[Bmill160]

If the motor didn't shut off when the smoke appeared (post apocolypse) and there wasn't any noise or warning lights, what are the chances I didn't contact any valves or anything?

[maveric23]

Originally Posted by nnacpil

How is it worse?

http://www.m3forum.net/m3forum/showt...post1065358457

It is my opinion that the cam gear bolt failure is not due to material failure but that they become loose for some reason and this causes the cam gear to grind against the bolt threads. Over time this sawing action leads to the bolts shearing. Why the bolts become loose is the million dollar question. Perhaps it's an improper torque setting on one of the engine builder's torque wrench? That would explain why some engines never experience a bolt failure while others are affected relatively early in their service life.

Bottom line: Inspect for loose cam gear bolts whenever you have the valve cover off. If they are loose, replace them, ideally with the original part number. If they are not loose, leave them intact.

[drunk hal]

Originally Posted by Dirty Elf

You think that wear occurred on tight bolts?

[Firstboost]

Originally Posted by Dirty Elf

Unless you consider replacing the exhaust cam gear hub preventative maintenance, which would be sort of ridiculous, then most of these cases are on cars that the owners perform regular maintenance and are just cruising down the highway with no warning signs when they explode. No amount of preventative maintenance can prepare you for that.

The keyword, which was bolded, underlined and capitalized, was most, not all.

[Dirty Elf]

Originally Posted by drunk hal

You think that wear occurred on tight bolts?

No, no, I wasn't trying to argue with your or your point.. maybe I chose the wrong smiley, sorry about that. Just pointing out that these bolts, new or old, definitely have problems.

Originally Posted by Firstboost

The keyword, which was bolded, underlined and capitalized, was most, not all.

Your point is valid, but doesn't really pertain to the catastrophic vanos failures at all. Most, if not all, of the problems of this nature that I have seen have been to cars that have been well maintained. Obviously the engine is going to be better off with routine maintenance, but even if it is maintained to the teeth, it doesn't seem to prolong or prevent these catastrophic failures.

[Bmill160]

Ok... UPDATE:

We towed it over to Kelly BMW from IPS Motorsports to have the diagnosis done there. We got as far as taking the valve cover off and there is a tooth missing from the cam and broken bits from the tensioner and guide. The IPS techs are fairly certain the chain jumped and the motor lost time which would bend the valves and basically destroy the inside of the motor.

Had some calls with BMWNA and they are waiting on the diagnosis from Kelly so we can "see how they can help." Keeping my fingers crossed at the moment until they tear into it. Hopefully BMW does the right thing. :/ Sure would go a long way down the road when it's time for the next one.

[Dirty Elf]

Originally Posted by Bmill160

Ok... UPDATE:

We towed it over to Kelly BMW from IPS Motorsports to have the diagnosis done there. We got as far as taking the valve cover off and there is a tooth missing from the cam and broken bits from the tensioner and guide. The IPS techs are fairly certain the chain jumped and the motor lost time which would bend the valves and basically destroy the inside of the motor.

Had some calls with BMWNA and they are waiting on the diagnosis from Kelly so we can "see how they can help." Keeping my fingers crossed at the moment until they tear into it. Hopefully BMW does the right thing. :/ Sure would go a long way down the road when it's time for the next one.

extremely interested. whatever you do: TAKE NOTES, WRITE DOWN NAMES, GET ADDRESSES AND PHONE NUMBERS AND EMAIL ADDRESS

good luck to you sir

[drunk hal]

Originally Posted by Dirty Elf

No, no, I wasn't trying to argue with your or your point.. maybe I chose the wrong smiley, sorry about that. Just pointing out that these bolts, new or old, definitely have problems.

Ha, no prob.

[m3new]

sucks dude. Serious design failure...no wonder the e92 didnt have a vanos

[Bmill160]

So there is PLENTY of talk about VANOS failures that result from the tabs breaking off or the cam gear bolts shearing... but how many of these are caught and how many result in a destroyed motor? Anybody have any ideas?