Recently I had a thread about Lean Codes - Trying to fix them, I put in remanufactured injectors. One of them failed (stuck open), and caused my motor to hydrolock.

Fortunately, the circumstances were favorable and no internal damage to the motor was done. Lucky I guess...

The starter however sounded awful, like one of the gears had been damaged. I replaced it.

Since the hydrolocking, on start up I get a slight clicking noise after the starter turns over and the motor cranks. It was not there before.

I also now have a tapping or rattle coming from the bell-housing area. It’s barely audible in the cabin, imperceptible from under the hood, and obvious from under the truck. It’s consistent any time the motor is running. Not noticeable over 2,000 rpm or so.

In most gears around 3,000 rpm the motor will seem to hesitate - no SES, it’s not a misfire. It feels like the driveline. This has been consistent since the hydrolocking incident.

Am I correct in assuming that instead of bending a connecting rod, when the motor hydrolocked the planetary gear broke on the starter which in turn damaged or cracked the flywheel?

It must have required too much torque to turn over the motor so the gear on the starter gave out instead of turning the motor over?

It seems to me like every thing spelled out above is a symptom of a cracked or damaged flywheels to me.

I’ve put almost 1,500 miles on the truck since and other that the drive hesitation and very slight tapping noise it runs well.

As usual, your thoughts and input are appreciated!

 

Hard to believe the flywheel got damaged, pretty darn stout. Plus, starter gear would be disengaged once engine is running...so...don't know how it could be making noise while running. Does the noise change when you go from reverse to drive? Maybe a cracked flex-plate? Strange noises can be difficult to track down on a running engine, noise transmits through block easily. You could have bent a push rod. At least you know which injector was bad, so checking push rods for that cylinder is easily done.

If you are still concerned about it being the flywheel, pull starter and rotate engine, inspecting teeth as you go. You could throw a dial-indicator in there and check for run-out also.

Good luck.

 

It is a really subtle noise, I have not noticed if it changes from D to R, but will pay attention today. I’ll get a video of it today as well.

Seems like broken flex plates are not unheard of.

I won’t rule out something motor related. I would just think noise from a push rod would be more noticeable in the engine bay. It’s the #3 cylinder that hydro locked so fairly close to the front of the motor.

The noise is really only clearly noticeable if you get under the truck.

It is a light tapping sound. Not a click or a knock. I’ll report back with video.

 

Noise does not change shifting from Drive to Reverse.

 

I called my mechanic and explained this noise, and as the usual voice of reason he said:

“Dude, your truck has always made that noise. I’m not worried about it. If it gets louder, call me.”

Haven’t fully closed the loop on this, but he knows me and my tendencies. If he says it’s been there, then I believe him. I might be overthinking it.

 

I think I might be a bit paranoid. The noise is barely perceptible in the video. It’s a faint tapping sound when I crawl under the truck.

 

Does it tap stone cold? Have you checked the oil pressure?

 

It does tap when it’s cold. More noticeably than once it warms up.

Have not checked oil pressure but probably a good thing to do.

 

Running Rotella T4 15/40.

 

Our freshly rebuilt 04 hated Rotella T4 15W40...had similar noise right after changing, dropped oil immediately and bought some, believe it or not, Carquest, on sale 10W40...and it was like night and day. I'd used the Carquest as a break-in oil, dropped it after 500 miles, added T4...and didn't even get it backed out of the garage...l was like...what the heck is that noise! Changed it back to 10W40...nothing. Yeah, weird. Our 03 loves T4, quiet as a mouse.