BMW E46 N42 engine Timing chain

zippy320

Well-known member
Hi Guys!

How often am I supposed to change the timing chain ? I spoke to a Dealership and they told me that it should be changed every 100 000kms , My cars mileage is now at 233 333 Exactly . The chain was changed at at 120 000 or around there .

Also the new redesigned chain tensioner was used at the time of the change . Should I change this again ? does it loose its tension over time?

Also when changing the chain , what should be changed with it in order to prevent future issues ?

Also , how big of a job is this , to change the chain?

I am getting two faults

2781 Camshaft sensor inlet ( I replaced this with a new one , fault still there )

27BB Camshaft control outlet vanos ( I took this out and cleaned it up )

My fuel consumption has gone up a little , and I noticed a little less low end power , and sometimes the car rattles a bit . But most times not at all . Sometimes it does make a funny noise at startup .

I was told that when these faults occur then it is the timing chain , either it needs to be replaced , the tensioner needs to be replaced or the timing is out .

Thanks guys for all input .

Just an Update , When I did the valve stem seals at SMG , I had asked them about the rails and guides and they told me that its all in good condition , this was last year sometime.
 

rtayob

Member
Old thread. but Im getting the same error codes on my E46 318i. Did you manage to get yours sorted out ?
 

zippy320

Well-known member
Yup , I had a vacuum leak , between the Air filter and the Throttle body , there was a hole made on the side of the airbox duct , Hole was created by a failing Belt which constantly hit the plastic piece causing it to break . This caused my problem.
 

MHN

Member
zippy320 said:
Hi Guys!

How often am I supposed to change the timing chain ? I spoke to a Dealership and they told me that it should be changed every 100 000kms , My cars mileage is now at 233 333 Exactly . The chain was changed at at 120 000 or around there .

Also the new redesigned chain tensioner was used at the time of the change . Should I change this again ? does it loose its tension over time?

Also when changing the chain , what should be changed with it in order to prevent future issues ?

Also , how big of a job is this , to change the chain?

I am getting two faults

2781 Camshaft sensor inlet ( I replaced this with a new one , fault still there )

27BB Camshaft control outlet vanos ( I took this out and cleaned it up )

My fuel consumption has gone up a little , and I noticed a little less low end power , and sometimes the car rattles a bit . But most times not at all . Sometimes it does make a funny noise at startup .

I was told that when these faults occur then it is the timing chain , either it needs to be replaced , the tensioner needs to be replaced or the timing is out .

Thanks guys for all input .

Just an Update , When I did the valve stem seals at SMG , I had asked them about the rails and guides and they told me that its all in good condition , this was last year sometime.

I have the exact same car as you. Same year and engine.
I got mine about 3-4 weeks ago.
The mileage is 139 000 km.

I also get that loud (and scary) noise when I start the car.
My fuel consumption is about 10.5L/ 100km.

I had 2 mechanics look at it. They say the timing chain needs to be replaced.

My primary mechanic must still look at it though. It may only be the tensioner though. I believe that it does lose tension over time.

Also need to do valve stem seals.
 

zippy320

Well-known member
Yup! Do the tensioner , It does wear out over time . If your car still has the old style tensioner change it to the new style as well .

Timing chain , I was told should be replaced every 100k as they stretch , and the guides and rails should also be changed as well cos the plastic gets brittle and breaks . Which can lead to the chain slipping .

I believe that noise we hear is Oil pressure related . Because , even after I had BMW replace the chain , guides etc etc a long time ago , the noise was still there . But that noise only happens when the car sits for some time . Like starting it in the morning .
 
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