Car is slow to start, shakes occasionally, and smells hot… but runs fine?

Question

I am driving a 2000 Ford Explorer with 140k miles on it. Although the car runs well, it feels like it is on the verge of a breakdown that I'd like to stay in front of if possible. When I start the car, it puts a little slowly, but eventually starts. In the couple hundred times I have started it, it has only died post start (ran on second) once. When I am stopped at a light, the car shakes a little bit. Lastly, I notice the smell which is basically smells like something is hot. I have no lights on and oil/temp all seem to be fine. I had it in a shop a couple months ago and they had assured me it should be running fine, but I cannot seem to stop anticipating a break down. Any ideas?

Also not sure if possibly related, but the electronic keys I have with the car can barely unlock it.

Answer 1

I also had a 2000 Ford 4.0L OHV V6 and experienced similar symptoms (rough idle, intermittent no start, but no hot smell). In my case, it turned out to be the Idle Air Control Valve, which is a small silver cylinder located on top of the plastic air intake manifold that is placed on top of the engine. Its main function is to let enough air into the engine when your foot is off the throttle to keep it idling - when it starts to jam, you experience no-start symptoms that are helped when you push on the throttle. It is a cheap enough part to replace or you can clean your existing one using brake cleaner; be sure to dry it completely before reinstalling.