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Timing belt

Posted: Wed May 11, 2022 5:51 pm
by PaulSanders
Garage has told me that the timing belt has possibly jumped. No symptoms just wouldnt start. Any advice?

Timing belt

Posted: Wed May 11, 2022 6:03 pm
by X5Sport
EDIT - just seen your other post. All the BMWs I know of have timing chains. In a diesel that’s often fatal because the piston can strike the valves as there isn’t much room in the head. Have they run diagnostics, or do you have the car unseen by a garage? Chains don’t tend to jump, they tend to snap and the engine would sound odd when cranking due to compression not being right. Jumping generally only happens if the tensioner fails and that can be heard as the engine starts rattling.

There are a number of issues with fuel or engine electrics that can cause a no-start. Any warning messages? If it’s a non-BMW garage then they need to run full diagnostics to track the issue down. Getting to the timing chain won’t be cheap. If it has slipped/snapped expect serious repair bills unless you have been really lucky with where everything stopped.

Timing belt

Posted: Wed May 11, 2022 8:47 pm
by Leslie
Likely a chain on the 2 litre and they are famous for stretching and breaking tensioners often before 100k was it rattling before?
Codes would help tell if its a timing issue as the chain is possibly at the back of the engine and hard to access. Without gearbox or engine removal
Cylinder Head will need to come off as valves are quite likely will be bent although sometimes just rockers are broken.

Timing belt

Posted: Wed May 11, 2022 9:10 pm
by PaulSanders
No engine rattling or symptoms before it failed to start. No warning messages.
The garage are going to try and replace the sensor first.

Timing belt

Posted: Wed May 11, 2022 9:12 pm
by PaulSanders
The engine turned over when I pushed the stop/start button. Just didn't start.

Timing belt

Posted: Wed May 11, 2022 9:16 pm
by PaulSanders
The engine is an N47 engine. I have read on the internet these engines had timing belt issues.

Timing belt

Posted: Thu May 12, 2022 6:17 am
by Alan Gunn
They have a chain not a belt.
Yes the N47 does have the chain problem but the engine would rattle before it snapped.
A fault code scan before replacing any parts is recommended every time.

Timing belt

Posted: Thu May 12, 2022 8:21 pm
by StuBeeDoo
If, as you say, it drove fine but wouldn't start next time you wanted to use it my money's on the crankshaft sensor.