a broken chain causes many damaged valves

[shogun]

My friend Ralph (Herbie01) in Germany recently updated his homepage about his E32 740.
A lot of pics. Among others a fridge in the rear between the seats, special thick anti theft window glass, instead of the econometer he installed an oil temperature indicator for engine oil and many other things.
Have a special look under "Kettenriss" = broken chain, where you can see many pics of bended valves and the engine apart. Chain broke at 184 k km
http://people.freenet.de/Herbie01/

[mamilapon]

How common is that ****?

[632 Regal]

very common if you dont follow maintenance replacement.

How common is that ****?

[myles]

I don't recall ever seeing a replacement schedule for the timing chain. What's recommended?

[Rob]

That's what happened to my car. Cam belt snapped while driving. This was when my Dad owned the car. He had the engine re done though. Cost him R15,000 to do.

[GoldenOne]

yeah, that happened to my friends e34 m50 about a week ago, decapitated the engine and found some cool looking valves





all twelve exhaust valves were toast but the intakes are fine...

[mamilapon]

OK guys, lets get it right. There is a replacement schedule for a timing BELT but no replacement schedule (that i know of) for the timing CHAIN.

[mamilapon]

Regal, as far as i know you dont have to replace the CHAINS on yours, correct?

[genphreak]

OK guys, lets get it right. There is a replacement schedule for a timing BELT but no replacement schedule (that i know of) for the timing CHAIN.

One does the chain when one does a short or long engine rebuild - ie head replacement or piston and ring job.

It lasts past the head rebuild point (can be as late as 500k km), but you risk damage if you don't change it then. The drive cogs tend to wear, and one changes the chain with the cogs as they do wear together. Nick

[yaofeng]

OK guys, lets get it right. There is a replacement schedule for a timing BELT but no replacement schedule (that i know of) for the timing CHAIN.

The timing chain is NOT a maintanance item. It lasts the life of the engine. Do you think this ever needs to be replaced? Heck, no.