bad fan clutch. I've been waiting one month for the part. I have found keeping the plow straight and raising it to just below the plow lights keeps the engine and trans. the coolest. Running the heater fan on high while going up long hills also seems to help.


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## rsrour (Feb 18, 2003)

*allison tranny/overheat,tcm probs*

Just adding some more misfortune... I noticed a hi temp after plowing for 4-5hrs. trans was shifting w/big clunks. Indicator stopped showing gear selected. Now indicator just flashes on "3" no matter what gear its in. I let the thing cool and it seemed all right but then it started started shifting arbitrarily. It will not engage any gear some times and sometimes it starts and stays in 3rd. lots of clunking.... I guess I'll go to the dealer. I've got 34.8K mi.


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## BigRedBarn (Jan 4, 2003)

I have an '03 2500HD, so I've been reading this topic with interest (especially since my previous '92 GMC had overheating problems, too).

Dumb question: is there anything available to add to a plow to direct airflow toward the grill/air intakes? I assume not, but it would seem like a good add-on for Western, Meyer, Boss, etc. to think about, of an aftermarket company. 

It would be hard to do, probably, what with all the various truck brands, yearly designs, etc. to deal with. But, there must be something you could put on the top of a plow to direct air toward the grill. It'd have to be fairly short, maybe 2 inches tall, tops. I envision something that is curved, like a plow blade, but with slots in the back. It'd probably get snow jammed in it after just one driveway. Is this a dumb idea?

Or, may slots in the back part of the truck's hood might help airflow. They do this on some cars to get better airplow through the engine bay. But, with a truck being higher than a car, maybe that's not needed as the air can flow downward when it leaves the radiator and engine bay. Or, to get really out in left field, how about auxiliary cooling fans near the rear of the engine bay blowing air downward? This could help airflow though the engine bay but with leaving the OE fan alone.

I also know the problems I have when driving during a heavy snowfall. The air hits the plow blade, shots straight up, where the plow lights hit it which makes it hard to see where you're going.

Overall, it just seems like there's got to be a better way to add a plow to a truck without creating so many problems.


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## rsrour (Feb 18, 2003)

Actually I don't think I really have a tranny overheat prob. if the tranny was working properly. I think what happened first was that I was starting up in drive but the trans was in 3rd-I had a blinking 3 showing on the dash. I pushed this way for a while which is what heated up the trans. Now I am looking for a quick fix for the TCM- When I looked under the truck on the side of the road, I noticed a block of ice around TCM which I knocked off. Did that take it out? or was it low voltage. I will try a hard reboot.


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## archer2 (Feb 17, 2003)

*Overheating*

Adding a snow deflector seemed to help the airflow with my Meyer C-8. I don't know if it helps the cooling but at 40 to 50 mph the buffeting is reduced. I bungi it down because at 30mph it starts to flap. The dealer also says alot of the cooling comes from underneath. That's when I raised the plow about 4 inches and turned it straight to travel. IF I do this with our F350 with 460cu. engine it will get hot quicky. With our 2500HD it seems to help. I got the new fan part yesterday.


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## plowboss (Oct 29, 2002)

hey all, man am i glad i read this, had my 01 chevy hd to dealer already for this problem in december, (it did not over heat all last winter) at that time, they put a new thermostat in and gave it back to me, it made no difference. i,ve been using truck all winter cause i need it everyday here in ne ohio. the routine is get in and start from cold, run about 8-10 minutes, notice temp go up to about 230 or so, pull over and let idle for about 2-3 minutes, goes back down to normal, use truck for 8 hours with no problem, next time i start from cold, same drill, don't expect that from a 2 yr old truck with 18000 miles, hell if the motor blows they can replace that. don,t care, need an extended cab anyway so in april this ones gone. plowboss


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## rec067 (Oct 17, 2002)

rssour,
Your describing what sounds like the NSBU switch. I have heard of these going bad on a regular basis. GM has had to replace several with the updated version (rubber boot) but salt and moisture still effect it. The flashing gear indicator shopuld be the tell tale sign. The tcm is piggy backed on the ecm. Both are located on the driverside of the truck in the engine compartment below the battery (at least on my duramax) The NSBU is on the drivers side of the allision. Hope this helps.

PS what is a hard reboot


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## rsrour (Feb 18, 2003)

The dealer said the thing that went wrong is called it a prindle switch. And what he described was the thing on the driver's side transmission that the shift cable hooks to. When I got underneath to look for problem this thing was caked in asolid block of ice... A hard reboot is to disconnect batteries and reconnect.


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## silveradoatv (Dec 19, 2003)

*2500 HD overheating*

This clutch fan - is this to cool the tranny or the radiator? My 02' 2500hd seems to overheat when I drive longer distances between accounts. The radiator temp goes up as does the tranny guage and I have the snow plow prep package. Any suggestions to keep the temps down (i have tried all the various angles of the blade - straight and low seem to be the best when traveling distance). Do I need to replace this original clutch fan? Any advice is welcome. Thanks.


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## PROCUTSLAWNCARE (Oct 18, 2003)

Just bought a 2004 2500HD Plow preped and got a meyers 7 1/2 on it. I was traveling from job to job and i was on the highway, 70 MPH no problem! I could put the plow all the way up and straight! No problem at all! I bought the truck brand new and drove it home on the highway. It was a 25 mile trip, and it was 80 degrees that day! Never went past 195!!! Oh wait thats cause its a GMC! The chevy's have that UGLY front end, thats prolly why!!! LOL......  

P.S. The plow is a 4 spring polly comercial blade, its tall too and still had no prob!!!????

I dunno maybe im just a lucky one???

Can you take that dumb clutch fan off and put a regular 6 blade solid fan????????


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## SnowMatt13 (Jan 8, 2003)

When I origionally wrote this the '04 model year truck was not out yet. About more air flow, I saw a few trucks locally with a 12"x12" piece of flexi-glass plastic bolted to the lift arm. There were approx. four 1" holes cut inot it to let some air through. Also I'm not sure, but Chevy might have changed the clutch fan in the '04 models. I could try and get the info but I don't work for the chevy dealer anymore, moved on to a municipality (bigger and better plow trucks to play with)


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## silveradoatv (Dec 19, 2003)

SnowMatt13 - my dealer can't find the TSB you are talking about and i am having the same over heating problem. Any chance your dealer could help a lot of us out with the TSB date and number? We would be very grateful!
Thanks.


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## BigRedBarn (Jan 4, 2003)

It would be really nice to know when the new fan clutch went into new trucks (i.e., what build month).

It'd also be nice to know how to tell your dealer's service department that you don't want to be jerked around and that you don't want to have to keep taking your truck in for service to get the overheating problem fixed (I see red ever time I read this on a service write-up: "no fault found, unable to duplicate customer's problem"). It's like the service department thinks I have nothing better to do than get my jollies by wasting their time (and my time) by repeatedly taking my truck in for service. I'm sorry to rant here, but getting jerked around by GM service departments has happened too, too many times in the 25 years I've been buying new GM cars and trucks. 

Finally, does this overheat problem apply to all engines (i.e., do all GM's use the same cooling-fan clutch regardless of engine size)? 



I know that when I drive around town on warm days (40-50 degrees F) with the plow on that after a few minutes I can really hear the engine fan growl, especially on downshifts. I assume that it's seeing some serious heat and that the clutch is locking up good to produce such a growl. I only hope I have the newer/better clutch on my '03 truck's cooling fan. But, probably not, knowing my luck.


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## sbrennan007 (Jul 27, 2003)

I have the same issue with my truck, although if I keep the plow low and strait the temps stay down where they should be.

When I picked up the plow in late summer, it was HOT by the time I got home. The "coolant temp" warning message came on when I got home, so I let it cool down a bit first with the hood open before I shut it off.


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## TLS (Jan 31, 2000)

The reason for the tranny getting hot at the same time is simple. Automatic trannys plumb through the side tank of the radiator and also through a stand alone cooler. If the engine coolant is hot (plow deflecting and preventing highway air from entering), it will actually heat up the tranny fluid as it passes through the hot radiator tank. 

Tranny's usually run at about 140 degrees when they're locked up. Its when the torque converter unlocks that heat is made. So at highway speeds with a plow on, torque converter is locked, tranny is running cool......fluid flows out and up to the radiator tank, gets heated to 240 some degrees or more, then out and up front to a small stand alone cooler which is ......get this.....not getting any cool air!.....So it returns back to the tranny some 100 degrees hotter than when it left!

Now repeat this....and you can see the problem.


The cooling fan clutch is getting fooled because there isn't much "airflow" going THROUGH the grill to activate the bi-metalic spring on the front of the clutch fan. OR.....if it DOES, its too late or the RPM's are too high for normal operation (clutch fans de-clutch at high RPM's) 

The improved clutch fan either locks up SOONER or stays locked until a higher RPM.


To those who want to use an "ALWAYS ON" coolant fan....Just understand that those type don't draw anywhere near the cfm of the clutch type fans capacity.


The hot setup would be an electric actuated clutch fan. Much like the electric clutches found on commercial lawn mowers.


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## silveradoatv (Dec 19, 2003)

I brought my '02 2500HD to the dealer last week and reported the overheating problem. Sure enough, they did know about a technical service bulletin that was issued a while back, but they couldn't locate it. Anyway, they diagnosed the problem as "found fan clutch inop/doesn't turn. Material failure." So, they replaced the fan clutch assembly (j3390) which is part number 22149894, under warrantly and told me I shouldn't have the problem any more. I guess I won't know until it snows again. Anyway, I hope this helps all that are experiencing the same problem.


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## flykelley (Dec 29, 2003)

> _Originally posted by BigRedBarn _
> *It would be really nice to know when the new fan clutch went into new trucks (i.e., what build month).
> 
> It'd also be nice to know how to tell your dealer's service department that you don't want to be jerked around and that you don't want to have to keep taking your truck in for service to get the overheating problem fixed (I see red ever time I read this on a service write-up: "no fault found, unable to duplicate customer's problem"). It's like the service department thinks I have nothing better to do than get my jollies by wasting their time (and my time) by repeatedly taking my truck in for service. I'm sorry to rant here, but getting jerked around by GM service departments has happened too, too many times in the 25 years I've been buying new GM cars and trucks.
> ...


Big red barn
GM will know the vin number for a new fan,I work at GM truck assy in Pontaic Mi in the quality dept. Anytime we have aproblem with a part or a change they get a break point number. They may have to look a little but there is a number for the dealers.

Regards Mike payup


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## BigRedBarn (Jan 4, 2003)

> _Originally posted by flykelley _
> *Big red barn
> GM will know the vin number for a new fan,I work at GM truck assy in Pontaic Mi in the quality dept. Anytime we have aproblem with a part or a change they get a break point number. They may have to look a little but there is a number for the dealers.
> 
> Regards Mike payup *


Wow, great response. Thanks for taking the time to respond.

I hope you didn't think I was coming down on your assembly plant. My only concern is with some of the various Chevy (and Pontiac) dealers' service departments. I could write a book about my trials and tribulations with these various buffoons!!!

I've owned only purchased-new GM's for the past 25 years since I got out of college. I'll likely be a loyal GM owner until the day I die. If I go over to Ford or Dodge, it'll be because of the dealer service departments.


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