LMM: New Noise...

[wilrob]

Okay lads, got a new noise that I cannot identify. It sounds almost like a more metallic rod knock, but the motor seems fine to me.

Symptoms: only does it under load, increases with RPM (starts at 1500ish), can only hear it when next to another car on the left side, no codes thrown. I also noticed I hear the exact same noise when I put it into drive or reverse, but only once obviously. I am 99.9% sure it is not coming from the motor, so I am guessing trans, axle, front diff or somewhere else in the driveline....

Any internet diagnosis is welcome at this point

 

[Hambone]

Alright here it goes...
I’ve had this happen twice on two different dmaxs
Would of bet the farm on a bad lifter.
Turns out it was the alternator both times
One was the internal bearing
The other when I took the belt off the pulley fell right off
I’ve also had the compressor clutch make a similar noise when it locked up

 

[wilrob]

Alright here it goes...
I’ve had this happen twice on two different dmaxs
Would of bet the farm on a bad lifter.
Turns out it was the alternator both times
One was the internal bearing
The other when I took the belt off the pulley fell right off
I’ve also had the compressor clutch make a similar noise when it locked up

I would be okay with a bad alternator , but have not seen any signs (voltage being weird?) it sounds like the rod knock on a small block chevy, but the motor is healthy from what I can tell... looks like I'll be pulling the belt tomorrow and fidgeting with it some more.

 

[wilrob]

Its definitely the same noise thats coming from the gear selector(?) is there anything in trans that could make that noise with RPM?

 

[Novak]

I know you’re a smart guy so let me say that first!
I would honestly shoot for the simpler things like a loose strap or check transfer case etc. If it’s audible to be a metallic knock that would make me believe it’s an exposed part within the drivetrain so a jack and some good ole shaking out might find it. My cv axle made some weird metallic pinging noises long before it started slinging grease.
Have you noticed any odd vibration?


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[wilrob]

I know you’re a smart guy so let me say that first!
I would honestly shoot for the simpler things like a loose strap or check transfer case etc. If it’s audible to be a metallic knock that would make me believe it’s an exposed part within the drivetrain so a jack and some good ole shaking out might find it. My cv axle made some weird metallic pinging noises long before it started slinging grease.
Have you noticed any odd vibration?


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My CVs are definitely suspect, they need some TLC, but the correlation with the RPM is what's getting me. No odd vibrations, just a metallic clacking noise starting at 1500.. I looked at some of the broken flexplate threads and thats about as close as I can describe it.

 

[Hambone]

I’m watching this one close!
I love a good mystery

Transfer case trying to engage maybe?

 

[wilrob]

I’m watching this one close!
I love a good mystery

Transfer case trying to engage maybe?

Im glad I can provide some entertainment :roflmao:

I don't think its an injector hanging, not that type of sound nor do I see other signs, it's possible it's an exhaust leak, but that would be far fetched too. I'm still leaning towards something in the bellhousing area. Maybe converter chatter? I would get a video but I would have to film from a stoplight next to another car to hear it.

I also threw a glowplug code a while back that I just keep clearing, so maybe the GP came loose? That would be easy LOL

 

[wilrob]

Update: I have had to drive it some more and yank on things underneath, and I am now starting to lean towards the drivers side front hub/axle area. It is much more audible on he drivers side, and the symptoms are suggesting a bad wheel bearing or CV joint. My question is, if a bad CV was making the noise, would it follow the RPM? If its not spinning I wouldn't think so..

Also, correct me if i am wrong, but you can hear a stuck injector when the truck is idling typically right?

 

[Hambone]

Cvs do still spin when driving:thumb:

 

[wilrob]

Cvs do still spin when driving:thumb:

I was on the fence about that one :rofl:

I am trying to figure out how to upload a video

EDIT: https://drive.google.com/file/d/0ByvE_INbxaCwcmhfbnlkUmphQ1VZNmZRMkFDZjlNQVRTQk5N/view?usp=sharing you can hear it in the beginning and end

 

[Pure Diesel]

Now that I'm not sea sick any more from watching the video.

Sounds like a CV.

 

[wilrob]

Now that I'm not sea sick any more from watching the video.

Sounds like a CV.

:roflmao: I never claimed the video would win any Oscars. Thats what I have been leaning towards too, they have been letting go of grease for a while, I just have been a bad owner. That would explain the pop when it goes into gear too

 

[wilrob]

I know DMAX store stuff has mixed reviews, but the entire CV shaft assembly is 100 bucks with a lifetime warranty. Anyone have reviews on these? or am I better off walking into O'reillys?

 

[Hambone]

Our hog truck is making that same noise! :hug:
It’s the Cv... check your wheel bearings while you are there though
Now I’m curious what previous rod knock you have heard to compare it to lol
That’s more of a clunking
Rod knock sounds more like a skeleton jacking off on a tin roof:roflmao:

 

[wilrob]

Our hog truck is making that same noise! :hug:
It’s the Cv... check your wheel bearings while you are there though
Now I’m curious what previous rod knock you have heard to compare it to lol
That’s more of a clunking
Rod knock sounds more like a skeleton jacking off on a tin roof:roflmao:

305 small block, I think I was comparing how they both tend to chase RPM. The old Chevy definitely had more of a ping to it. Looks like I'll be doing a little parking garage wrenching this weekend.

and now I have to get that image out of my head

 

[wilrob]

Replaced the CV shafts, hardest part was getting the dust cover off... she is back to normal now, no noise!

Thanks for the internet diagnosis people!