I have an 01 CTD automatic with no mods (yet). This thing gets up to 238* while towing my 9,000 lb (weighed at scales) trailer (toyhauler) up any measurable incline, and it's not even summer yet. It was 73*'s today when I took it in to the dealer. He hooked up a computer to it while drove it up a local hill. Says the torque converter wasn't locking up soon enough, and there might be a fuel problem...leaned out.


Anyone else have any of these symptoms? I have 86K on this truck.

Forgot to mention....it will max out @ 40/45 mph on a 6% grade (the Grapevine here in sunny So Cal).

 

Have you checked the radiator?Is the fan kicking in at all?

 

Look at this very similar post:
https://www.dieseltruckresource.com/...ad.php?t=99202

 

Does your transmission cooling lines go through the radiator??

I had a 79 Chevy ton with 454 and Turbo 400 automatic that would run the temp-gauge way up towing cattle on a grade.

I plumbed in an auxilliary transmission cooler, seperate from the radiator, and end of problem.

It is amazing how much cooler the truck ran.

This was my first-last-and only automatic truck I have ever owned; I hope I never have to own another.

 

Factory installed tranny cooler. Fan kicks in just fine. Thermostat works too.

Now what?

Bigger issue is not being able to do over 40/45 mph on a measily 6% grade.

 

What is your coolant mix. Start with a coolant flush and refill but try more water than coolant. Use distilled water only. That's good for 20 degrees. Are the fins on the radiator clean. Is it filling the overflow? If not then change the cap. ks

 

This happens everyday for me. Pulling a backhoe. I am twice your weight but exact symptom. super high engine temps but once the hill is passed it cools immediately and I can run up to 70mph on flats.

If I can get to 70+ before the hill then I might be able to hold 60mph going across.
I've brought this up before also. I'm in Texas, we dont really have grades, just an overpass knocks me back to 40mph. My 6spd is totally different.

 

If you guys still have the oil breather bottle up front and operate in any dust thr dirt gets trapped between the radiators and causes a cooling problem. The rads must be pulled and cleaned, I took out the drip bottle and it is exiting down below the front axle. Never trust a stock guage or a comp link install a mechanical temp guage in 1 of the head cooling ports and it will read the actual coolant temp in the head as it is pulling. An automatic should have an external cooler isolated from the coolant rad if towing heavy in high heat on a regular basis, thus allowing transoil and coolant access to outside temps which can be 100F cooler even in 100F+ heat. A/C will also transfer heat back onto the coolant rad as well, the hotter it gets the more heat that needs to be dissipated from up to 4 rads in front of each other. If the truck is an 01 like mine it is possible the coolant tubes are starting to plug up which will also reduce cooling capacity and made need a flush or replacing, a bug screen or grill guard can also hamper the cooling and access of airflow. If the rpm is too low the fan cannot draw sufficient amount of air, pick a speed it likes to pull and lock or select the gear which allows 24-2600 rpm with the fan engaged to draw maximum air flow. In the automatic if the torque is not locking up it will generate extra heat and transfer it back through the trans cooler in the coolant rad as preheated air. CLEAN those RADS. PK

 

Can you help us identify the Oil Breather Bottle? I don't recognize this.I don't run the AC when pulling. But I have been looking at something like a Flex a Lite extra cooler or something like that since I saw it on here.

 

I don't tow anything so I'm more asking that suggesting ...... with a given engine isn't the largest contribution to engine heat the amount of boost being used ? The amount of boost/throttle needed will depend upon the load, grade, altitude, and overall gearing. Looking at rpm vs speed, tire size, tire pressure, etc. these trucks as delivered seem to roughly be set up for towing maximum loads at about 65 mph, so if you're using something like a 3.54 on older truck or a 3.73 on a newer truck, either with bigger tires ,you'll be more likley to need more boost/throttle and run hotter. Autos will make it worse as they seem to use the radiator for cooling, which will reduce cooling capacity.

A friend with a newer 3500 SRW with an auto said that he could do 65 mph pulling an 8k load on the Grapevine, but that was with stock tires and 3.73 gearing. He recently put on a set of Hummer takeoff BFGs, and said that it seems to have cut into his towing capacity a bit.

 

It's the puke bottle getting oil mist on the rad, which causes dirt to stick to it, which causes the overheating. You need to remove, clean, and reinstall your rad. While you're at it, change the thremostat.

YOU HAVE TO READ THIS

 

First- your truck is not leaning out, if it was you would run cooler not hotter like a gasser. You have a problem though because my stock 01 will pull a 10K trailer up a 6% grade with the air on and never go above 210. Follow all the suggestions above.

 

"A friend with a newer 3500 SRW with an auto said that he could do 65 mph pulling an 8k load on the Grapevine, but that was with stock tires and 3.73 gearing. "

Thinking more on the issue, he also said that his truck worked hard pulling a bit bigger trailer on some rural roads, where he didn't have the 'running start' that you can get on the highway. I guess this is why the 4.10 gearing is provided, and why the 6 spd manual is still popular. I've run across more than a few comments that the older trucks with the 3.54 worked pretty hard in hilly areas, and that's why the 'standard' gearing was changed to 3.73. That would suggest that a truck with 3.54, an auto, a big load, twisty road and hills might need smaller tires like 245s, not bigger ones.

 

Thank you!!! I can't believe it took so long for someone to point that out.

Sounds to me like a new mechanic needs to be found if he thinks the diesel "leaning out" is causing HIGHER temps!

1) Clean radiator gunk and relocate puke bottle
2) Install aftermarket/aux tranny cooler
3) Consider aftermarket torque converter, as the loose factory converter is the source of the excessive heat under load.

So these in order, and your heat problems are gone forever.

jh