Rough Engine Idle

[Alexander Tan]

I've been experiencing my engine having rough idle after driving few miles on the freeway, when I exit the ramp and on full stop, the engine has the tendency to idle rough like it's almost about to choke/die then recovers. When this happens, I rev the engine couple of times and it comes back to normal. Could this be faulty VVT solenoid? Engine mount? I just replaced trhis two years ago. The engine runs fine on the freeway, only when I stop that I experience the rough idle. I don't see any error code on the OBD which is strange or have a check engine light on.

 

[99WhiteC5Coupe]

I've been experiencing my engine having rough idle after driving few miles on the freeway, when I exit the ramp and on full stop, the engine has the tendency to idle rough like it's almost about to choke/die then recovers. When this happens, I rev the engine couple of times and it comes back to normal. Could this be faulty VVT solenoid? Engine mount? I just replaced trhis two years ago. The engine runs fine on the freeway, only when I stop that I experience the rough idle. I don't see any error code on the OBD which is strange or have a check engine light on.

Year, make, model and engine?

Clean the inside of the throttle body bore and the butterfly valve.

Ensure engine air filter is not severely clogged.

 

[Alexander Tan]

I’ll give that a try. Thank you for the recommendations.

 

[Alexander Tan]

I have the 2010 Ford Expedition Limited with the 5.4L engine. I think they call this the 3rd generation

 

[Stephen Dunster]

I would look at the idle air control valve. The two holes in the valve are on each side of the butterfly in the throttle body and piston regulates air flow during idle when the butterfly is closed. I have had carbon buildup on the piston cause similar symptoms. I just removed it, flushed valve and ports with carb cleaner and reinstalled.

 

[arc1847]

Throttle body and idler control valve could certainly be the case so check those. I had a similar problem on my 05, but it almost always occurred after I had been pulling my camper and would shift to reverse to back it into a spot. As soon as I shifted into reverse it would idle rough and then die. I could immediately start it again with no problems whatsoever. I replaced the Variable Cam Timing Solenoids and the problem went away and the engine ran better all the time. I think the VCT problems develop slowly enough that unless you're really paying close attention you don't notice it until things are really bad.

 

[Alexander Tan]

Throttle body and idler control valve could certainly be the case so check those. I had a similar problem on my 05, but it almost always occurred after I had been pulling my camper and would shift to reverse to back it into a spot. As soon as I shifted into reverse it would idle rough and then die. I could immediately start it again with no problems whatsoever. I replaced the Variable Cam Timing Solenoids and the problem went away and the engine ran better all the time. I think the VCT problems develop slowly enough that unless you're really paying close attention you don't notice it until things are really bad.

I will be replacing the VCT valves since I have the the intake manifold removed to fix the coolant leak on the coolant heater pipe which is a pain to remove to replace a $10 "O" Ring.

 

[Alexander Tan]

I would look at the idle air control valve. The two holes in the valve are on each side of the butterfly in the throttle body and piston regulates air flow during idle when the butterfly is closed. I have had carbon buildup on the piston cause similar symptoms. I just removed it, flushed valve and ports with carb cleaner and reinstalled.View attachment 76772

Very good point... I'll check on this while I have the intake manifold taken out to fix the coolant heater pipe O Ring.

 

[Chencho]

I know this is old but I'm having same issues. What did you find out to be wrong with yours?