Hi! I have 2007 4wd F150 Lariat, 5.4 Triton and have weird vibration. When engine starts, heavy vibration for 5-10 sec, like misfiring but it is not misfire. Then it settles. And when I give revs it comes again until idle settles.. Could bad e-fan clutch do this?

 

I wouldn't think so. Is the fan wobbly or broken? that's the only way I could see it causing vibrations like described.

Your description sounds more like maybe a phaser or misfire problem, but need more info. Any DTC stored?

 

After checking water pump & fan alternator assemblies suggest to Chk bearings in idler & belt tensioners would be my immediate thoughts??

 

Hi, thanks for suggestions, but I dont think it is neither of those. If idler or belt tensioner bearings were bad, problem would be on all the time. Don't believe on phaser problem either, has been serviced not so long ago. And misfire it isn't. I've have read on this forum and some others that bad e-fan clutch can cause symptoms I mentioned in 1st message even there wouldn't be obvious looseness/gap in fan. As I said this vibration appears on startup and sometimes on idle and when driving on level road with surface throttle. So when torque is on even little, vibration disappears. This made me think if clutch twitch when torque is not on, meaning it isn't totally broken but going bad. And couple weeks ago there was chirping sound from engine when engine was hot and had driven all day with heavy load and trailer full of furniture. It got louder with revs on and when I relased throttle it slowly went quiet with chirp frequency getting smaller. Transmission is in good shape, torque converter has been changed week ago. This is super annoying problem that I wanna get rid of without selling my F150 or change all f.... parts in my car. And no DTC's.

 

I would suggest that you take the serpentine belt off and make a cold start to see if issue exists with the belt removed.
Just a question - was flex plate inspected when torque converter was changed?

 

Maybe I test that. Flexplate was inspected on TC change, no damages in that.

 

I second the idea to remove the belt and run it for a minute.
After observing that, turn the engine off.
While the belt is off turn each of the pulleys by hand and feel for roughness in the spinning action and listen for noise out of the ordinary. Look and feel for any side to side wobble. Turn the fan by hand also and observe.
Maybe this will uncover something. If not then you may just want to go ahead and replace the fan clutch if there are previous threads indicating it can cause your issue.

 

I also agree with taking the belt off temporarily. I would also consider low fuel pressure since it seems to just happen briefly at startup and when you goose it. Other thoughts are engine mounts and loose engine to transmission or tranmission to driveshaft bolts.

 

Has the Fuel Pump Driver Module (FPDM) ever been inspected? It's mounted above the rear axle on the F150s. As gutterdun mention in post #8 this might be a fuel pressure issue.

FPDM is very easy to inspect and change if necessary. BTW Crown Vics, Town Cars and Montegros all use the same FPDM and it in the trunk out of the weather on those vehicles ripe for the picking. You may need to confirm part numbers to be sure but my 2007 F150 4.6L uses the same.