LVDell

I've got a buddy that broke his timing chain on his low mileage MY99. No mechanical overruns or other abuse.

What do we know about the likely causes of this?

Is the timing chain and supporting hardware a possible known weakness of MY99?

TIA!

GreggT

Of MY99?
Not really..........I think it would be on the general list for M96....not high on the list, but there......(and long after 99).
The 'supporting hardware' on 997s is significantly beefed up.....and when he replaces his engine now, he will benefit from those improvements

cdodkin

Dell, you sure the chains didn't just come off after the end of the intermediate shaft came off?

That's a 'more likely' failure on a MY99

99firehawk

usually the chains break due to something getting between the gears and the chain some thing else likley failed and debris got caught in the chain.
Not to common but i have seen it

LVDell

Not quite sure the specifics of it. Just asking the question for a friend that will read this thread but not as a member of the site. Just doing a favor for him.

Thanks for the input everybody. I am sure you have helped him tremendously.

Tippy

Isnt there 3 of them? 1 from the crank to the intermediate shaft and then 2 from the intermediate shaft to the cams? Which one let go?

99firehawk

actualy on a 99 there are 5 chains
crank to ims
ims to cam x2
cam to cam x2

most likely is one fo the ims to cam chains

Nicolaasdb

i only know it was a weakness in BMW 3 series...needed to exchange it every 30K miles...once I didn't and it snapped at 40K miles.....lucky for in I was standing still...the mechanic told me your pistons will push thru your engine