Okay, so after tons of searching, reading and video watching I wanted to post my issue and see if I could get some help in correctly diagnosing.

I have a ticking/knocking sound that is audible immediately at start up and gets much louder and more squeakier at higher rpm (no check engine light). Checked oil and it was a little low. It took half a quart to bring it up to full. It sounded like it was coming from the valve train so I pulled the valve cover removed the rocker arms and found one exhaust arm had a cracked plastic retainer. The tension is good on the timing chain and in the last 15K miles I have replaced replaced chain guides and tensioner. So I bought a complete new set of rocker arms, installed and same issue.

Soooo...my question is how can I begin eliminating other issues without just throwing parts at it (as in could be serpentine tensioner, Crank dampener, SC water pump or spun bearing). The car doesn't overheat so I'm thinking it isn't the SC/water pump. The serpentine belt tension does bounce a little but it doesn't seem to overly move and isn't jiggly in any way. Is there a way I can check the Dampener and belt tensioner to eliminate them as issues?

I fear I may have a spun bearing. The video that seems to sound the most similar is this one: Is dropping the oil pan and visually inspecting the only way to know?

Thanks in advanced for any advice and help, it is greatly appreciated.

06 MCS 85K
Thumper Head/NS1 Cam, 15% pulley

 

If it sounds like that video I would agree with the spun bearing. My buddy had a e46 BMW that made the same noise and sure enough spun bearing.

 

did you replace the timing chain guides due to wear and a previously loose chain? I had that issue last fall and replaced the chain and guide. This spring I saw lots of metal shavings on the magnetic cam sensor, was worried, and sure enough, a few months later, spun a bearing, killed the motor. During the repair/swap, found out the block was worthless as a core due to lots of metal missing on the end that had been worn off while the chain was slapping. Our best guess is that the chain was removing material from the block while it was loose, and the metal shavings worked their mischief in the sump, killing the rod end bearings.

Dropping the oil pan and visually inspecting the bearings is a relatively low cost option. If you exhaust other possible sources of the noise, it's a whole lot cheaper to pull the pan and look now than wait and find out you should have later.

 

Yes I replaced the chain when the tensioner failed and destroyed the guides. I dropped the pan when that happened to remove all of the chunks of plastic, there wasn't any metal. The chain did wear on the block very slightly.

Did you have any sign the bearing was going, as in ticking or metal in oil?

 

I was able to upload a video I took last night, taken with an iPhone so not the greatest

http://www.youtube.com/watch?v=ewz92...ature=youtu.be

 

From the sound that im hearing from the last video.. It doesn't sound like a spun bearing to me.. In my experience and from what I can hear here is the sound is coming from the upper part of your engine.. You have more of a taping type noise..not a lower nock noise that you normally would hear from a spun bearing.. Can you trace the sound to one side of the motor or location?

 

To my ear it sounds like it is coming from the passenger side of the vehicle. I thought it sounded like the top end as well but after checking the rocker arms several times and the timing chain having tension I'm not sure what it could be. Ideas? I tried the old screwdriver trick but that didn't really help me localize the sound.

 

How much should the belt tensioner move at idle?

 

Bump

 

Using the holes that stick up as a guide,.. Mine does not move much at idle, but revving the engine will make it squeeze down a little. At idle having someone in the car turn on the AC also makes it bounce a hair. I'm talking about the distance of say 1/2 a hole that it moves, and I'm real sure my damper is shot. My metal-strap-style of tensioner stop vibrates sometimes, especially when engaging the clutch at that initial moment of inertia. I thought it was an exhaust shield at first. I found it was the tensioner stop, and wondered if this was a design flaw. I concluded that I'll change out my tensioner and have a damper that actually works before I blame the stop for being noisy. These little movements that cause the vibration are about a 1/16th inch or less. I think a good damper should firm that up.

Hope that helps. Maybe an expert can comment if the blown damper is the cause if my vibration. So far it's just a theory of mine.

BTW, I have all stock pullies. I replaced the belt with an original size contitech belt. Within a few months it stretched, and I had even more bounce of the tensioner then. I forced a napa JCW size belt on, and it's better now. I didn't realize my sc pulley was slipping a little, until I changed to the smaller belt and discovered a lot more boost by the seat-of-pants-Dyno...and my ear.

 

Mine definitely is moving at idle and the sound is starting to sound squeakier. I tried to take a video to show the movement. It is hard to tell but it is moving.

http://www.youtube.com/watch?v=doCsq...ature=youtu.be

I am thinking my issue may be the tensioner.

 

Look on amazon for a Gates tensioner. It's the same manufacturer that makes the Genuine MINI Brand one, but it's more like $75 ish. The genuine mini one is A LOT more.

 

Yup, I found it. Thanks Alex for that tidbit, I hope this solves the problem.

 

I just replaced the tensioner on my MCS and it cured any/all sounds being created. Gates P/N => 38404.

Works great so far. Good luck!

I think Amazon has the cheapest price.

 

When you have the tensioner off, you might consider replacing the belt at the same time,.. Obviously, -but also be sure to turn the other pulleys by hand, listen for squeaks, and feel for rough spots or loosness worn bearings.

 

So I changed the belt tensioner and belt but the noise is still present and unchanged. I check all the pulleys I could when the belt was off and all seemed fine.

I guess the next likely candidate is the crank pulley. I really don't want to spend money on the pulley, install it and have the noise still be there. I guess I'm going to have it towed. I'm at my wits end. It just doesn't sound like it is coming from the crank pulley.

 

I thought I would update this in the event someone had similar issues and stumbled upon my video links. The final conclusion was it had a bad rod bearing

I am going to install a re manufactured short block. Now I am trying to figure out what all I should replace while the engine is out given my budget.

Ideas?

 

How did you come to this 'final conclusion?' Have you actually removed the pan?

 

Correct or that is what the shop is saying. I am going to check it out first hand on Monday.