rrnb

I've got a mysterious knock once in a while at low rpm it shudders and runs really rough, it smells like its running really lean and the thing is that it doesn't do it all the time and hasn't thrown me a check engine light or code or anything. When it does this,i turn off the ignition, let it sit for a minute, and restart it and it runs great? About 3 months ago, i installed a cold air intake and Bully Dog tuner. I thought maybe it was because of the tuner so i uninstalled it and the truck is still inconsistently misbehaving. I also haven't taken it in to see a mechanic yet because i most likely wont be able to reproduce the issue. Has anyone else experienced this? Or does anyone have any suggestions or tips? I have been servicing her religiously at the local ford car lot using only oem filters and oil...Please HELP

rrnb

Drove to work and home for the last two days and it ran great, then this morning again, low rpm at a stop sign my truck starts chugging an shaking. The oil pressure is good, rpm between 500-600 in drive. Once I give it throttle it smooths out but doesn't go away till I turn off the ignition for a bit and then restart it...WTH! Is this? I'm not knowing?

mguerin91298

I had the same thing. It was the seal for the chain tensioner. At idle the pressure drops just enough with the leak to allow the chain to slap around throwing the cam timing off.

rrnb

Wow! I have to say that's what I was afraid of hearing. No warranty left. I've had oil changes done before the mileage intervals and only had Ford perform them. Pretty upsetting to read about this known issue. Wouldn't a check engine light come on? My oil pressure seems constant and doesn't drop when it's running rough.

rrnb

Truck was running excellent. Then today again started acting up again. At least this time the check engine light lit and gave me a code P2196 O2 sensor signal stuck rich. Gonna take her in and see what's up now. Hope it's not major!��