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1200 RPM Engine Vibe

texas_diesel

Lubbock Bum
So I've had a weird vibration since I've owned the truck (has 25k, I'm the 1st owner), and I think I've got it kind of nailed down. On a cold start, for the first 10 miles or so down the highway I'll get a vibrating sensation, usually just in the pedals but occasionally enough for a passenger to feel. Happens from ~1100-~1200 RPM.

- I've tried locking the trans into 1, 2, and 3, happens in each gear in the same RPM range, so its the engine speed, not wheel speed.
- Doesn't matter if in 2wd, 4Hi, or 2wd w/ the hubs locked, so it's probably not a driveline problem.
- From what I can tell from the idiot meter for the turbo, changing the boost level doesn't change the sensation, so it's not a stuck vane or bad bearing in there.

I'm not horribly worried about it, just curious right now. If it hasn't changed yet, it might never, so no big deal. I'll get worried when other things go wrong. So far no coolant or diesel in the oil, no coolant puking, no power loss, none of the normal signs of a blown 6.0. My only guess is a plugged/ bad EGR valve, but I haven't had the time to pull and clean that yet.

Anyone ever had or heard of something like this?
 
3,121
67
Michigan
Vibrating as like a tire is unbalanced? Even tho its the motor
 
Last edited:

texas_diesel

Lubbock Bum
Yes, only when engine is cold, either sitting over night , or after being shut down a few hours during the winter.

Yeah, I thought about the tires too, but I've had them rotated 3 times, and it never changes or feels like it moves. I thought it was a u-joint on the d-shaft for awhile, but there was never any extra slop in any of them.
 

blackhat620

You Had to be There
1,687
150
Arizona
So I've had a weird vibration since I've owned the truck (has 25k, I'm the 1st owner), and I think I've got it kind of nailed down. On a cold start, for the first 10 miles or so down the highway I'll get a vibrating sensation, usually just in the pedals but occasionally enough for a passenger to feel. Happens from ~1100-~1200 RPM.

- I've tried locking the trans into 1, 2, and 3, happens in each gear in the same RPM range, so its the engine speed, not wheel speed.
- Doesn't matter if in 2wd, 4Hi, or 2wd w/ the hubs locked, so it's probably not a driveline problem.
- From what I can tell from the idiot meter for the turbo, changing the boost level doesn't change the sensation, so it's not a stuck vane or bad bearing in there.

I'm not horribly worried about it, just curious right now. If it hasn't changed yet, it might never, so no big deal. I'll get worried when other things go wrong. So far no coolant or diesel in the oil, no coolant puking, no power loss, none of the normal signs of a blown 6.0. My only guess is a plugged/ bad EGR valve, but I haven't had the time to pull and clean that yet.

Anyone ever had or heard of something like this?

Could be in the exhaust system. Take it to the dealer and let them run through the exhauxt neutralization procedure. If something in the exhaust system is misaligned it can cause this. Usually happens around 1500RPM.

Your EGR valve should be fine. Leave it alone unless it gives you specific problems. Also your engine is warrantied for 100k miles.

Do you have any mods on your truck/engine?
 

texas_diesel

Lubbock Bum
Bone stock 6.0.

I was worried about the EGR because I lived in Colorado awhile, and it used to idle a LOT in the winter, probably a half hour idling to an hour of driving some days. Never had lots of blowby in the oil thought, but I'd heard lots of stuff about sooting in the exhaust side of the turbo and gunking up the EGR. Pulling it to check it isn't hard, just a gasket if you aren't carefull taking it out.

Whats this exhaust procedure?
 

A_G

wuh?
3,188
74
Tulsa, Ok
all diesel do that. Some are more noticable then others.

Go listen to a old 6.5 chevy run they make all kinds of noice and vibrate even at idle.

Such high compressions and the parts are machined to fit really tight when warm (metal expands when hot)

so when its cold the metal contracts just enough to cause a vibration/noise.

The rpm probably doesnt matter, just at the rpm do you feel it.
 

CowboyBilly9Mile

Charter Member
7,118
442
USA
What happens when you rev it to the same speed, cold engine and all, but you're in park sitting in your driveway?
 

texas_diesel

Lubbock Bum
What happens when you rev it to the same speed, cold engine and all, but you're in park sitting in your driveway?

Happens sometimes, usually when the truck kicks itself up to the high idle, not when I throw the upfitter switch wired to the high idle.

A_G, yeah, I'm figuring it's nothing major that's wrong, just figured I'd check in and see if I was missing another major problem on the 6.0
 

A_G

wuh?
3,188
74
Tulsa, Ok
no im just saying, but if its under warranty still and you got time go ahead and take it on down to the dealer.

I dont think theres anything wrong with it, but they might find something else.
 

blackhat620

You Had to be There
1,687
150
Arizona
Whats this exhaust procedure?


Basically they check the exhaust system over for any damaged parts, mounts etc and also loosen all connections (ie y-pipe, down pipe, etc) and realign the exhaust system. Then carefully re-torque everything in proper sequence. The 05 and earlier trucks also had a revised turbo pedestal that could be installed to help with this problem.


texas_diesel said:
I'd heard lots of stuff about sooting in the exhaust side of the turbo and gunking up the EGR. Pulling it to check it isn't hard, just a gasket if you aren't carefull taking it out.

If the EGR is sticking it would not cause the symptoms you are describing. No need to pull the EGR and look at it, because a visual inspection will not tell you if it is operating properly. The EGR valve must be tested with a range of motion test, performed by the tech using a diagnostic computer.
 

blackhat620

You Had to be There
1,687
150
Arizona
all diesel do that. Some are more noticable then others.

Go listen to a old 6.5 chevy run they make all kinds of noice and vibrate even at idle.

Yes all engines vibrate (both gas & diesel), but the 6.0 had issues with this around 1500 RPM and it was addressed by FMC. Also a 6.5 Chevy is in no way comparable to a 6.0. You cannot compare two different engines when trying to diagnose a problem with a specific engine.
 

A_G

wuh?
3,188
74
Tulsa, Ok
Yes all engines vibrate (both gas & diesel), but the 6.0 had issues with this around 1500 RPM and it was addressed by FMC. Also a 6.5 Chevy is in no way comparable to a 6.0. You cannot compare two different engines when trying to diagnose a problem with a specific engine.

it was an example
not comparison.

Most everbody has heard a older chev diesel run (sometimes not) and it was the most common and obvious one i could think of right off hand.
 

blackhat620

You Had to be There
1,687
150
Arizona
it was an example
not comparison.

Most everbody has heard a older chev diesel run (sometimes not) and it was the most common and obvious one i could think of right off hand.

Example or comparison, the 6.2 & 6.5 still has nothing to do with the 6.0. If the driver is feeling a vibration in the cab with a 6.0, (or 6.4 or Duramax), there is a definite problem. Modern diesel engines are very smooth, and the cab is very quiet with no vibrations do to modern vehicle design and build.
 

A_G

wuh?
3,188
74
Tulsa, Ok
ok fair enough, you take over...your the ford tech anyways, just thought id throw my .02 in.
 

blacksnapon

Moderator
Staff member
you might try this

TSB
07-5-11 VIBRATION/HOP AT 40-48 MPH (68-77 KM/H) - (8.0 HZ) - TRAILER HITCH EQUIPPED VEHICLES ONLY

Publication Date: March 1, 2007

FORD: 2005-2007 F-Super Duty


ISSUE:
Some 2005-2007 F-Super Duty vehicles with a long wheelbase of 156", 158", or 172" (396, 401, or 437 cm) and equipped with a trailer hitch may exhibit a vehicle vertical vibration, often described as "hopping", on smooth or coarse road surfaces in the 42-48 MPH (68-77 Km/h) speed range. Although this behavior is considered normal for an over 8500 GVW truck, some customers may be sensitive to the concern.

ACTION:
To improve the 42-48 MPH (68-77 Km/h) vertical vibration, follow the instruction sheet included in the Damper Service Kit.

NOTE: THE INSTALLATION OF THIS DAMPER WILL NOT IMPROVE RIDE ON SEGMENTED CONCRETE HIGHWAYS, STEERING WHEEL VIBRATION/SHIMMY, OR GENERAL HARSH RIDE CONCERNS.



PART NUMBER PART NAME
5C3Z-5D008-A Damper Service Kit
 

blacksnapon

Moderator
Staff member
i wonder WTH does a trailer hitch have to do with it?

Also he said it was the same at all wheel speeds, always at 1200rpm wheel speed was never an issue...
vehicles equipped with a trailer hitch have a different suspension setup. Tell me, how fast would you be going at 1200 rpms?
 

Truckin4life

Texas Chapter Leader
after the post, that was my first guess was a suspension difference,
As for the speed, i do agree with you, but if he said that wheel speed is not a factor its only the rpm's locking it in first second and 3rd made no difference, but only in wheel speed. would that not be a factor?
I am no ford tech or no master mechanic by any means, just going from what ive been taught and the information provided...
Also what does the dampner do?
Better question, what does the dampner dampen?
 

blacksnapon

Moderator
Staff member
Many manufacturers, instead of repairing the source of a vibration, will hang a weight on it. You've seen exhausts, differentials, transfer cases , etc with weights, thats all they are for. One thing I've learned, always cover all possibilities, especially now with so many people sceptical of a dealer techs competency.
 

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