Random tick - Silverado 4.8

[bigmike]

Changed my oil last weekend and noticed I have a random ticking/clicking noise but only after the engine is warmed up.

I doubt it has anything to do with the oil change, but rather I'm now noticing it because I was listening for any noise afterward (force of habit, I guess).

The tick is definitely coming from the bottom end, either from the engine or transmission. Could be an exhaust leak, I'm guessing, as well.

It's not really loud. I can hear it at idle only. No driveability issues to report of so far.

Just for the record:
Transmission is a GM reman unit with only 13k miles on it. Dealer installed it and haven't had any problems to report from it since. I have a magnefine filter on the return, since it was installed after the last A/T grenaded itself.

Engine is a 4.8 V8 with 61k miles. It is not neglected.
Oil out: Pennzoil Conventional 10w30 and Bosch filter
Oil in: Quaker State 5w30 with Napa Gold filter




I've read about the parking pawl or torque converter could be a problem. Also, drive shaft splines. Exhaust leak comes to mind. I read a few TSBs on engine ticks, but those were mostly for piston slap and diesels. Doesn't feel or sound like a u-joint.

I doubt it is from the engine, because it really purrs like a sewing machine and has since I bought it.


I know we have some excellent GM guys on here.
Any suggestions?

 

[229]

Flex-Plate crack.

 

[bigmike]

I forgot some really important information!

It only happens in gear, drive or reverse. It doesn't go away in reverse or drive. In Park, I can't hear anything unusual. Neutral seems for the noise to take longer to go away, but it does go away.

The clowns that put the transmission in didn't bother to put 2 of my engine block bolts back in either (driver's side). Noticed that last night.

Sorry for that!

 

[229]

The dowels HAVE to be reinstalled!
Like I said, I am fairly certain this is your problem.

 

[RF Overlord]

Originally Posted By: bigmike
I've read about the parking pawl Also, drive shaft splines. Doesn't feel or sound like a u-joint. Any suggestions?
You said this only happens at idle...none of those things are rotating when the car isn't moving.

Or did I not read your post correctly?

 

[bigmike]

Originally Posted By: RF Overlord
Originally Posted By: bigmike
I've read about the parking pawl Also, drive shaft splines. Doesn't feel or sound like a u-joint. Any suggestions?
You said this only happens at idle...none of those things are rotating when the car isn't moving.

Or did I not read your post correctly?


Only at idle in gear. I can't hear it or feel it when driving.

 

[bigmike]

Originally Posted By: 229
Flex-Plate crack.


Very well could be. I can look in the inspection hole and see if I see anything. Plan on crawling under it tomorrow.

 

[ARCOgraphite]

+2 on the flex plate damage on a bungeled re-install - or loose bolts on the plate or Tconverter.

 

[afoulk]

Seems to only be when you put a load on the engine. If thats the case, I'd be looking at the flexplate bolts, torque converter bolts, or the flex plate itself as well.

 

[Hokiefyd]

It does sound like the flexplate is cracked.