[thecarfarm]

Yes, so the long story short goes something like this...

Bought a 2007 335i sedan at salvage auction. The car had a very light front end hit. Brought the car back to our shop, got it running and put it all back together. The car was running and driving fine. And with only 7000 miles on the car we were psyched at the price we paid. Now we drove the car quite a bit in NY then sent it up to Canada for export sales. While at BMW in Canada, the car had the retrofits for miles to kilometers and whatnot done by BMW. OK...they test drive the car "extensively" to clear all codes, etc so that it will pass Canadian emissions, etc...OK... we send one of our guys out to pick up the car when it is done...OK... he happily drives away...OK.... about 5 miles down the road the crank bolt falls out and bends all the exhaust valves...WTF?!?

So there is the ugly story. BMW of course offered to put a new engine in the car for around $20,000. How nice of them.

So my question here, based on some things that I've seen in other forums, is whether or not anyone has ever heard of this sort of crank bolt problem or not. I had found a forum post a few weeks ago where the exact same thing happened to another individual but now I've lost the link. I've also heard tales of some timing chain tensioner problems that can cause the crank bolt to back out. Anyone ever hear of such madness? At any rate. That's the story in a nutshell. Any info anyone has would be helpful. According to a friend of mine at BMW, they have seen this before and told me that they wouldn't be surprised to see a technical service bulletin pop up soon.

Cheers

[scalbert]

You sure you are not talking about a cam retainer or similar? There is no real way anything attached to the crank could ever touch the valves.

[thecarfarm]

No, the actual crank bolt that holds the crank pulley came loose and fell out...along with about half the oil. BMW says that it must have skipped timing and bent the exhaust valves.

[scalbert]

Originally Posted by thecarfarm

No the actual crank bolt that hold the crank pulley came loose and fell out...along with about half the oil. BMW says that it must have skipped timing and bent the exhaust valves.

Now I understand. And yes, that can destroy a head, engine depending on what happened witht eh pistons when they slapped the valves.

That shoudl not happen on its own. But this was picked up from a salvage so the impact was pretty hard.

Have a private shop pull the head and check the pistons. You might get away with just a rebuilt or new head.

[thecarfarm]

Unfortunately already had BMW pull them and check. They say the valves are bent. But there was zero evidence of any damage to the engine from the accident. I've posted some photos of damage prior to repair for anyone's interest.

[scalbert]

So, the dealer won't just replace the head?

[thecarfarm]

Salvage title automatically voids dealer warranty unfortunately...and conveniently for them.

Really a shame because even the techs and service managers at the BMW service center are completely confounded by it. They don't see any evidence of how this could have been caused by the accident. There are absolutely no marks on the engine or pulleys at all. In addition, they said that if the bolt was loose or somehow the crank had become bent because of the accident, there would have been a check engine light indicating a problem from the crank angle sensor or the sensor on the viscous coupling on the crank end. And they had cleared every single code on the car with road testing prior to giving it the clean bill of health to drive off.

So they seem as bummed as we are. They're not happy certifying a car road worthy and ready to go and then have the engine go south 5 miles down the road. Never looks good for them.

[Jeff@Eurobahn.us]

Something is very very fishy going on here. The amount of toque used to install that pulley is sufficient to withstand an impact to the front end that you showed in your photos. Also if the pulley was damaged it would have felt very funny as the engine would not have been properly balanced and the engine would have shaken!

I would be very very suspicious!

Jeff
Eurobahn

[thecarfarm]

I am suspicious...that's why I'm trying to dig deeper into this. I can understand BMW not wanting to warranty a salvage vehicle, and I would never want to try to have warranty work done if I thought it had anything at all to do with the accident but I personally had the car running and driving in New York and saw absolutely no evidence of any shaking or vibration. I not only had the car idling for a good while to bleed the coolant system when I filled it but took it out for some slow test drives followed by some more spirited test drives to make sure everything was in good working order before it was shipped up north. Combine that with the BMW dealership in Canada telling me that they drove the car "extensively" and I'm left with what definitely could be called suspicion of a flaw from the factory. As I mentioned, even the techs are suspicious. They don't think it's from the accident either. But after many fruitless discussions with BMW I'm kind of screwed unless I can find some other documented instances of this to try and petition BMW to address this as a service issue or possible recall. As I mentioned earlier, I had found a post on a different forum about a week ago where someone else had a problem with their crank bolt coming loose but foolishly did not bookmark it.

But yes, I smell a rat somewhere. And no, that light front end collision should not have done any damage to the engine. Nor is there any sign of damage. If anyone is familiar with how vehicles get salvaged, it's all pretty much up to the insurance adjuster. The car had every single airbag deployed (so new dash was needed!), cracked windshield, clock spring, sensors, rear seatbelt tensioners, blow off cable, bumper cover, damage to both lights, grill, fog lights, etc, etc. With paint and all the insurance company wrote up a repair estimate of over $16,000 on the car. Yes, crazy prices but then again, the dash alone is around $900 on the car. And they had no mention of any engine damage in the insurance write up.

Ah well...thanks for the feeback so far. Will keep hunting for that elusive link.

[darkphantom]

engine mounts anyone?

[Joeyballs]

Sorry for your misfortune man. Hopefully theres a less expensive alternative.

[thecarfarm]

So the head of service at my local dealership says that he has seen this happen before. According to him, the crank bolt can back out if the engine is over-revved. WOW! Hooray for BMW engineering.

So of course now I'm wondering if my guy who picked up the car was doing smoke shows and donuts or what?

He said he was pulling away from a red light slowly. Yeah, probably slow compared to the Lamborghini next to him he was drag racing says I.

But that aside, I've been trying to get a hold of a regional service rep from BMW to see if I can't lodge a complaint with the top brass at BMW. I call corporate headquarters in New Jersey. The customer service rep there tells me that they do not have the numbers for the regional service reps since they are always on the road and that I should contact my local dealer to get that information. OK. So I call my local dealership back where I've spent countless thousands and have a very good repoir. The usual friendly reception is given until I ask for the regional service reps number. My generally friendly BMW buddies turn into robots at that point and say ,"I'm sorry sir but we are not at liberty to disclose that information." Whoa! I had to laugh. So as I'm laughing, I ask if there is any way that this information can be obtained. "NO". So there is no way of going higher up the ladder on these complaints unless you write it in...in triplicate...where it will be filed under "radioactive waste"...in a locked basement room...somewhere in Poland...guarded by a leopard.

Thanks for the customer service BMW! You can take your free Starbucks and BMW chocolate bars and shove 'em!

Ah, well. Ordered a used engine with a one year parts and labor warranty. The beast will live again!

[BavarianBullet]

Wow. That officially MEGA-sucks.

Based on what you said it sounds like the single large harmonic balancer retaining bolt backed out while driving which flung the harmonic balancer and, unfortunately, the time chain drive cog as well.

Not all engines will bend valves if a timing chain/belt drive breaks but if you lose a harmonic balancer, depending on how the engine is designed, that could have easily destroyed the lower half of the engine (main bearings, caps, hairline cracks, etc).

If the HB flung, I'd say you definitely did the right thing in not trying to repair the engine or head. That could have been a different nightmare.

I'm also extremely surprised, as most are, that this bolt could have come out. A front-end impact would have next to nothing to do to with this. It sounds like a build defect in the engine or balancer or weird engine harmonic of some sort.

I've done a bit of drag racing back in the 90s and a particular company that makes aftermarket harmonic balancers got a bad reputation because some people that used their HBs and they ended up coming off the cars during races. Not cool to see your engine go boom and it was clearly something odd with the balancer because the stock HBs never did it.

Scary. Makes me want to put some locktite goop on my balancer bolt but WTF, it's a lease.

[Orient330iNYC]

i dont think 16K of damage on a 335i is enough to total it out....
thats not even 40% of the market value of a stripped one.

most insurance companies wont total untill about 70-80%

[sd390r]

time for an INSURANCE SCHEME