I have a 97 6.5 dump truck.Truck runs hot when loaded or not and really hot pulling a hill.Hot temp is around 230.The clutch fan does kick in!Around town its around 190 unless you work it.Pmd has been done 2 times in 2 years under warrenty.I flushed rad changed thermostats and the water pump while at it.I also installed a trany temp gauge and a extra trany filter+pyro+boost guage to help trouble shoot.I got the trany temp up to 240 pulling a hill @ 20 deg F with no load on truck.Around town 175 to 210.The egt's I can get to 1300 @ 70 mph with my foot really in it and normal around town 600 to 900.Sensor is installed pre turbo.The truck is stock except for a K/N filter.I know I have to do an exhaust but dont think this is a cure all fix.I have been thinking the IP timing may be off from the PMD change?This is my bread and butter truck so I have to make sure she's happy!!!

97 GMC K3500 6.5 4L80E DUMP

That EGT is getting up there, Exhaust really does make a difference, also need to look into a recalibrated fan clutch, I doubt it's timing related, might be thermostat problem though did they put in new ones of the right temp range when they replaced the IP, aux tranny cooler will help shed some heat, I also like the PML deep tranny pan www.yourcovers.com (http://www.yourcovers.com/) adds 3qts more trans fluid to heat up and finned bottom dissipates some heat.

Know anyone with a GM Tech 2 or equivalent, Snap on MT 2500 will also work so you can pull some run data, what kind of boost are you getting stuck shut WG can elevate temps, worst offender of all is the crushed downpipe just below the turbo, pure junk NVTMTNLION has got some recent phots of his one of the worst I've seen to date . What do the rad & AC fins look like does not take much crud there to restrict airflow/cooling.

I agree. I used my 6.5 suburban to pull a light trailer and it overheated. My first mod is going to be adding 4" exhaust. If you look at the pictures of an aftermarket downpipe next to a factory downpipe, you'll kind of wonder how the engine runs at all. (there's a thread here somewhere that has good pictures of the two next to eachother)

The stock 6.5 works overtime to push exhaust through the mangled factory exhaust.

You can probably find an exhaust system on ebay for around $300. I've seen several posts where guys say they have lowered their egt's by 200 deg. after installing 3 or 4" exhaust.

3.5" is minimum I would go, 3" works for bone stock, once you see how much better these things run once they start to breathe, you WILL start adding do-dads for more power, and then you will be say darn why didn't I put on that bigger exhaust, 3.5 to 4" not much difference for most; you need the rest of the do-dads to realize any benefit, once I go to 18:1; I'll be asking the same question dang why didn't I go to a 4" tube.

Sounds hot! That's the kind of temps people report before repairing the head gaskets. Did you make sure your radiator cap is holding pressure?

I'd try Water-Wetter before spending a bunch of money on upgrades.

Hey Guys thanks for the info - QM's reply.I am aware about what damage the heat problem can cause that is the reason I am posting,and last but not least learn how to spell PEOPLE!!!! Rad is clean and fins are good truck has a oem trans cooler and my bad I forgot to mention I have a deep trany pan.The thermostats are the stock replacements.I would like to know at what points does the truck call for boost and when it drops off.I know that a stock 6.5 does not call for much of boost.My max boost is about 13 to 14 and will even out at about 6 to 7 and then drop off.It seems like it drops off when I need it most.I did replace the pump about a year ago.Thanks again for the help guys!!!!!!

Sorry, when I type fast I transpose letters.

You using WW and have good results I have heard some who say not worth the money and others say that it's great stuff, what are your feelings and did you try it solo or after mods.

Pipes bought, recycled, or homemade are IMO the best/cheapest way to lower temps and step 1 for more power, adding more boost (Make sure vac & WG are functioning properly, good vac use a fooler no vac a TM is way to go), can also lower temps, both of those are good bang for buck mods.

I'd try Water-Wetter before spending a bunch of money on upgrades.

Bigger, free-flowing exhaust with no cat is worth every penny in these rigs. As a side note, with the dual thermostat setup, the thermostats are not the same. I think one open at 190 and the other at 180 or maybe even lower. You didn’t use the same thermostats for both did you?

I have not personally used WW, "YET". My truck is light and has not had overheating issues. I have never heard or read a negative feeedback on WW, from someone who put's it in a GOOD running motor. I have heard that it doesn't fix an already heat damaged motor, go figure.

Having said that my 97 cooling upgrade installation will be finished after a fitting arrives at the dealer this afternoon. I have not had any overheating issues with my current configuration, but my future plans involve getting more power out, so I can run 44" bogger tires.

4" exhaust is sitting in the garage waiting to be installed.

I use Water Wetter in all my dirt bikes. I know it's not a scientific test but on my KTM 300 in 25 degree summer riding through real tight single tracks it use to boil over without WW. After adding it the bike never over heats. If my 2 stroke bike that is push to the limit doesn't overheat then it's not a bad additions to my 6.5.



You using WW and have good results I have heard some who say not worth the money and others say that it's great stuff, what are your feelings and did you try it solo or after mods.

Pipes bought, recycled, or homemade are IMO the best/cheapest way to lower temps and step 1 for more power, adding more boost (Make sure vac & WG are functioning properly, good vac use a fooler no vac a TM is way to go), can also lower temps, both of those are good bang for buck mods.

Also, on my 96 without the dual T-stats. I have yet to see my gauge go much pass 100 degree C. I pull a 24 travel trailer that weights 4500 lbs over the mountains in BC. From all the overheating problems I read here I think water wetter is working for me.

Dave

That is good data/feedback I'll have to a take a closer look myself, IIRC requires you to get all the old coolant purged, or maybe that was a similar product different company, you have any difficulty getting the old purged or does WW mix with green & orange coolant.

BTW 100C = 212F ever use a scan tool to see what actual reading is only time I ever got that high was hauling 18K load and lost a IC hose, 65 to 10mph in zip point nuthin, temps got hot on that pull, never in boil over danger zone used defrost & minimal go pedal to keep heat driven back, it was 105F = 40.5 C that day WW would have come in handy.

Suggestion I hope others will adopt, I'm going to start posting my data in both units imperial & metric, that way it will make more sense to all who drop by, I know when I do business with my non US customers takes a bit between the both of us to comprehend just how hot,hot is a 750 deg jet at idle means nothing to me unless that is in degree C 1382 F is darn near max power temp limit on some of my engines. I don't register mentally in metric I have to convert to get the big picture I suppose it works the other way also for folks that have learned metric 1st. here is a handy link I use to convert http://www.onlineconversion.com/temperature.htm

Cleaning house in front of the radiator would be my first suggestion. My Special Calibration fan clutch would be my next. You should see inprovement in all temps with this clutch.



I have a 97 6.5 dump truck.Truck runs hot when loaded or not and really hot pulling a hill.Hot temp is around 230.The clutch fan does kick in!Around town its around 190 unless you work it.Pmd has been done 2 times in 2 years under warrenty.I flushed rad changed thermostats and the water pump while at it.I also installed a trany temp gauge and a extra trany filter+pyro+boost guage to help trouble shoot.I got the trany temp up to 240 pulling a hill @ 20 deg F with no load on truck.Around town 175 to 210.The egt's I can get to 1300 @ 70 mph with my foot really in it and normal around town 600 to 900.Sensor is installed pre turbo.The truck is stock except for a K/N filter.I know I have to do an exhaust but dont think this is a cure all fix.I have been thinking the IP timing may be off from the PMD change?This is my bread and butter truck so I have to make sure she's happy!!!

97 GMC K3500 6.5 4L80E DUMP

My JK fan clutch probably helped me stay cool the day I blew the IC hose, works so well I forgot to mention it was on there as well. Definately part of the whole cooling solution, pipes or fan clutch hard call for me Kennedy has both, I lean towards pipes as you get some oomph as well as lower temps.

Cleaning house in front of the radiator would be my first suggestion. My Special Calibration fan clutch would be my next. You should see inprovement in all temps with this clutch.
Hey JK, You have a great site and I have purchased from you before.I like the idea of the clutch kicking in sooner.I also noticed a pancake dual electric fan deal on some other sites?I will assume you like the clutch fan more.Let me know your thoughts.I really dont like my trany temp.I plow alot and change filter and fluid before the winter.I also added a external filter kit + deep pan and my probe reads off the line feeding the cooler.I did some big commercial jobs this year and one time was out for 22 hours non stop so today just to try something I replace the fliud with amalie dexron-mercon v thinking it maybe I cooked the old fluid a bit.It ran about 10 deg cooler on my hill climb test from the other day.Let me know your thoughts.
Thanks

Sean

Sean, your probe temp on cooler, that on the factory cooler, I added a second cooler rated to handle 25K#/11.33MT load with electric fan under my bed, controlled by a thermo switch set to come on at 170F/76.6C I rarely break 180F/82.2C trans temp when towing even as much as 18K #/8.16MT trailer.

The next time you see these high temps. pull over and try to get some kind of feel for the temps all along the radiator. Just because you got it flushed out doesn't mean it's flowing to 100%. These also tend to catch alot of junk between the coors. You will have to remove the other coolers in the front to really clean them out.

A few have claimed to do OK with electrics, but think about how many CFM that monster engine driven fan can pull,and how much juice a comparable electric would need. Then think about how robust:rolleyes: the GM alternators are when worked hard...

Ha,aaaaaaaaaaaa What up!!

Glad your finally here! Hope you weren't trying to stay in incognito :D
That 01 in the driveway yet? Lemme know when you want a Juice box for testing!

These guys will help you get that 6.5 diagnosed in the mean time good luck Sean catch up soon,I'll buy the suds ;)