I’m having a problem with my 2010 Ford Expedition 5.4L 3V. When the engine is idling, it runs unevenly, and I can feel some pretty strong vibrations. The RPMs also move up and down a little bit. It seems like some of the cylinders aren’t firing right.
Sometimes it’s hard to notice, but other times it’s really bad.
Has anyone else had this happen? Where should I start trying to figure out what’s wrong? Any help would be great!
A scanner that supports Mode 6 can detect misfires. If a misfire is happening regularly, it should be more obvious if you speed up a bit while the engine is under a little stress. The Check Engine light should blink during this.
Taking off the connectors for the fuel injectors and spark plugs can help you find out if a specific cylinder is the problem. If the engine runs even worse after you disconnect a fuel injector or coil, then that cylinder is working fine. But if the rough idle doesn’t change, then that cylinder might be the cause.
I’d probably begin by disconnecting and testing the MAF sensor, then checking the spark plugs, and then using a scanner to check the fuel trim.
Just a heads up the spark plugs on the 5.4 engines can be really tough to deal with. Like REALLY tough. There are lots of videos online that show how they can sometimes break. If you decide to replace them, be sure to do it the right way and replace all of them at once.
And have a backup plan in case something goes wrong lol.
@Paisley
I already replaced the spark plugs.
Thanks for the other possible causes. I’ll have to check those.
Clarke said:
@Paisley
I already replaced the spark plugs.
Thanks for the other possible causes. I’ll have to check those.
How old are the ignition coils? Are they all the same age and brand? Coils usually last for about 60,000 to 100,000 miles. If you still have the original coils and your car has over 100,000 miles on it, they might be getting weak and wearing out.
@Azriel
I’m not sure how old they are. The car has 265,000 miles on it now, so that could be the problem. Thanks!
@Paisley
The broken and stuck plugs were only a problem on the '07 and earlier models. The '08 and newer ones were much better at not breaking. Getting to the plugs is still a pain for the back two on each side, though.
@Mitchell
Interesting. We had a '14 XLT, and when we wanted to get the plugs changed, they quoted us something crazy like $4,000 for plugs and to replace the heads as a precaution lol.
Paisley said:
@Mitchell
Interesting. We had a '14 XLT, and when we wanted to get the plugs changed, they quoted us something crazy like $4,000 for plugs and to replace the heads as a precaution lol.
Find a different shop. I could see $4,000 for new heads, but not for a plug change. It takes me only 2 hours to change the plugs on my '07.
@Mitchell
Yeah, we didn’t go through with it. That was at a dealership in South Florida more than 5 years ago.
You need to do a ‘power balance’ test with a scan tool to find out which cylinder is misfiring.
Have you replaced the phasers and chains?
Xander said:
You need to do a ‘power balance’ test with a scan tool to find out which cylinder is misfiring.
Have you replaced the phasers and chains?
Not yet. Can those cause this problem? How can I check them without taking the engine apart?
I’m dealing with a similar issue on my 2011, but the symptoms come and go.
Does yours act up every time at idle, or does it happen sometimes?
Sloane said:
I’m dealing with a similar issue on my 2011, but the symptoms come and go.
Does yours act up every time at idle, or does it happen sometimes?
It’s usually noticeable, but when I brought it to the shop, it was barely there.
So, it could be the ignition coils, or it could be related to the timing, like the VCT solenoids. You’ll need to connect a scan tool to be sure. If it’s misfiring like that, it’s probably throwing a code.
Check your engine mounts. I don’t think that’s the problem since you mentioned the RPMs are moving up and down, but since it’s an older Ford, it could be something as simple as an engine mount. I’ve had to replace the passenger side mount on my 2017 Explorer three times.
I had this issue with my 2010 F150 with the 5.4 engine. It idled rough and knocked. When I gave it some gas, it stopped. It turned out to be the variable valve timing solenoid. It’s easy to replace yourself.
@Hollis
Is it a light valve tap or a deeper rod knock sound? When mine sits for a week, it sounds rough at first, but if I blip the gas, it goes away. I thought the oil was just draining out and it needed a little help getting things lubricated again. It would be great if a quick part swap would fix it since I’ve been sailing all week.