Help diagnosing a ticking/knocking noise

[nitrousflame]

*See video link at the bottom of this post*

About a month ago, my car started developing a ticking noise. At first, it was a just a ticking noise and seemed to have no affect on performance. The ticking got louder and faster with higher rpms. I did a lot of searching on here and thought it might be a lifter, but the ticking didn't go away as the engine warmed up, but rather it made very little noise on a cold start and got louder as the engine warmed up. I added an oil thickener -- no change. Changed oil -- no change. Changed timing chain/gears/tensioner -- really no change, except for after a while, I could here more of a "knock" along with the tick.

As it stands, on cold start, there are a few ticks right as it starts, then they go away and the engine sounds normal. As the car warms up, the ticking/knocking becomes much more prevalent. After a while of driving (maybe 10+ miles) there is a noticeable drop in acceleration off the line. It's almost as if there is a governor (perhaps knock sensor kicking in to retard timing?)

Finally, I brought the car to a transmission shop to have a look at it (I've also been experiencing hard shifts between 1-2 and 2-3 every once in a while, but it goes back to normal if I turn off the car and then back on again. Related issue?) and the transmission shop said they saw the torque converter move in and out when they stepped on the gas. they recommended I look for a new engine. :p

1999 Camaro 3.8
A little over 70,000 mi
4L60E
Stock accept I removed the air silencer and MAF screen and there is some aftermarket muffler (not sure what it is, it was on the car when I got it)

I should also mention that I've listened to the engine with a stethoscope and was not able to pinpoint the noise. It sounded like it was coming from everywhere. Also, way back when it first started, I took the serpentine belt off and the tick still didn't go away.

Here is a video I took yesterday of the noise to give you an idea. You can hear the knock at idle and as the rpms go up, you can hear the tick come in as well.

http://www.youtube.com/watch?v=1OwvI...e=channel_page

I'm out of ideas. Any suggestions at this point would be awesome.

[3.4grapeofwrath]

Re: Help diagnosing a ticking/knocking noise

Recently I had the same problem as you it ended up being a cracked flexplate.
I had the car on jackstands and with the cover removed I could hear the ticking noise coming from the torque converter area. Remove your torque converter cover then remove the outer bolts holding the torque converter to the flexplate and slide the torque converter into the tranny to see better. Check for fine cracks around the inner bolt pattern of the flexplate. Mine was very hard to see. The ticking seem to come and go at times then finally it got to the point where it was always there. If it is your plate that is cracked there not to expensive around $70 and can be installed without removing the tranny.

[nitrousflame]

Re: Help diagnosing a ticking/knocking noise

Recently I had the same problem as you it ended up being a cracked flexplate.
I had the car on jackstands and with the cover removed I could hear the ticking noise coming from the torque converter area. Remove your torque converter cover then remove the outer bolts holding the torque converter to the flexplate and slide the torque converter into the tranny to see better. Check for fine cracks around the inner bolt pattern of the flexplate. Mine was very hard to see. The ticking seem to come and go at times then finally it got to the point where it was always there. If it is your plate that is cracked there not to expensive around $70 and can be installed without removing the tranny.

Thanks for the reply. Would a cracked flexplate cause the torque converter to move in and out when you step on the gas? I was thinking my problem might also be a thrust bearing. Could this be?

What is the source of the tick/knock with a cracked flex plate?

Thanks again.

[cam98aro]

Re: Help diagnosing a ticking/knocking noise

iam almost positive it is one of these three things:

1. cracked flexplate like mentioned above
2. bad balancer
3. bad bearing

[nitrousflame]

Re: Help diagnosing a ticking/knocking noise

iam almost positive it is one of these three things:

1. cracked flexplate like mentioned above
2. bad balancer
3. bad bearing

Thanks for the response.

What bearing are you referring to? Thrust bearing?

[94Firebird34]

Re: Help diagnosing a ticking/knocking noise

Rod and or Crank bearings the sound is a bit too deep to be a flexplate or Balancer I have been wrong before but it does really sound like a rod or crank bearing.

[cam98aro]

Re: Help diagnosing a ticking/knocking noise

Rod and or Crank bearings the sound is a bit too deep to be a flexplate or Balancer I have been wrong before but it does really sound like a rod or crank bearing.

yup, i agree

i gave the other options since it i cheaper to check the flexplate/balancer out than it is to see if the engine needs new bearings

[3.4grapeofwrath]

Re: Help diagnosing a ticking/knocking noise

I just got a chance to listen to the video you posted. That's no ticking noise that is a knock for sure. Check your outside flexplate bolts that hold the torque converter to the flexplate they may have come loose. My sister's car had the same problem it sounded just like that.

[nitrousflame]

Re: Help diagnosing a ticking/knocking noise

I just got a chance to listen to the video you posted. That's no ticking noise that is a knock for sure. Check your outside flexplate bolts that hold the torque converter to the flexplate they may have come loose. My sister's car had the same problem it sounded just like that.

It is indeed a knock, but there is also a ticking noise that comes in when I rev it up a little bit. It's hard to hear the tick in the video though since the knock is overpowering the tick.

Sounds like it's narrowed down to either bearing or flexplate so I guess I'll just have to take a closer look at the flexplate and if it doesn't look like that, just go ahead and replace the bearings.

I'll be sure to report back what I find.

[nitrousflame]

Re: Help diagnosing a ticking/knocking noise

I disconnected the transmission and looked at the flexplate and it looks fine. Disconnected the torque converter/flexplate from the engine and started it up.

The knock is still there.

So I guess that narrows it down to bearings. Will I need to take the engine out? What's the best way to do so?

Thanks again.

[flamingchicken]

Re: Help diagnosing a ticking/knocking noise

thats a rod knock for sure. bad rod bearing, im 99% sure.

you will more than likely need a rebuild...

[ssms5411]

Re: Help diagnosing a ticking/knocking noise

Mine sounded like that when my balancer dry rotted on the inside out. I would check that before tearing into the engine. Its common on l36's and l67's. Just check behind the balancer to see if it has rotted off, to make the crank off balance.

[nitrousflame]

Re: Help diagnosing a ticking/knocking noise

Mine sounded like that when my balancer dry rotted on the inside out. I would check that before tearing into the engine. Its common on l36's and l67's. Just check behind the balancer to see if it has rotted off, to make the crank off balance.

I had my balancer off when I replaced the timing chain/gears and didn't notice anything rotted off, but then again I didn't pay too close attention to it either. What exactly rots off on it?

Thanks.

[ssms5411]

Re: Help diagnosing a ticking/knocking noise

The rubber part dry rotts and chunks will come off throwing the crank off balance.

[flamingchicken]

Re: Help diagnosing a ticking/knocking noise

The rubber part dry rotts and chunks will come off throwing the crank off balance.

watch the video, he has the later balancer. it only has a think little thing of rubber on it.