I am looking at buying a 2000 F250 Lariat with a V10. Took it for a test drive after it hit the detailer but before the dealer shop looked at it. Minor issues are an alignment and warped brake rotors. 4x4 engages good in high and low, no leaks on the oil pan, transmission case, transfer case or differentials, 99,xxx miles.

At idle, it has an intermittent misfire...very subtle but you can feel it. At regular driving (city, 45 or less, gentle accelerations) I can't detect any misfires, but when putting my foot into it to get on the freeway, what feels like multiple misfires on the driver side of the engine associated to a sound (detonation? no ignition at all? exhaust leak?).

Told the dealer he needs to check it, they took it straight to smog and they are telling me it passed...can't see any missing exhaust manifold bolts...

This truck is REALLY clean, low (relatively) miles...hoping this is a minor issue...

Any ideas? I see that it looks like all of the visible exhaust manifold bolts are there.

 

The miss at idle may just be the coil boots, my have started doing it and the boots are going to be changed soon. The other sound may be exhaust flutter that was common in the 2000 V10, it's a resonant sound in the Y pipe and it happens between 1200 to 2800 rpm and is more noticeable under heavy acceleration and it does sound like a exhaust leak or it could be a loose heat shield on the Y pipe. I have had two 2000 V10 trucks (still have one) one had the noise one didn't, Ford fixed it by changing to a late 2001 newer (at that time) Y pipe. Still have that truck and no noise at all

Denny

 

Is it a difficult/expensive fix? Just coming from the detailer made me wonder if power washing the engine could be the issue (water on the coils/plugs)...figured another test drive when it has had the time to dry out is in order.

What is "exhaust flutter"?

 

Sounds like a bad coil to me. I was very surprised at how smooth my V10 ran with 2 bad coils. I also wouldn't be surprised if it passed emissions with the bad coils. That said, I'd make them fix it as a condition to purchase. If the plug boots are old and cracked, they let water in the plug well which shorts out the coil. Sometimes the coil can be salvaged but most likely it is shot. Washing the motor is how I ruined mine.

 

The coils very rarely go bad but water in the plug hole or cracked plug boots are the main reason for misfiring. If it has been run with a misfire the CAT is most likely toast.