So my truck runs and starts fine but after I start it and it warms up I get a tap coming from the back of the engine / tranny. I know it's not rod knock and it only happens Everynow an then. I also noticed I get some engine back/missfire and it can idle a little rough. It doesn't happen everytime though. I'm thinking the rough idle is a dirty MAF sensor. Once I switch to drive or reverse everything an all noises go away. I've noticed if I first start the truck itll idle an run fine but after I drive and then put it back into park it will usually start doing it again. I ran the obdII and its not throwing codes but it isn't passin all the I/M things at the top of the meter. Maybe exhaust leak? Idk any ideas would help. Its really confusing . Cause in drive it runs like a top an pulls hard but in park it sounds like a Chevy Help me out yall
Those years are bad about snapping intake manifold bolts. That's your problem. It's a pain to fix. Take it to a shop trust me.
Where is the idle are control valve? How could it snap an intake bolt? Basically Y'all are saying the rough idle is a vacuum leak around the manifold? This could also explain why the emission tests in the obdII fail. How does this explain the tap though? On a side note it's been cold as shat around here recently . I've had the block heater plugged in but it has been commonly started in the morning at about -15 to -20 degrees if that could have something to do with something cracking or whatnot
Tap could be a number of things... Hard to make a guess without hearing it. Mine has a tap also and I believe its a lifter. You can hear it when engine is cold but once warm, it goes away. Could be the 217k miles on it also....
Im assuming they get hot and weaken over time and snap off from vibration. never kept my 150s long enough to fix the ticking ha ha
you will have most luck pulling the throttle body off and cleaning it super good (2cans of tb cleaner) and blast the iac too and get electronic cleaner and shoot the maf. If u clean it and it still acts up do a smoke test. Sent from my iFord f150
