2020 x1 sdrive SE 2.0d - timing chaing and flywheel issue?

[jlc450]

Hi there,

I need advice.

I have replaced timing chain and flywheel. My mechanic tells me that one of the bolt hole for timing chain tensioner guide is cracked [see photo], and that the dual mass flywheel has not been fitted correct previously, hence it is slightly bent/ or wrongly positioned or something like that. Are these a big issue? I dont notice anythng when driving.

 

 

[Greydog]

Hi John

Welcome to the Forum

You say "you" replaced the Timing Chain and Flywheel? The crack in the mounting will depend on whether the correct torque can be achieved ? If it can on a test tightening I would be inclined to use some thread loc and go with it. Otherwise repairs would mean a complete strip down or even a block.

The Flywheel I am confused if it wasn't fitted flush with the crank boss previously there would be serious vibrations at certain revs surely? Did you replace the flywheel with a dual mass unit?

Is the mechanic in there because of issues?

Dave

[jlc450_2]

Hi Dave,

 

Firstly, with regards to the dual mass flywheel, I don't notice any vibration at certain revs nor when changing gears. This is the thing. When my mechanic changed the timing chain, he simply pointed this out.

With regards to the bolt hole, I don't know if held the correct torque for tightening. All i know is that new timing chain kit is now fitted.

Let's says the worse case scenario happens and that bolt loosens up - would there be a sign? Like a noisy/whiney engine?

[Greydog]

Morning John

As the bolt is part of the chain tensioner system I would assume if it loosens you would get chain slap at start up and rattle/noise of some sort. 

If the guy you used is a reasonable mechanic then I would think that it has been torqued correctly so no reason for it to come loose new bolts have thread loc applied.

I have never worked on the N47 engine however as the Timing chain is at the rear of the engine I know with BMW Main Dealers it's an engine out job, so I would think Fly wheel off as well to access the chain. So if the fly wheel was not seated correctly before it sounds as though he has corrected it. Being dual mass it has a bonded rubber section to remove vibration and noise it may be the rubber had been deformed previously?

If it's running well Drive it and enjoy it

Dave