Vibration in an F150 Truck

Is this road-speed related or engine speed? Ie does it do it at the same engine rpm whatever gear/however much torque converter slip there is? Or even out of gear?

Engine speed. If I am slowing down and the clutch is engaged at 1000 RPMs it occurs in any gear.

Sounds like the same problem I had in my F150. Turned out to be a worn U joint in drive shaft. Vibration went away after U-joint was replaced. Vibration was there long before the joint became noisy enough for me to hear when driving.

Elnav

In the original problem, the noise was there when the vehicle was stopped. How long after you stopped the truck did your driveshaft stop spinning?

Do you have a load on the engine at 1000 RPM (seems quite low to be driving) or is it just idling?

You might plug it in to a diagnostic computer while under load (or whatever conditions cause the vibration) to check if it appears as though all cylinders are firing. I have seen instances where an engine miss only occurs at certain conditions and they can come across as a vibration even though they are a repetitive misfire.

Portable diagnostics can be used while driving.

whether it's idling or coasting it occurs. When i disengage the clutch and the RPMs hit 1000 it occurs momentarily till it hits low idle.

It may simply be that the frequency of the explosions in the engine at those rpms has matched a natural frequency of oscillation of the exhaust system; it's behaving like an organ pipe. If so, then apart from replacing it with one of a different design, no amount of re-torquing bolts will make any difference.

Lotus and Subaru vehicles can exhibit the same phenomenon.

for the first 60,000 miles it never did this, then it started only occasionally. It has been tuned up and inspected several times. Nothing helped.

Other than this silly, annoying (loud) noise I am perfectly happy with the truck. It should have no problem making it to a quarter million miles or more.

Perhaps the exhaust has partly corroded and one of the baffles inside it has fallen off.

Is this the same one that was blasting up the Cranes Farm Road last night? Cor!

Stinky

Short of buying new ones and replacing them, that was the one thing I could not completely check. A flexible rod and tapping the baffles was as close as I could get to them. No discernable rattle at that time.

I can live with the noise but it's embarrasing while sitting in traffic or around town. I take pride in keeping things nice and in good working order.

I had the same thing with my Ford Ranger -- and Stinky got it right. I replaced the muffler and the noise went away. Baffles were rusted out and loose.

Is this a noise or an actual vibration?

Aural vibration. No shimmy or shakin.

I did find one I.D. tag that was between the heat shield on the cat. conv. and the CC itself. I grabbed it with very fine needle nose pliers and slid it out through the slot on the shield. I thought I finally got the little bugger causing the noise. That was about 40,000 miles ago. Still makin noise!!!

Worn motor mounts.

Possible

I've checked the bushings and bolts to make sure they were snug and isolated. Do you think this would cause the exhaust to resonate or would it tend to cause more frame rattle?

I have always had Fords so I may be of help

1 ford hangs a balancing devise ,that is a piece of tubing ,that likes to fall off you would never know it by looking at the exhaust ,after it falls off, I see them on the side of the road ,and it happened to me.I suggest looking at a similar truck that has the same setup and see if it is the case.

2 I had an evil noise that came from the tailgate latch that drove me nuts could be the same thing ,try lubing the two points that latch the gate.

3 It is possible you have lost a balance weight on the driveshaft .To confirm try a hose clamp on the shaft at four marked positions and rotate as necessary to balance the shaft .The head will provide weight .If you get the correct diagnosis send it out for balancing or just leave the clamp.

4 check the rear end for fluid f150 s are famous for loosing fluid jack it up and check the lash and the u joints could be the cause as well .

All simple stuff if none of the above works, slam a wood block in the exhaust to isolate the noise ,diagnosis is usual simple rather than all the other complex assumptions .

I hope this helps

Because you mentioned the frame in your original post, I wonder if the problem might be in your suspension or wheel alingment.

You also mentioned that the truck didn't do it for the first 60,000 miles. Did you change or repair anything in the truck at or before that time? I'm thinking that a new part was installed and became worn just enough to cause the noise.

Problem is you have a F150, if you had wanted quiet you would have purchased a Lexus.

I Dunknow how to get to the bottom of a Ford vibration problem. The company spends Millions putting them in there : -- )

one other possibility

you have not said what year or engine ?

If it is a straight 6 the exhaust manifold have been known to loosen over time .

I'm betting on the exhaust simply rattling against the frame or body try the wood block test and you should find out right away.

I also like Stinky's idea of a loose internal component of the exhaust.

The motor mount idea is common on small cars but you can rule that out with a large bar or 2x4 and see if the motor radically moves with a good yank .

I'm curious what it turns out so I can add it to my list of diagnostics.

The Lexus might not be so good for going to the dump or actually working for a living but I do agree all manufacturers strive for obsolescence .

By the way be real careful to make sure your tie-rod ends are good Ford had a "better idea" and redesigned them with deadly plastic inserts that can simply pop off with no warning.

I replaced mine on my 2000 f150 at 70k after one fell off in the driveway after being on the highway going 70 mph 5 minutes before ,there should be a recall.

I opted for old style replacements with grease fittings and everything.

On the F 150; is it an automatic or standard trans?

harmonic vibrations can come from the trans dip stick or if there is a steel vacuum line to a vacuum modulator. A loose screw under the dash or even tools and "what-nots" behind the seat or in the glove box. If all else fails check your harmonic damper; or evet the fuel cap. (hope these help)--->Rich

I knew those buggers did that! I just couldn't prove it.

Greetings Charsley99,

If what you say is correct, Noise at 1000RPM when the truck is setting still or under way, I would not look any further at the drive train.

I would start looking at your flex plate, clutch and flywheel. You did mention that it happened with the clutch engaged.

Your old clutch plate may have shed a friction causing a balance problem. The Flex-plate may have a cracked or damage diaphragm spring. The Pilot bearing may be loose in the end of the crank.

If it was in the trans, drive line, rear-end, suspention... the noise would tend to fallow the amount of force on the offending part.

It sounds like i may have raised more questions than answers.

Good luck and keep us posted.

Greetings Charsley99,

If what you say is correct, Noise at 1000RPM when the truck is setting still or under way, I would not look any further at the drive train.

I would start looking at your flex plate, clutch and flywheel. You did mention that it happened with the clutch engaged.

Your old clutch plate may have shed a friction causing a balance problem. The Flex-plate may have a cracked or damage diaphragm spring. The Pilot bearing may be loose in the end of the crank.

If it was in the trans, drive line, rear-end, suspention... the noise would tend to fallow the amount of force on the offending part.

It sounds like i may have raised more questions than answers.

Good luck and keep us posted.

I forgot to login before this post was submitted.

So this is a repost

If the noise occurs only at 1000 rpm, with or without the clutch engaged, then the problem has to be upstream of the clutch, i.e. engine or front shaft.

I haven't got all the way through the posts yet, so apologies if someone else has asked this:

What is the pitch of the noise? And its duration. Have you tried driving at 100 rpm or holding in neutral at 1000rpm to get a better location on the source?

If you think it's engine related (my bet on the info so far), then using stethoscopes, both airborne and structural, would help.

For airborne noise use a rubber tube, one end to your ear, the other you wave around the engine bay (or anywhere else you fancy) and listen.

For structural, use the long screwdriver - must be the one with the shaft all the way through the handle (I know you know that, but you never know who else is listening in!) or a long rod, and rest one end behind your ear, on the bone.

Let us know what you find

We had a similar mystery noise that would occur on a slight incline intermittantly on a 1990 F350. Multiple "experts" could not figute it out. When the transmission bit the dust and we had it replaced, the noise was gone.

cracked flywheel? I had this once on a chevy truck. Only vibrate at low RPMs

Hello there. Good old Fords, you can rely on them. I'm tending towards the transmission rather then the exhaust, although I did have an annoying rattle on an exhaust once where it had moved slightly and at just the right conditions made a most alarming din. As the noise is heard when stationary, before I'd do anything else I would get some-one to hold the engine at the specific speed and go around the whole vehicle with the old home made stethoscope, you know, the really long screwdriver you put to your ear with the other end touching the suspected source? I once found a nut that had been dropped into an engine and had made it's way to the bottom of the sump like this.

Good luck!

Don't forget, we are all desperate to know what it is, now!

Might as well throw my hat into the ring.

Harmonic Balancer.

Your are going to think I am NUTS but check your crankshaft. I have seen them break behind the front seal but before the first main bearing. It break on a angle and still turn the harmonic balancer.

driveshaft hangar bearing,if so equipt.

Gentlemen and Ladies (covering all bases)

You've given me some food for thought and covered a lot of areas that I will endeavor to check. I am a stickler for getting my monies worth out of everything. This is a 97 F150 standard 5 speed overdrive 6 cyl. It has 237,000 miles. To me thats not a lot. My average cars life span is well over 350K. Just last year I gave my youngest son my 83 Honda Shadow in pristine condition except for a small split in the seat. (almost an antique). As you can tell by the mileage it has been going on (the rattle) for some time. I just recently had the front end aligned and inspected (figured they might see something I missed) They said everything looks good. I figured eventually the problem would rise it's ugly head high enough that it would slap me in the face. Unfortunalely it remains a pebble in my shoe.

I thank everyone for there input and will take all suggestions seriously.

I AM DETERMINED!! I want at least 5 more years out of this puppy!

I had a 1976 Chevy 1/2 ton with Turbo 350 tranny that the Flex plate had a small crack in it. The noise started at about 60k-70k miles. The crack didn't go through the ring gear just between two of the bolt holes in the flex plate itself where it bolted to the crankshaft. Drove me nuts! It would only click or rattle at about 1000-1200 rpm in or out of gear. The entire crack was less than 1/2" from end to end. Took several "EXPERTS" and shade tree mechanics to finally figure it out. Replaced the transmission to try and rid the noise and it was still there (We didn't change the fly wheel ) Finally changed the flywheel and noise was gone. Just a thought.

Let us know what ya find.

Hi charsley99,

Before you go and dismantle the whole underside of your vehicule, check for this:

Catalytic converter (CC). I had a 5.0 mustang that exhibited the same symptoms at low rpm's and it turned out that the ceramic structure of the CC was damaged and floating around in its enclosure. It eventually blocked part of the exhaust, causing the engine to backfire. Once changed, all was ok.

Just a thought. Good luck.

Rick.

It was mentioned the drive shaft hanger bearing that's a very good possibility that I forgot about .

Most of these suggestions can be gone through in 15 minutes with a floor jack and a bar to rule them out ,I would love to hear the outcome ,you have me curious !!!

I suspect the Cat as well, tap it lightly and listen for the rattle.

I've read all the comments, and no one has mentioned tires? Did you have new tires installed? Tires are notorious for doing this. Even an older tire looking in good shape can bust a belt and you not know it. If it is a motor problem, someone mentioned earlier, Ford has a device that can be attached to the truck with a manual push button. When the vibration hits you push this button and it records the events as it happens. It keeps recording for 10 seconds after the button is pushed. So if you do this remember to push it in at around 950 RPMs so that it records the event. Ford can then take the device off and read what it recorded on a computer. Hope this helps.

It may be a little late at this current mileage, but a good starting place might be the question " what changed since the last time it was correct?" If you had anything in the clutch housing changed, I would suspect that. If not the only two things that are spinning at at engine speed that are not secured with bolts, and could shift position, are the ring gear on on the flywheel and the outer ring of the harmonic balancer. The variance in balance of the ring gear would be minimal if it shifted. And after this much additional mileage I would think the shifting ring gear would have failed by now. But the outer ring of the harmonic balancer could swell from oil contamination and shift. And by design it is out of balance to compensate for the non balanced crankshaft.

To test if the outer ring of the harmonic balancer has shifted, try this. Remove the spark plugs, insert a wooden dowel into the #1 spark plug hole. With the wheels chocked, and the trans in neutral, rotate the engine over by turning the front pulley. Once you have determined the highest point that the dowel rises to that will be Top Dead Center of cylinder #1. You need to be as accurate as possible. Once that point is located, you should be able to look for a factory provided timing mark on the front timing chain cover that would line up with a machined mark in the outer ring of the harmonic balancer. If the marks on the balancer ring do not line up with the "0" mark then the balancer has shifted. That will cause a vibration in the engine, and anything long and stiff attached to the engine will vibrate in tune with the engine. And that is what I think is the cause of your exhaust noise.

good luck

Sell it off and by a Chevy.

How dare you, Sir! (sound of gauntlets being thrown to the floor!)

F.O.R.D. (a.k.a "Dagenham Dustbins".)

• Found On Road Dead/Dismantled
• F..... Only Runs Downhill

Tee Hee! <hic>

Fix or Repair Daily

At the time I was shopping I tried just about every truck. Being 6 ft. 3 inches limits me to certain vehicles. (head room for one) Out of every one I tried, the 150 had the best head clearance. They had just started using the double wishbone suspension. It rode so smooth it was better than most cars. This problem would not stop me from buying another Ford. The problems I've had (excluding this annoyance) have all been minor and required no trips to the shop. Just for the typical alignment or tires. Everything else I've handled with a couple hours in the garage.

Just wish it got better gas mileage. Can't ride the bike for 60 mile commute in ice and snow.

Timing mark on flywheel lines up with timing marks, As do both marks on the pulleys and motor block. Belt did not skip a notch. Already checked.

Thanks anyway

One additional question. Does the harmonic balancer appear to wobble. If not try process of elimination. Disconnect belt or belts from front of eng. Start engine and bring to 1000 rpm. If the vibration is still there, or not, do not run more than is necessary to feel for the vibration. There is no water circulating without belts.

If the vibration is gone the suspects are; air conditioning compressor, power steering pump, alternator, water pump, or smog air pump (if equipped).

That was the easy test. If the vibration is still present without the belt(s) the next test is to remove the transmission in order to remove the clutch components. Again with the belts off, and the trans and clutch removed, Start the engine and bring to 1000 rpm. Is the vibration gone? If yes, you need a clutch assembly that is balanced correctly to your application. If the vibration is still there remove the flywheel to have it balanced by a clutch rebuilding facility.

When you run the engine without the transmission\clutch assembly in place, it may require the exhaust pipe to be disconnected from the engine. This may hide the noise you referred to initially. Don't let the sound alone determine your results. The noise is a result of a vibration in almost all cases like this. Good luck.

by the way you don't have to do this all at once, you can pick and choose as tine or circumstances permit. Just try to eliminate variables as best you can.

I am not sure what year you have, but I have 2004 5.4L with 55k miles. I have experienced two scenarios with vibration. The first being a recall item for improper lubrication of the u-joints. This was worse at higher rpm's. The other sounds identical to your problem and it started around 50k miles. I have an automatic trans that when the engine is between 1k-1.5k has this noise that sounds like it is coming from the exhaust. It seems that there is a power loss during this noise as well. The engine accelerates just not as rapidly as normal. Since the noise is coming from the exhaust and it seems to effect the power I am leaning towards catalytic converter blockage but I haven't gone so far as to replace them yet. Probably going to be my next step. Fords are notorious for catalytic converter problems and they are not cheap to replace.

OK guys. Everyone wanted to know the answer so here goes.

After 11 years (got it in 2006) I decided the muffler and pipes could use replacing. No noise but they looked like they were gonna go soon anyway, and everybody felt the exhaust was the culprit. I tore the son of a b**ch apart and found in the Y branch going to the manifolds a 3 1/2" 5/16th bolt. Aint no way it got there after production!

I figure it was either dropped in and forgotten or never located, or somehow it wedged in during handling of the pipes and freed up after X amount of miles. I should have left it another 5 years and it probably would have rusted away or eventually wear out the pipe and fall through.

Peace and quiet finally...... till the next problem or vehicle!

Thanks again for all your input.

Then I claim the prize, back at post no.11! Is there enough there for a hot meal tonight? It's been a long time since I had one, you see.......<splutter>.

Coming right up

RRRAAAAAAAAALLPHH !!! *#@9?*%

OOOh look! corn and tomatoe peels!

That is a new one on me, thanks for the update.

There sure was a wide variety in remote diagnosis, it is nice to see so much involvment on the forum.