[washind]

For a year my Envoy has towed my pontoon boat ok (the PCM program doesn’t seem be programmed to tow efficiently though). On my last trip, it seemed like I had a brake dragging because the truck couldn’t maintain speed and started to miss. The boat is about 3,000lbs and I tow it with the top up so there is additional wind resistance. Even though there was no message on the DIC and the engine temperature gauge wasn’t too high (110C versus 90-100 normally), it felt like it was overheating (there was also a slight smell). When I switched to neutral it seemed to coast ok (without drag).

Even though I pulled over to let it cool down, shut off the A/C, switched to 2 wheel drive and subsequently pulled a little slower, it was better but happened a second time although I made it home.

All fluids were changed in the last year but I noticed the rear diff was now down about 300ml. I didn’t detect any unusual smell there. The engine and transmission fluids were right up, clean and smelled ok.

So…

• Does anyone think the problem may have been caused by the rear dif fluid level or do you have any other tips?
• Should I consider getting a revised program for the PCM to help with towing performance?
• Is it advisable to install an additional transmission cooler?

Thanks so much,

Dave
Ps. Otherwise love the Envoy!