Hello everyone! I tried searching this forum several times and have not been able to find this exact issue. I posted it originally in the transmission forum, but I think that is the wrong place

I have a 24' boat that with the trailer probably weights close to 5,000 pounds total. The truck is a 2005 Ford F-150 with the 5.4L engine. Roughly 85,000 miles on the truck. New spark plugs put in about 10,000 miles ago, new battery 5,000 miles ago, oil changed 75 miles ago.

When I pull my boat for long distances on the highway the truck handles it with ease. The problem occurs when I come to a stop after driving for a while the engine will start to shake and knock and the rpm drops. If I can put it in neutral and hit the gas the problem usually goes away until my next stop, if I don't hit the gas in time the truck will die.

This NEVER has happened to me unless I am pulling the boat and have driven for a while without stopping. Start and stop driving for about 10 to 15 miles doesn't bring on the issue.

Any suggestions?

Thanks in advance!

 

Anyone? Anyone?

I would really appreciate some help with this.

Thank you!