Greetings,

Yesterday my F350 started making a tapping noise. Initially it was under load (uphill, accellerating). On the way home the tapping became continuious, but changed with engine rpms. In addition, it started knocking a little on hills (of course, I had a ton of wood in the back, so this may have contributed to the knocking).

Today, it taps all the time, whether cold or hot, under load or not; the only change is the speed and loudness of the tapping, which changes with the engine RPMs.

I did a visual and tried to feel around for looseness/play and vibrations in the vicinity of the tap (front passenger side cylinder), but couldn't come up with anything. I can't figure out where it is coming from exactly, though.

The truck has 22000 on the odometer, recently had an oil change (has good oil pressure by the idiot guage), and doesn't seem to suffer from a loss of power.

Anyone had a similar experience?

 

I have the same truck and engine. I’ve been told to check for loose exhaust manifold bolts as this was a common problem on these engines. I don’t have the tapping sound but I was also told by someone else that a tapping sound could be high pressure exhaust gases leaking out through a loose exhaust manifold. Also check all the smog pipes and filters and all the vacuum lines, filters, EGR setup, etc etc. Hopefully it’s not internal….

 

Thanks. I suspect it probably is an exhaust leak by the sounds of it, by I'm a worry-wart. I can't imagine that the trouble would be internal with so few miles on it.

 

Put one end of a piece of hose to your ear and the other end to parts of the engine to pinpoint the noise.

 

are you sure you have only 22,000 mi? i ask because that is sure not a lot of miles (~1500 mi a year)

 

Well, I have to take the previous owner at his word that he didn't tamper with anything, but I also have a document from the Ontario Ministry of Transportation that shows it only had 32125 Kilometers on it at the time he purchased it (June 2003). It now has 35615 on it, which is just shy of the 22000 mile mark.