E70 Xdrive35i Timing Chain Guides...worn out at 95k?

[Longj582]

Hi Guys,

Searched the forums but didn't spot a relevant thread on this (sorry if I missed it).

My always garaged west-coast proactively maintained X5 w/95k seems to have just dropped the top part of the timing chain guide (discovered when the indie who is replacing the serp belt system and VCG "found" it in the bottom of the skid plate.)

Anyway the chain is tight and the part he found isnt the part that actually comes on contact with the chain. (He did say that one of his techs might've broken it...he can't say for certain). Attached are pics he sent me.

He is asking if I want to replace all guides but despite doing guides on older BMWs especially the v8s...he said it's my call as it's a big repair...he also said he's only heard of them going bad on an e70 i6.

His concern is the the part that broke (which again doesnt come in contact with the chain) is "brittle like a potato chip"...so the other guides may be too.

Question: is something y'all have encountered in the 2012 Xdrive35i's? Off all of the BMW higher mileage (e53 and e46) cars with the inline 6...I've not encountered this.

Thoughts? I appreciate the help!

[smassey321]

His tech broke it. If you are rushing a valve cover removal, that part can get hit by the valve cover. That plastic part is sealed inside the valve cover so there is no way for it to end up in the belly pan unless the valve cover area is opened up. The plastic is slightly brittle with age but any good mechanic will know that and be careful.

That part does not go bad. There are plenty of 200k mile I6 BMWs on their original timing chain hardware. It does not wear out on a properly maintained engine.

A complete new timing chain/guide is not required. The broken part is $45. He will need to remove the sprocket to be able to remove and replace. Special tools are needed to hold the camshafts in time. If he does not have these tools, he is not a BMW specialist.
https://www.ecstuning.com/b-genuine-...l/11317592850/

Here is amateur that broke theirs doing a vc gasket. https://www.e90post.com/forums/showthread.php?t=1566915

[ard]

Originally Posted by Longj582

(He did say that one of his techs might've broken it...he can't say for certain).

Kudos to the shop for manning up


Id trust smassey's opinion....