My truck has started to make a slight rumble/vibration that is just barely audible but can also be felt. Especially noticible when stopping and vehicle speed dropping to about 15mph and RPM is going back to idle.

Don't think it's trans/clutch because it does it in or out of gear.

I got the check something dinger which went off when the truck started. No CEL but a P0191 code this morning. FASS sounded funny while waiting to start.

Truck is basically stock, no boxes or such.

Somebody help before I get stuck somewhere...

 

Sounds kinda like a U-Joint except for the code you mention.

Crawl underneath after driving and feel the U-Joints. If one is HOT, then it is bad.

How many miles?

 

It looked p0191 up and that is Fuel rail pressure sensor performance. Can't help more than that. The only other thing could be an injector. May want to keep an eye on your oil level. If an injector is stuck open you could fill the engine with diesel pushing out the oil. Make sure oil level not rising.

 

Whats it do on a left turn from a stop? Any roughness thats not there going straight from a stop?

 

No more roughness turning either direction. It is getting worse though. Vibration and noise sound like mud grip tires, but not as loud.

The truck has 62K on the clock. It could be a bearing or u-joint totally unrelated to the codes because the truck is running fine.

At start-up the FASS made sort of a long squeak instead of its usual high pitch whine. I hope the FASS isn't going South already, its only been on for about 1 year and 18K.

 

Bearing in rear end (axle or wheel), u-joint, loose lug nuts, fan clutch

 

I checked the lug nuts and all the u-joints. The joints look fine and none were so much as warm. I'll look at the fan clutch tomorrow.

 

Do you still have that code? if its in the fuel sensing area, you will get some engine vibes there...

noticeable when stopping....do you feel it in the pedel?

 

Check your fuel pressure for me at lest......that will show what is going on from our end.

NOW for the noise....

Its got to be something in the drive train as it only happens when you are moving, at least from your description. A noise like mud tires could be a wheel bearing as they have a sort of moan/howl when they go out...but they don’t tend to vibrate though...unless its really bad....in which you would KNOW you had a wheel bearing going out....so.

Vibrations come from rotating mass.....tires, wheels, drive line, clutch, trans, carrier bearing, etc. When you check your u-joints, you need to unload the drive line to see if there is any more slop than normal. Might jack up the truck and pull the fnt wheels. Inspect the brakes....as you mentioned that its only bad when you stop.....well if you had a pad that was metal to metal......it would cause a noise like that......and with my truck, i could barley hear my pad grinding over the engine that sheered of when it let go. I had almost 30% left on the pads....so...worth checking. Also spin the tires when you get it up in the air....notice any more drag from side to side. If you ONLY get a vibration when you touch the brakes......you got a warped rotor....but usually these dont cause noise.

ALSO when you get your noise when your stopping.....saw the wheel back and forth........if the noise gets quiet and louder with the same frequency, its prob a fnt wheel bearing making noise. Further inspection will be needed at that point......see above for that......

Might have your tires rebalanced as well.....have them check for anything out of round.......when you stop, you put alot of weight on the fnt tires...and an of round tire (Which could cause a ballance issue) would make more noise at that point.

SO.....hope that can help you some.....

 

Diesel-Dan,

How do I check the fuel pressure? I'm still getting the code.

As far as the noise/vib.,

I think it's the pass. side front wheel bearing. I checked torque on lug nuts again then jacked the truck up and found the right front wheel rattles on the hub when I hit on the top sidewall of the tire.

Noise is getting louder and the vibration is getting worse too. The truck is beginning to get a slight shudder slowing through 15-10mph. Turning either way doesn't seem to effect it.

 

caltom mine is a 2wd but the drivers side hub bearing assembly sounded just as you describe and was getting progressively worse until I replaced it. Sounds like your's may be a little more advanced than mine was. I could definately feel the roughness when I rolled it when jacked up.
Dealer hub assy. is HIGH $. Google 'E. B. Atmus' if you feel you have time to wait for shipment to you. This is an SKF bearing dealer and 1/3 to 1/2 the dealer cost. (I've read on this forum somewhere that SKF is the OEM supplier) I was concerned as to how long mine would hold out before locking up so after searching the Dallas area I called around the salvage yards in Grand Prairie and picked one up at lunch one day for $100 and tax at Mid-Cities Jeep-Truck-Van -phone 972-263-1288. Counter guy there was a little weird but the price was right. Came off a 2500 gas rig which was not as heavy in the front end as ours. It's been running good since 12-06-07 when I got it, little over 10K miles ago.