NHTSA Complaint #11427197 — 2011 FORD F-150

I first noticed a rapid chirping sound from the engine when accelerating on a hill while pulling a trailer. The pickup had about 135,000 miles on it at the time. This was usually associated with an automatic downshift due to the load and the hill in order to maintain speed. The sound increased over a period of a year. Then I started noticing the sound when starting with a cold engine. The sound would diminish after the engine warmed a bit, but it didn't really disappear. I finally took this pickup to an auto clinic (Sequim Automobile Clinic, Sequim, WA) with 153,000 miles on it. The manager, Marv, later told me that they found the driver's side exhaust manifold warped. He said the noise was coming from a gap at the rear end of the manifold. He improved the condition by tightening bolts, but he said the only way to really make it right would be to replace the exhaust manifold. I went to YouTube and found videos of others with this problem. Their suggestion was to replace the exhaust manifold with one that was superior in design and construction in order to keep from having the problem, again. They indicated that the problem was due to heat generated by the engine and turbo chargers in this 3.5 L Ecoboost Ford engine. The manager at the auto clinic said he hadn't seen the problem from others with this engine, but the others weren't putting the engine under as much load as I am. I'm pulling a trailer of about 8500 pounds. I'm pulling it over passes about 5,000 feet in elevation and in a one month period traveling about 3,100 miles. The manufacturer rates this particular pickup to pull a trailer up to 11,500 pounds. I've also watched videos of major endurance testing by Ford that indicated no problems after over 150,000 miles of operation under grueling conditions. I don't know if there is a safety issue here, but I know of no other place to report it. Certainly the exhaust manifold should be able to handle the heat generated in normal operation.