2003 conv. van 5.2 overheating while towing

[kkja]

I have a 2003 conversion van with a 5.2 that we use to tow our 21' travel trailer. The trailer is well within the tow rating of this 1/2 ton van. On the highway the temperature climbs to the 250 degree range with the A/C on. With the A/C off it will settle around 220. I would love for it to stay in the 210 degree range with the A/C. I should also mention that we tow with OD off.
It is equipped with the factory tranny cooler that is sandwiched between the condensor and the radiator.

Any ideas?
Larger radiator, water wetter, high flow thermostat, etc.

Thanks,
Jeff

[B-300]

I would suggest the use of a 26" wide radiator if not equipped, the smaller is 22" across the core, for older vans.
Also I you could relocate the transmission cooler it would help with air flow thru the radiator.
Make sure the trailer brakes don't drag, inflate your tires and changing to synthetic rear axle oil will all help.

[kkja]

I haven't looked to see what radiator it has.
The tranny cooler is nearly as wide as the radiator so I probably can't relocate it.
Trailer brakes barely stop when applied so I doubt that they are dragging.
Tires are inflated properly and using full synthetic in the engine, tranny (ATF+4), and the rear end.

A guy here at worked suggested a 4 row radiator. I may look into that...
Do the vans use the same radiators as the trucks or will I be looking for a "special" (expensive) radiator?

[Dodgevanman]

Advance Auto has a HD cooling rad. for around $240. It's a 2-row just like the other available, but it has more cooling fins in the core.

I didn't see a 4-row listed, but that doesn't mean one isn't available.

[B-300]

I installed a 3 row radiator on my '71 van a few years ago. At the time it was listed as 2" thick, and there was a 4 row dessert buster that was 2-3/16" thick. This means the tubes are narrower and more fragile, so I went 3 row.
I didn't now the factory trans cooler was that large. (wide)
I'm not so familiar with the newer vans so I don't know if a truck radiator would work... From what I have seen posted the newer trucks ~94 up use a crossflow radiator.
It's possible your cat con is clogging and causing extra heat... Give it a couple of taps when cold, if it sounds like marbles inside, it's toast.

[alloro]

This really shouldn't be happening to a van with the factory tranny cooler. Vans with the factory cooler were assumed to be towing one day and were designed to do so. I would suggest a good flushing of the engine, a new t-stat and a good inspection of the radiator. If the radiator looks questionable, replace it.

[kkja]

Update:
I've contacted a radiator shop and they only list the radiator that I currently have in my van (2 row). No heavy duty option.

I'm waiting for a reply from another shop that specializes in custom radiators.

Another tidbit of information. The temperatures were only high (250) at interstate speeds. When driving 50mph the temperatures dropped to a more manageable level 210-220. this makes me think that the tranny cooler is pre-heating the radiator and the radiator isn't large enough to handle the heat load.

[bheyt]

Just a check.
Be sure you have the over drive off while towing.

[kkja]

Yes, I tow with OD off.

[B-300]

I read in a post somewere that models about 2000 up have transmisson coolers regardless if they have a tow package... steve knows more about the late models and this.
I would consider replacing the transmission cooler with one that can be remote mounted, that has a fan on it if you can't find a larger radiator.

[Dodgevanman]

Advance Auto Parts shows a HD radiator. It's still a 2-row, but it contains more coolant passages than a standard 2-row.

I had a custom radiator built for an A-100 van I had a few years ago. It was a 2-row, but had the cooling capacity of a 4-row.

[stev]

I read in a post somewere that models about 2000 up have transmisson coolers regardless if they have a tow package... steve knows more about the late models and this.
I would consider replacing the transmission cooler with one that can be remote mounted, that has a fan on it if you can't find a larger radiator.

Yes, starting around the 2000 model year and newer, the tranny cooler became standard equipment. :)

I've towed a great deal with both my 2000 B1500 SWB V6 and the B2500 LWB V8 HD suspension. I've never got the temp gage past 220 except once on a 99 degree day towing up the Pocono Mountains.

Rather than looking around for a multi-pass radiator, have you looked into why the tranny has so much heat? Is the tranny filter and screen clean? Are you running ATF+3 with LubeGard? For much of the Dodge Trucks and Vans, the ATF+3 and LubeGard are a must for towing. It's talked about a good deal in the RV'ing forums.

If the van is overheating that much, a 180 degree t-stat would help too. BUT, make sure you don't go below a 180 t-stat since the PCM would get all messed up with it's look up tables. Then the tranny would be doing weird things so I'm told in the Truck section of the forums here.

Water-Wetter is good at the track since it works best under high temps and short day racing. Plus, the mixture in racing is 10 or 20 percent coolant to water. Using it for a long duration will not help as it's properties are used up quickly in time.

You can try to mix the coolant 60 percent distilled water and 40 percent coolant. Never ever use tap water in a vehicle's cooling system.

[DANVAN]

I replaced my factory 2 row radiator with a 3 row rad and it solved my problem. My van never ran hot when it was newer, but after about 10 years or so it started to. I tried flushing with the garden hose kit and several of the part store cleaners, it never helped. I was told by a radiator shop that all dodge radiators clog up after 7-8 years and replacing it would be the only option. The larger 3 row radiator did fix it. The lower temp 180 stat did not help. I also replace a worn out radiator clutch fan which help the overheating in traffic problem which only happened on 1 trip.
I have an aftermarket temp gauge with numbers, so I know my actual temp, I run at 210-220 with out the camper with or with out the ac, and about 230 with the camper with or w/o ac. Ill shut ac when climbing big hills. But it still doesnt get hot even when climbing any more.
I also upgraded my aftermarket trans cooler from a 5000lb rated cooler to a 10,000 rated cooler befor the larger rad, that didnt help, it all came down to the radiator. Go with the 3 row rad.
Good luck.

[bobo35]

When is the last time the water Pump was changed? had to do mine a few years ago on my 94 B350.

SW