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Discussion Starter #1
Okay, I know everyone's in a flurry over rod bearings, and I am afraid that is the cause of this scary sound that showed up last week--but my logic seems to indicate it is not (but if it is, I am not wasting any time remedying it).

It is a ticking sound, which is what everyone here mentions for rod bearings. My mechanic says that rod bearings would be more of a thud and thinks it is a VANOS issue and recommended an immediate oil and filter change and then another change again in 2,500 miles to work grime out of the VANOS gears. He works on tons of BMWs regularly, so I know he is smart, educated, and experienced, but I don't believe he has worked on the E39 M5 before mine, so he may not be familiar with the ins and outs of the S62 as many of you are.

I changed the oil and filter per his prescription, but the sound is still present, and I am frightened to keep driving this thing for another 3,000 miles on only one man's advice. The thing that makes me think it may -not- be rod bearings is that the sound manifests itself right around 2,100 RPMs and then goes away as I move up the band. My guess was perhaps the chain tensioner, but I am far from qualified to be making any mechanical diagnoses.

Sound files submitted for your kind and much-appreciated analysis:

Initial cold start of engine and idle--recorded from the cabin and then next to driver's front wheel and then a walk to the front
http://dl.dropbox.com/u/75984167/STE-008.mp3

Gradual revving of engine, highlighting the sounds @ 2100 RPM--recorded from next to the coolant overflow tank (right rear quadrant of hood)
http://dl.dropbox.com/u/75984167/STE-009.mp3

Same procedure repeated, only recorded with lower gain
http://dl.dropbox.com/u/75984167/STE-010.mp3
 

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I'm no expert,but I'm with you on the cam chain.

I think rods would knock all the time.

:dunno:
 

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I would also say chain tensioner. It could be the guides also. Replace chain tensioner and if the noise stays or does not completely go, remove the lower oil pan and look for bits of the plastic chain guides in the bottom of the pan.
 

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Have you eliminated lifter tap as the culprit? If the car sits for long periods of time w/o turnover (3 days+), you can get some pretty wicked lifter noise temporarily (first 15-20min of run-in following cold start).
 

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Discussion Starter #7
Thanks for the replies all. No, I have not done the chain tensioner yet, but that is quite the relief to hear. I am at around 139k, so I am definitely on guard for the bearings issue, and I didn't want to take a chance and be extremely sorry. Also, come to think of it, I am sorely overdue for replacing this item anyway if my memory serves me correctly.

I, in my limited capacity, really doubt it's VANOS (though that quick oil-change procedure doesn't hurt anyway); it just doesn't seem right to me, but what the heck do I know.

The car is a daily driver, so I don't think there's a chance for the lifter problem you describe, QuickSilv3r -- also [according to my mechanic] the noise is not coming from anywhere where it would be lifters.

Now can you guys please tell me how to do the tensioner replacement?

j/k, I already DAFS, plus I'm sending this one out.
 

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Yikes! Definitely sounds like chain slap either from worn plastic guides or possibly slapping the aluminum valve covers. I'd get that remidied asap before it eats away any additional parts/material. Tensioner first, but also do as Sailor24 mentions, pull that lower pan anyway to inspect for pieces. Good luck!
 

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Yikes! Definitely sounds like chain slap either from worn plastic guides or possibly slapping the aluminum valve covers. I'd get that remidied asap before it eats away any additional parts/material. Tensioner first, but also do as Sailor24 mentions, pull that lower pan anyway to inspect for pieces. Good luck!
 

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Discussion Starter #12
OP here, and I feel like I want to cry. Had my mechanic replace my chain tensioner last week, but there was still considerable slack in the chain. He reached out to some other techs to try to remedy the problem after ruling out anything in the valve area. They too suggested dropping the oil pan. Supposedly there is a guide in the front of the engine that is probably shot....like a ramp the chain rides on is way out of spec.

He is going to drop the oil pan on Monday and check it out with a fiber optic scope, but if that is the case -- I am told -- it will require the engine out, which at that point means having other stuff checked too. He estimates a minimum of 50 hours of work, taking about 4-5 weeks (he's already had it for 1).

I just can't imagine shelling out another $8,000 for this car after the thousands I've put in the past 24 months. Also, it really isn't a good time to be buying a new car. Can someone show me a sign or at least have some words of encouragement lol?
 

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It is way easier than that, don't get ripped off by your mechanic making it sound harder than it is. You drop the pan and look to see if there are chunks of plastic. There will be and you decide to do the chain guides. This can be a DIY project it is not rocket science. Search chain guides there are a bunch of posts. The engine does not need to come out.
Your mechanic is either BSin you or does not know what he is doing. Print one of the DIY threads and ask him why he can't do it as good as an average non mechanic guy?
 

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Holy hell, engine out? I would consult with Raiiku(VantaaM5) first on that point as I *thought* I remember reading or seeing where you can replace that front guide mechanism with the motor in the bay. I could be wrong though. Either way, I empathize with you. Sometimes **** happens and makes M5 ownership hard to swallow or enjoy when they usually are pretty reliable for the most part. Good luck!
 

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Discussion Starter #17
Thanks fellas, I so hope you are correct. I feel like he knows, and yet he does not know. He's worked on BMW and Mercedes pretty much exclusively for his career, but does not seem to have any M experience. This is only my second major repair by him, so I can't necessarily attest to his work yet either. See my much earlier post in this thread about him thinking that my chain was a VANOS issue initially, something which I, my uneducated self, disagreed.

Unfortunately I neither have the knowledge, the means, nor the confidence to do the job myself. I will do as you have suggested and present him with a DIY thread on Monday and see what he says. I think I mentioned above that he questioned a few other techs online to get their advice about the chain slap post tensioner replacement (the response to which I've been waiting for all week from him) before coming to the aforementioned conclusion.

I was really hoping this would be my go-to guy, but I guess that remains to be seen.

Using the DIY method, what would you estimate my repair cost to be just out of curiosity.
 

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You can see the chain guides in this photo. There is the long one each side of the cam chain and the v-shaped one in the middle. The thin plastic "liner" on the v-shaped one and the one on the left gets brittle and breaks up and then the chain wears into the aluminum casting. (The one on the right is solid plastic and I haven't heard of that failing.).
As you can see, I replaced them with the engine in the car. Maybe show your guy this photo and ask him (politely) why he wants to take the engine out. He may have decided or been told that if the chain has been wearing into the aluminum then aluminum particles will have been circulating round in the oil and the brgs, cylinders, pistons, etc. will be worn. There is a drop of truth in that. The rod brgs on these engines seem to be a bit prone to wear and would be sensitive to this contamination. But they can also be changed with the engine in the car.

Best to ask him exactly what he plans on doing.

Good luck.

PICT0750.JPG
 

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With the cost of repairs compared to value of an M5 you really need to start doing repairs yourself. This board is a huge help and the more you do the more confidant you will become. I strongly urge that you find a buddy to help you tackle this project and allow board members(much more knowledge than your mechanic) to help you through it.
 
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