When/cost to change timing chain E36?

[yosshimura]

I was looking through a Bentley's today at the bookstore and saw the maze of the timing chain. When are these required/suggested to be changed (I would rather not deal with a broken chain inside the motor )? Looking at the manual, it looks like a PIA (PITA ). How much would a shop charge to do the job or how many hours are on the book for this mission?

This is certainly not as easy as changing the timing chain on my GM cars .

[Mickey]

PIA?

Oh! PITA! (Church Lady voice Never mind :-)

[bimmer95]

Originally posted by yosshimura
When are these required/suggested to be changed (I would rather not deal with a broken chain inside the motor )?

There is no replacement schedule for timing chains, they should last the lifetime of the engine. Generally you only need to replace a timing chain when the motor is torn down for a complete rebuild.... maybe after 200k+ miles.

[yosshimura]

Bimmer95, that sounds too good to be true : . Is this what BMW or Bentley's recommends ? (didn't see anything on maintainance schedule in the Benltey's.

I am bringing it up b/c the Mercedes on their M103 I-6 it is recommended to take a look at them / replace at about 100K, but those are fairly easy........

I guess, I am trying to find worse case scenarios (as in alot of $) on maintainance issues I will need to deal with sooner or later. You know water pump, radiator, fuel pump, timing chain, heads / valves (when do those need maintainance?), etc.

water pump, radiator, fuel pump are pretty simple...

thanks:

[ms318is]

My opinion is the same as Bimmer95.
Chain technology has really advanced, and a well designed sprocket/chain system using high quality materials (which GM chose not to use for many years) will last for a very long time.
Sharing what I have learned in my motorcycles, which all have chain drive DOHC:
- Chain breakage is almost unheard of in normal use.
- The normal reason for replacement is stretching. As the chain stretches, it will affect cam timing. In motorcycles, it retards the timing, hurting midrange power.
- Motorcycles are FAR more abusive to the cam chain, as they rev much higher (10K+ rpm) and they have much less flywheel, so the rotatational acceleration rates are much greater, which applies much greater stress.
- Most motorcycles are NOT engineered to last 200K+ miles like our BMW's so they will be a weaker system
- Even so, it is rare for a motorcycle cam chain to require changing before 50K miles. My ZG 1000 is at 80K and shows very little stretch.

Putting all that together, I conclude there should be no need to worry about our BMW chains for, oh, about 500K miles or so!

Valves? Same thing. Modern valve seat and valve metrology allows these to last almost indefinitely if not abused.

Use good fuel, good oil changed regularly, don't run her at redline all the time, don't race the engine when cold, and you should be fine for at least 200K, if not 500K miles.