edit: i was assuming it's not the rear differential since it sounds like it's under the hood & i feel it in the pedal/floorboard.

 

Mine does the EXACT same thing! I also thought it was the right front wheel bearing. I changed the bearing and it was bad ( some play and abs light on). No more play and abs light off, but sound is still there! I was also thinking exhaust touching cab. I have 5" exhaust, so I figure tolerances are closer. You described it perfectly! Please let me know your conclusion.

 

you got me thinking... your's is the 2000 in you signature? so that engine has a very similar up & down pipe orientation, and probably the exhaust pipes, cat, hangers etc too, correct?

 

lol! so it's not just me! haha!
funny thing is i was thinking about running a new turbo back if the pipes are the problem

oh also forgot to mention: my truck is an auto, not that it matters lol!

I just can't see any chance of the flywheel or transmission floating in any way/shape/form... the more i think about it, it's just got to be am exhaust pipe!

 

Yes, 2000 F350. Also an auto.

 

crawled all over/under the truck this AM. found that the clamp on the downpipe/turbo interface wasn't all that tight, but i don't think that was the issue.

no soot or anything around it. No soot around either uppipes either! so why do i still smell exhust in the cab & hovering over motor? idk...

I did find that the downpipe is about 1/8" away from the passenger frame-rail. it appears to have touched the frame from time to time, but not enough to wear either one.

after i checked/tightened every clamp i could reach, i tested it. still vibrates just like it did. BUT i did check the rpm that it was vibrating. right about at the 1750rpm tick mark. the truck is noisier there than at any other rpm anyways...

 

One of these days (when it cools down in Florida!) I will crawl under there and take a look. You have given me more to think about. I will check rpms. I have noticed sound is worse if the road cambers away during the left turn. Does that make sense? Like it is putting more load or G-force in that situation. One of us will eventually figure it out!

 

yep! the more body roll during the trun (like on a suface that's crowned away from you), the worse it seems... lol i hadn't thought about that specifically, but it's true!

 

Not sure if this helps but I know with the f 150's I would guess you had a vacuum hub going bad and it was trying to engage the hub when turning. You might want to check it. We just did an f150 for a gent and it cost him about 1100 bucks by the time we were done. His got so bad it would try to engage accelerating in a straight line and he ruined both hubs and one wheel bearing

 

mine's a 2wd, but i really appreciate the info! might help picanins!

Thanks for the input. Anything is worth considering! When I changed my right front wheel bearing I put new vacuum hose on as well (both sides right and left). Hubs seem to be engaging and disengaging fine. I usually do it manually but have checked the auto feature recently and it worked.

I'm willing to investigate it further if you can tell me what to look for. And why would it only be on a left turn?

Turd, is your truck 4wd?

it's just 2wd. i still never got to recheck the bearings tho lol

with old motor mounts it could shift and stay over there also i had that problem getting on the freeway hard on the throttle and it would be hitting all the way down the freeway.

thanks man! motor mounts & body mounts are still suspect for me, since the truck has 225k on it & the cab was pulled (at least) once before

I may have the solution, I have a 2001 Excursion and it had similar noises coming from the passenger side footwell, I replaced the balls joints, tie rods and pretty much every steering component except the box, I put new leaf packs new hangers and new bushings as well as sway bar links, still made noise. So then i was looking at the body mounts and notice some rust, I ordered a urethane body mount kit from Daystar, I only replaced the front 6 mounts, Guess what no more noises! The body mounts get compressed and the metal sleeve inside starts moving around and hitting against the bolt as you drive, You can try greasing them but they are still gonna make some noise. I didnt want to put the factory ones cuz i figured the same thing would happen over time. The urethane are harder but theres no noise at all and they wont compress overtime like the rubber ones did. Daystar Part#KF04050BK (BK Just means black)

thanks! do you think 225k would do that to mine? not much rust under there from what i could see

 

Thanks for the input. Anything is worth considering! When I changed my right front wheel bearing I put new vacuum hose on as well (both sides right and left). Hubs seem to be engaging and disengaging fine. I usually do it manually but have checked the auto feature recently and it worked.

I'm willing to investigate it further if you can tell me what to look for. And why would it only be on a left turn?

Turd, is your truck 4wd?

 

down pipe clearance is a must.mine is a 97 and we have to dent our firewalls to fit bigger down pipes.at first i thought i had enough clearance but when i turned i could hear it touching the firewall.had to go back in and do some more hammering.

 

gotcha! i'll try another looksy when i get home. if i can, i'll grab some pics.


well, from what i'm gathering from you guys is that if i have a bit of body roll from loose mounts & engine roll from bad engine mounts, then that 1/8" clearance between the frame and the downpipe means it's probably touching lol!

 

Thanks Cory. Was it any turning or only one direction? I will check the clearance. Turd (OP) apparently checked his to no avail, but that's not to say it couldn't be my problem.

 

mine was turning left.

 

with old motor mounts it could shift and stay over there also i had that problem getting on the freeway hard on the throttle and it would be hitting all the way down the freeway.

 

I may have the solution, I have a 2001 Excursion and it had similar noises coming from the passenger side footwell, I replaced the balls joints, tie rods and pretty much every steering component except the box, I put new leaf packs new hangers and new bushings as well as sway bar links, still made noise. So then i was looking at the body mounts and notice some rust, I ordered a urethane body mount kit from Daystar, I only replaced the front 6 mounts, Guess what no more noises! The body mounts get compressed and the metal sleeve inside starts moving around and hitting against the bolt as you drive, You can try greasing them but they are still gonna make some noise. I didnt want to put the factory ones cuz i figured the same thing would happen over time. The urethane are harder but theres no noise at all and they wont compress overtime like the rubber ones did. Daystar Part#KF04050BK (BK Just means black)

 

My Ex barely had 200k when i noticed the noise and it took over a year to figure it out, Even most mechanics where perplexed my body guy suggested body mounts and that was it. Most likely the one right under the passanger side u can pull the bolt out from under the carpet in the footwell theres a rubber plug there, grease it up and see if u notice a difference. or leave it out and see if u notice a difference.

 

awesome thanks! was it a torx or hex head?

 

Torx head bolt like the bed bolts.

 

thanks! imma guess (& hope) they are t55, cause i have a t55 for my ford ranger's bed bolts lol

 

i tried several times today to recreate the noise with somebody riding with me. it wouldn't make the noise lol! maybe it's fixed lol

 

Murphy's law!!

 

haha! i ran it hard on the way home yesterday & nothing... lol all i did was tap on the pipes, pull them around to see if i could make them touch something, tightened the clamp on turbo, and bled out the crap in the water separator lol

tomorrow i'll be back in it, & ill see what happens...

 

ok, i tightened the turbo-to-downpipe clamp just a bit more about a week ago (It felt like it might have loosened just a bit since the original tightening).

RESULTS: the actual grinding/vibration from before is gone during left turns!!!

BUT the motor is still very loud & vibrates a bit excessively at the 17-1800rpm band (like it's always done).

CONCLUSION so far: i'm thinking its a motor or body mount that could use replacing

 

bonus: i did a cat delete & had a chance to fart around with the DP position while someone else was checking the turbo to DP clamp... no more vibration at 17-1800rpm!!! sounds like it should

 

Well done! Didn't need to break out the welder either?!?

I figured out where my noise was coming from too, and fixed it. Exhaust was rubbing on the frame at the bottom of the downpipe when I turned left. I couldn't believe how such a small area of contact could make so much noise!

 

ha! same location on my truck lol! & that's right, no welding like i thought i would have to!