Was our Dodge Ram tuner really necessary?

​Our 42-foot fifth wheel, Tagalong, provides everything we need to live: a living room, kitchen, dining table, bedroom, bathroom, office space for me to work, and plenty of storage. Without a truck equipped to tow it, however, it’s immobile, even though it sits on four tires. 

When our Dodge Ram 3500 dually, Gulliver, started making whistling noises while towing Tagalong up a mountain in Montana, we didn’t like what we heard. We found the incessant, high-pitched sounds annoying and disturbing. Clearly something wasn’t right. 

We recently picked up Gulliver from Copperhead Diesel Performance in Chandler, Arizona, after 2.5 weeks of his absence. (To be fair, the 2.5 weeks included Thanksgiving weekend, when the shop was closed so that the employees could enjoy time with their families.)

Since the $8,000-plus repairs, Gulliver sounds much different than he did when we took him in — and even than he did when leaving the Phoenix area last year. It seems that’s when our issues with the truck really began, on a climb to Flagstaff, Arizona, at the start of our 2025 travels. 

We thought adding a tuner to Gulliver would fix the problem — and it seemed to — but now we’re not so sure. Here’s why.

Exhaust leak

When the shrill whistling continued to be apparent in the cab of the truck, seemingly located on the passenger side, we figured we were dealing with some sort of leak. As it turns out, Gulliver had a cracked exhaust manifold, a common issue in Dodge Ram trucks. 

A technician replaced the single-compartment part, which is known to shrink and crack over time, with a dual-compartment piece. This should help prevent the possibility of another leak and reduced engine efficiency. Maybe that’s why Gulliver sounds different. 

As part of the project, the technician had to remove the exhaust gas recirculator (EGR) cooler, clean it, and install new gaskets. He also had to take off the turbo and put it back on, which meant a coolant change as well.

Transmission tune

To get to the exhaust manifold required removing the tune we installed on the transmission and draining its fluid. That went off without a hitch. 
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The initial evaluation of the truck this time around revealed a broken transmission control module, so we had that replaced too. But when the technician reapplied our transmission tune after the fix, it broke. It seemed that the manufacturer of the tune sent the wrong code. Could that have been the cause of our original problem?

Proactive repairs

Regardless of the answer, an assessment of Gulliver’s fluids under the hood found a deficit for the power steering pressure hoses, so we had the shop proactively replace the lines and steering fluid. When you’re towing 18,000 pounds, you need all the steerability you can get. 

Since the shop already had the truck and had to take off at least one tire to get to the exhaust manifold, we also had the technicians give Gulliver an alignment to correct his pull to the right. We knew it would save us time from having to take him somewhere else to get that done. 

Back in action

Although we’re not convinced the initial tune to our diesel engine was needed, we trust the guys at Copperhead Diesel and the work they perform. 

Gulliver is better than ever, even if our checking account isn’t. We’re grateful we were able to use a family member’s vehicle while he was in the shop, but we’re more thankful to have him back in excellent working condition. And we’re certain he’s in better shape to tow Tagalong on our 2026 adventures.

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