Engine hesitating

I was driving my 2005 expedition and after stopping at a store it suddenly started hesitating while driving. Also when stopped at a red light it would surge or jerk suddenly.

I had just put gas in it that morning. Drove it for about 20 minutes before it started doing this.

So I headed home keeping around 35 mph. At red lights it would surge a little. Driving it would hesitate occasionally. About five miles from home, it stopped the surging when at a red light, and seemed to not be hesitating.

That was a week ago. Today drove it for the first time since and there’s no surging when stopped but a slight hesitation when accelerating from a stop. I put a gas additive in it in case I got bad gas, but I don’t know if it’s the fuel pump, fuel filter or bad plug?

I’m a 70 yr old woman so I can’t fix it myself. If it’s a fuel pump, about what should it cost to get it fixed? Fuel filter? Plug?

What else might it be?

Thanks for any help.

There are quite a few things that can cause this. A really good place to start would be to stop by any auto parts store as they will usually scan your vehicle for diagnostic trouble codes for free. The large chain auto parts store do at least such as Advance Auto Parts, Autozone or O'Reilly Auto Parts.

Off the top of my head it could be the fuel pump, fuel filter, spark plug, spark plug coil, vacuum leak, fuel pressure regulator, air filter and more.

Fuel pump would likely cost $650 or more. It's 3+ hours of labor and $200 or more for the pump assembly. Fuel filter should be $100 maybe a little more, it's 1/2hr of labor plus $20-30 for the filter, plus if you have a hazardous material fee for the drained gasoline you'd have that. Spark plugs would be $500+, it's 3 hours of labor plus the cost of the plugs.

How many miles since spark plugs were changed? Mine were waaaaay past due, changing plugs smoothed idling right out, & I picked up a few miles per gallon from what I was getting.

whtbronco and EngineerMike hit the highlights and it could be any of those things, including the Variable Cam Timing (VCT) system...solenoids, phasers going bad, etc. If you have a trusted mechanic I think diagnostics are a good course rather than guessing. If you're comfortable with a smartphone, Bluetooth and navigating menu apps, FORScan Lite is an available app and you'll need a Bluetooth OBD adapter such as OBDLINK MX+ to plug into the diagnostic port below the dash panel, about a $140 investment. In addition to reading the trouble codes, it can show real time sensor readings and calculated outputs to narrow down where the problems are. There are setup and use tutorials on YouTube and this forum of course can help.

Could be lots of things, but you might be describing a misfire. On these Expeditions those are most often caused by bad spark plugs or coils, a bad vacuum leak, or the Variable Cam Timing system as others above said. Lesser chance it is a fuel related problem or transmission related, but not impossible. Is there a Check Engine light on? If so, have a mechanic check the code associated with that check engine light. If you provide the mileage on your Expedition and last time it had new spark plugs, coils, fuel filter or any other work, we could speculate a little bit better. But still just speculation. Plugs and coils will run you a few hundred dollars, vacuum leak about the same. If its the VVT system or trans it could be $2-3,000. You might want to do a visual check, make sure all wires and hoses are plugged in, make sure its nothin obvious before taking it to the mechanic. These trucks are old and they will have issues.