conflicting views

[stegosaurus]

So I just recently purchased a 91 318is with 150k on it. I have complete maintenance records and they don't show any work having been done on the timing chain, the PO confirmed this as well. I've heard that the timing chain needs to be done at 100k, but my mechanic says that it's not something I need to worry about for a while, saying he's seen over 250k on an m42 with the original timing belt. I don't believe it but I don't have any other references. I'd appreciate some help/advice. I'm quoted at $2100 for the whole timing chain and cooling system work if I wanted it done; I've found some DIY articles on timing chain replacements, and also articles on cooling system work, I also know my way around cars pretty well and I have mechanic friends; however, I feel like I would be taking a shot in the dark trying to do the work myself. Should I believe my mechanic and let it go until it hits 250k? even 200k? Should I try to do it myself? Should I get it done by the mechanic who doesn't think I need it done?

[Petebee]

If you do it yourself parts would be in the neighborhood of $600-$700. It's really not that difficult. I would recommend the cam locking/flywheel locking tools to keep everything in place.

Search in the Engines forum, several posts about this.

[stegosaurus]

Thanks for the quick reply. I'll do a search for it.