Best Solution for Lowering Vehicle Temperatures When Towing

Question:

Dear etrailer.com Experts, I have a 2003 GMC Yukon XL 1500 5.3 150,000 miles. All stock with a OEM towing package. I have been to towing my boat short distances for the past 7 years and have no issues. However I recently purchased a a very light weight travel trailer under 2000 lbs its a 2015 Shasta Airflyte 16. The problem I have is when towing up hill long grades. My Yukon normally runs at approx 200 degrees according to my stock gauge. However when towing up long grades, my temp raises to 220 to 230. If I back off on my speed and turn off the AC the temperature drops. Although I think this my be somewhat normal, I am concerned with this and afraid that this could ultimately cause harm to my engine. I am trying to get your advise if you think one of your electric fans could eliminate this behavior and if so which fan would you recommend? Thanks in advance.

asked by: BOB C

Expert Reply:

The added stress from trailer towing usually shows up as an increased transmission temperature. I am not sure if the gauge you're referring to is displaying engine coolant temperature or if you have one that shows transmission temperature.

We do offer Derale Class III transmission cooler # D12903 for your 5.3L Yukon XL which measures a generous 15-1/4 x 7-1/2. This can be mounted in front of your AC condenser to provide supplemental transmission cooling after the OEM cooler in the radiator does the initial cooling. If you have a 5/8 hex on your transmission line you'll also need adapter kit # D13018.

Any vehicle that tows will need shorter service intervals for its fluids, both coolant and transmission fluid. Your owner's manual may have recommendations. If your coolant has not been changed in the last 2 years you might consider this step; you can then see if new coolant helps reduce the temperature rise when you tow. The same applies to the transmission and the addition of a transmission cooler will make a big difference for towing-related heat. If you install a supplemental trans cooler and also have your transmission fluid changed you should see a worthwhile and noticeable drop in transmission temperature.

Another option is to install a combination transmission and engine oil cooler that cools both fluids, such as the Derale # D13302 which measures 16-13/16 x 12-5/8 x 3/4-inches. If you can fit this in front of your AC condenser you can cool both oil and transmission fluid in one unit and take a lot of stress off the vehicle.

Add-on electric fans help in terms of increasing air flow when towing at low speeds on uphill grades but additional coolers will really drop the temps better.