24-valve diesel overheating when towing

[JEssman]

Recently my 1998 Dodge 24-valve Diesel started overheating when towing my 5th-wheel over the mountians. I had the antifreeze changed, but it did not help. I have not had the transmission fliud changed for about 25,000 miles. My next attempt to try to correct the problem is to have the transmission fliud and filter changed. I asked the dealer to change all the fluid in the transmission as well as the torque converter. They said they could not do that without dropping the transmission. Is that correct??



I did have the fuel injectors replaced with high performance ones that boosted the HP by about 30 and rear wheel torque by 100 ft. #.



I have talked with the dealer and they have no idea what is causing it. Any suggestions as to what the problem is and how to solve it would be greatly appreciated.



Joe

 

[Bob Wagner]

sounds like

you need to replace your thermostat.



This is a common problem that is associated with a bad batch of thermostats common with your year truck.



It would cost you an arm an a leg to have the dealer drop your transmission.



Go to a reputable transmission shop in your area for other options.

 

[lizzyhermit]

ditto on the thermostat. my 98. 5 had one of the "faulty" t'stats and once replaced, voila, no high temps. I can't get my Phoenix based truck over the 190 mark towing 30' of TT in 110+ degree summer heat.



btw, we have a 5+ mile 6% "hill" just north of Phoenix and the truck doesn't care what the ambient is, it just pulls the hill. (OD off, A/C on, tunes blaring, dog whining and grinning ear to ear (me, not the dog). I love passin' folks on that hill, specially the yuppies in their SUV's.

 

[Okie-Go]

I agree with the big hill North of Phoenix. I didn't exactly keep score but I think it is as tough or tougher than Wolf Creek in Colorado. Pulled them last summer in a 98 auto. Can't wait to get teh HO 01 on them. My temp got up there but came back down after getting to the top.

 

[SLightfoot]

Like they said!



Yep, change out that thermostat. There was a bad batch of them.

I had one of them too.



Changed mine out 2 months ago.



Takes about 20 minutes to change. Real easy.



Shawn

 

[MidwestMotorman]

EGT check

You are towing with gauges aren't you??? A performace mod of bigger injectors must have an EGT gauge. You could end up boiling your coolant from overfueling. Finding pieces of the piston melted to the combustion chamber would not be fun.



If your EGT is in check, change the thermostat. You might try cleaning the bugs out of your radiator and ac condensor fins at a car wash or use a garden hose.

 

[Turbo Trucker]

I had the same problem with the thermostat. I tow a lot of weight, and it won't go over 190 now.

 

[tobaccogrower]

i had the same problem on my 99.

i put in a new thermostat and no change! come to find out i had a bad fan clutch. the way to check is when the truck is warmed up,open the hood and watch the fan when you shut off the truck. the fan should stop in under 2 turns. if it spins several times, fan clutch is bad if thats the case and you arn't under warantee, get a horton or twin flex-a lite !! after all, a few extra horses always helps..... james...

 

[HDH]

Ditto, Ditto and Ditto.

Jessman

I had the same problem, as Ramhead3437.

My Thermostat work fine for 70k mile, Then the Next time I towed my Trailer, The Temp gauge was at 220f on the Same hill I have pulled before at 190f.

When I pulled over, I noticed that for running at 220, The Fan was'nt running like it should have.

So after the trip, I Replaced the Thermostat, That Helped some, Then I replced the Fan Clutch, That Really Helped!.



So Both the Thermostat and Fanclutch were bad on mine at 70k miles.

My Fan clutch was sqeeking on shutdown. Sure sign its bad.

Doug.

 

[juicedcummins]

overheating 24valve

I had the same problem on my 99. The dealer said it had to be the fan clutch so he changed it. WRONG!! While on a bowtie rescue and retrieval mission from Alamagardo-New MEXICO I could not exceed 55mph!Even though I was at my max load rating this truck should heat-up like it did so I limped it into Lincon Neb and tried to get a t-stat change. They were to busy to do it and they didn't want to sell one over the counter ! IN the end iI got a t-stat and changed it on the steet in less than ten minutes!Now i can run this one for all it will do and it will never heat up!! This trip was over 3300miles in less than 4 days at max gvw both ways! I have since added a Hornton-FAN not for the extra cooling but for cold weather operation and warm-up. Why drive a fan if you don't need to?





1999quad-cab loaded. bd rv-box,bd injectors,bd-boost-fooler,bd-vlvebody,pro-lock converter,horton-fan,custum lift-pump,drilled out bango-bolts,k+n,a-pillar gauges,4inch custom exaust

75000miles 34psi-boost no problems yet!

 

[TowPro]

Re: overheating 24valve

I had this problem back in 99. I put the old thermostat in a pot of water on the stove with a thermometer, put the heat to it, and at 190 it would open, but only 1/2 way.



My problem was overheating (well it would go up to around 210 before I would let off) trying to go over 55 towing 7000 lbs.

Empty I never had a problem.



Had mine mail ordered from Cummins for about 1/2 what the dealer wanted at the time.

 

[HDH]

Towpro,

I had done the same as you inregards to the thermostat test.

My Fan Clutch was also bad, at idle and 210f I could grab fan and hold it.

The fan never did kick in even when the temp was at 215f.

Now with the new fan clutch, The truck runs much cooler (around 180f) and when the engine is under load the fan kicks in and realy stirs up the dust on the ground.

 

[JEssman]

Thanks to all that responded . I will chnge the thermostat, and check the fan clutch. I was about ready to trade the truck in for one that would tow a larger load. I do not plan to now. I like my Cummings. Again, thanks.



Joe

 

[Timinator]

I would be wary of an auto or truck service place that would not recommend a t-stat change/test first. Very cheap and quick compared the other potential problems.

 

[Ron Bissett]

change oil in transmission

Ditto on the thermostat . As for getting out all the fluid with out droping the pan . One way I have done on a 5. 9 Dodge gaser was after changing fluid took return line loose and with help of wife started eng let eng idle fluid pumped out and was dark ,wife poured new fluid slowly into funnel in fill tube as I caught old fluid in clean container when fluid was clear stoped eng ,replaced line . Started eng rechecked fluid top it up to mark . Also checked fluid in container for any sign of contamination or metal as I do with the pan fluid before desposel . Make sure to check for leaks after running the eng one more time after checking fluid in bucket and you can see if you are puting in the same amount of fluid you took out and will know how much it will take next time . Its not a hard job takes only extra ten min. Hope this helps , Ron in Louisville KY I forgot to say do not start eng after changing fluid in pan as the fluid still in converter will mix with new fluid . wait till finished with converter LOL Ron

 

[Roger rodbolt]

JEssman,

Yes me too on the thermostat, I've replaced the orignal on my '98. 5 with a Cummins 'stat, and it went out within a year I installed a Horton fan and it only engages on extreme inclines when towing or when idleing due to a/c pressures. The first generation Rams are very dependant on fan clutches though... .



nathanbush,

Have you experienced increased coolant temps due solely to high egt's? I've drilled out a number of injectors and overfueled a few times but have not noticed a increase in radiator temps. Several on TDR have mentioned that egt's drive coolant temps but my guess is that most of the heat leaves with the exhaust. Definately the pistons heat up and since they are fed oil for cooling and the oil cooler is bathed in antifreeze I suppose would drive temps a little. My experience is that a defective thermostat or really blocked airflow (cardboard or Alaska swarm bugs in radiator front)

or a missing belt will cause temps over 200 degrees. The 2nd Generations CTD use a V10 size radiator which has a nice reserve for us with #2 fueled toys.

 

[JJMiller]

While we're on the subject, I have a question---



The factory fan clutches that we have--how do they work? Obviously they engage and disengage the fan, but what tells the clutch when to engage? Is what type of clutch is it? (I think it feels like some kind of viscous coupler, but I'm not sure). Thanks for any help.



--J

 

[SteveAZ]

I had the same problem w/o towing. Ran a solid 190 from day one, and would climb high enough to set off the check gauges alarm, thus approaching 220 or so temps when romping up longs hills, yes even w/o a tow.



Installed a new thermosat, now runs a solid 180 to 182 empty and climbs and holds at 190 w/ tow on hills.



Compared openings of factory vs. NAPA replacement, the NAPA part has an significantly larger opening, thus less restrictive water flow.



Worked for me!