I have a 99 2500 Dodge Quad Cab, long bed, 4x4 and tow a 30' fiver (about 9K loaded). I can not run AC and tow at the same time, the truck will also overheat on hot days. Everyone that I have talked to tells me that I should not have any problems, but they can't tell me why I am either. I have 3.54 gears and I am wondering if changing to 3.73 or 4.10 will make a difference. I have had the motor and trans dyno tested and both checked out fine. Does anyone have any suggestions, short of buying a new truck?<br><br>Molly

 

Welcome to the forum mbw. I would make sure that your radiator, tranny cooler and intercooler are clean, especially in between them. You may have to take a water hose and blast out the dirt and bugs, just be careful and dont mash the fins. I would also check your thermostat. Somebody will jump in here and correct me if I am wrong. I think the thermo is designed to fail in the open position but it could be partly closed. A good flush of the system could help also. Check the hose connections to the turbo and the turbo bolts themselves make sure everything has a good seal. Air filter would be another place to look. Just throwing out some things to look at.<br>

 

I should have clarified that I am having problems with lack of power, along with the overheating. It seems like the truck is really working hard to tow what I have. We did not tow with it when it was brand new, only started towing last year or so. I don't expect a race car performance, but I expect the diesel to do what it was designed to. That's why I had the motor and trans dyno tested. My only option left is changing gears or buying a new truck....

 

every think of maybe a horton fan clutch, lower degree t-stat.<br>also check for dirt in front of coolers and rad. in terms of differant gears your fuel milage will suffer maybe some 275 injectors,bhaf and a aftermarket exhaust. add a chip to here, many options instead of gear changes. good luck, jr

 

THE EARLY 1999 MODEL 3500 CAME WITH THE WRONG <br>THERMOSTAT. VERY EASY TO CHANGE OUT...TWO BOLTS,<br>POP OUT OLD ONE AND REPLACE WITH CORRECT ONE.<br>VERY LITTLE LOSS OF COOLANT. O RING IS USED A GASKET.<br>MINE HAD LOW POWER AND THEY REFLASHED THE COMMUTER<br>FOR HIGHER POWER. THE LAST NUMBERS OF AVAILABLE<br>FLASH IS A 05, OR THEY CAN DO A HIGHER OF 06.<br>THEY SOLD THE TRUCK WITH LOW POWER TO SAVE THE <br>TRANSMISSION, AVOIDING WARRANTY WORK UNTIL YOUR <br>WARRANTY EXPIRED UNLESS YOU COMPLAIN. IF YOU DON'T<br>THE HAVE ADDED STICKERS ON THE FRAMEWORK FORWARD <br>OF THE RADIATOR IT HAVEN'T BEEN DONE. REQUIRED BY<br>LAW TO POST THE STICKERS OF CHANGES MADES BY DEALER<br>TO ENGINE. WAYNE

 

check for a bad head gasket

 

I had the ECM flashed a year ago, when I had the motor dyno tested. <br><br>I will try the thermostat, and check the clutch fan.

 

Don't know if 99's have a blow-by bottle but if you do, might also check that. Leastways on a 2001 it can cause the back side of the radiator to get awfully ugly. Lots of overheating problems cause by that where most people don't think to look. You definitely have something going on.

 

I would also check the back of the radiator for blowby buildup. I moved my vent for that very reason. And I hear diesels are really hard on coolant. Something like it causes the silicant or something to lay and collect at the bottom of the radiator stopping cooling. Someone correct me if that is wrong. If you have an Auto check and see if your torque convertor is locking. They will heat up a motor on a good pull if aren't locked.

 

Are your air hose fittings tight? low boost= high heat, inadequate fueling, low power. I just put a Comp on a friends 99 that had a lack of power, he's grinning now ;D

Imho, a gear ratio won't change operating temp significantly.

 

Don't forget to check the &quot;little things&quot; like the radiator cap, serpentine belt, or idler pully.

If you haven't changed your transmission fluid lately, change the fluid &amp; filter and check the pan for clutch material. If there is material in there, get out your BIG charge card. Check out ATS Diesel's TripleLok converter .. or your favorite tranny shop. Otherwise, adjust the bands and close it back up. Synthetic ATF (i.e. Amsoil) will reduce tranny temps.

Review all the TSB's relevant to your truck. You Might find something helpful there. Good Luck!