Nosie coming from engine or transmision

[nick2020]

Hi,

Looking for some help. I have a 6.9 manual 4 speed with a noise coming from the engine or maybe clutch area? I can only hear the noise when the truck is in idle, it does not go away if I engage or disengage the clutch. It does go away as soon as I get going in first or second gear. No sure how to describe the noise other that a bit of spin grind. The truck reads 54,000 miles but this 1984 has to have way more. It starts up right away. Also I has a banks turbo, I can't hear the turbo but I can feel it if I put my hand on it when on idle. Should I be able to here it?

Thanks in advance. My mechanic skill level is minimum but getting better.

 

[IDIBRONCO]

If you have an open exhaust and/or fairly open intake, then you should be able to hear the turbo at an idle. Otherwise, maybe not. Don't get too shook up about the noise that the turbo makes. The situations vary. The particular model of turbo that you have on your truck may make a big difference as well (Banks offered three different turbo kits for our trucks). I've even known a guy who had a 95 PSD that was running terribly. It started out with a slight miss (when another guy owned it) and by the time that he got rid of it, it had to been running only on 7 or fewer cylinders. He just knew that the turbo was bad because when he drove up hills, he couldn't hear it as loudly as he used to. I didn't even bother trying to explain drive pressures, cylinder pressures, and turbo noises to him. He wouldn't have understood even if he had believed me.

 

[Big Bart]

Nick2020,

Perhaps take two videos and post for us.

Put your camera on the ground under the middle of your truck where your bell housing is. Start the truck and wait say 15 seconds. (Guessing it makes the sound all the time.) Then engage and disengage the clutch say 5 times. Then put in and out of 1st gear say 3 times. Then drive off. Then post.

Then put the camera under the hood and face it towards the turbo. Then start the truck in neutral with the clutch out. Run it at idle for 15 seconds, then run it up to 1,500 rpms for 10 seconds, and then up to 2,000 rpms for 5 seconds. The move the camera so we can see the front of the engine and repeat. Then post.

So could be multiple things since you say it is a grinding sound. But without some idea of what the sound is like, hard to say.

Some thoughts.

1) If its coming from the bell housing or tranny.
a) Your pilot bearing or clutch perhaps is worn out. A bad throw out bearings generally sounds different when in neutral VS when your clutch is depressed. A worn out clutch could be grinding rivits on the flywheel.
b) Perhaps you input shaft or other bearing inside the tranny is bad. Once the truck gets moving or locked to another gear it smooths out. But when idling in neutral and not turning any gears, it makes a grinding sound.

2) If it's your turbo
a) It would make sense you do not hear it, but rather a grinding noise if the bearings are bad.
b) It would perhaps center up or make less noise when spinning fast. (From a grinding noise to a light hum.)

I also wonder if your starter is not retracting and spinning till you take off. Or if it is rubbing against the flex plate till you take off. However this generally would not come back after the starter retracted and the noise went away.

Once we all can see and hear we can get you more narrowed in on the possible issue.

 

[nick2020]

Thank guys, I'll take vide and post as soon as I can