Service 03 of 11
Timing chain replacement
A stretched timing chain announces itself with rattling on a cold start and with faults in the camshaft adjustment. Drive on with it and you risk the engine. We renew chains, tensioners, guide rails and sprockets as a set, and reset the valve timing.
On the BMW N47 and N57 the chain drive sits on the gearbox side. The job is correspondingly involved — and routine for us.
Prices
What it costs
Per engine, for the scope described. Click your car to see what the job covers — and every other price for it.
Porsche
BMW
Mercedes-Benz
All prices incl. VAT.
Symptoms
How you notice a stretched chain
Rattling on a cold start
One or two seconds of metallic rattle after starting, which disappears once oil pressure builds.
Camshaft adjustment faults
Stored fault codes for camshaft and crankshaft position, often together with limp mode.
Rough running, lost power
The valve timing is out; the engine runs rough, picks up poorly and drinks more.
Debris in the oil or filter
Wear from guide rails and sprockets ends up in the oil circuit — a reason to stop immediately.
The chain jumps
The worst case: valves meet pistons. From here it is no longer a chain job but an engine repair.
Not sure it is the chain?
Twelve seconds of video of the cold start is usually enough for a first assessment.
Send a video
Scope
What gets replaced
The chain drive is renewed as a set. A new chain on old tensioners and rails will not last — and the job comes round a second time.
- Timing chain and, where fitted, the oil pump chain
- Chain tensioners and guide rails
- Sprockets on crankshaft and camshaft
- Gaskets and oil seals as a set
- Valve timing set with the specified locking tools
- Oil change afterwards, test run and road test
Engines
Engines we know this job on
The engine codes we renew the chain drive on.
- BMW
- N47 · N47S · N57 – chain drive on the gearbox side; the engine stays in, on the N57 the gearbox comes out
- Audi
- EA888 · 3.0 TDI
- Mercedes-Benz
- OM651 · OM642 · M271 · M274
- Porsche
- 911 · Boxster · Cayman · Cayenne · Panamera · Macan
Method
Four steps
- 01
Inspect
Fault memory, cold-start noise, chain stretch measured via camshaft position.
- 02
Approval
Scope and cost in writing, labour and parts separately. No part without your yes.
- 03
Replace
Renew the chain drive as a set, set valve timing with locking tools, reseal.
- 04
Handover
Oil change, test run, road test, the parts fitted documented on the invoice.
Questions about it
What people ask about chain jobs
Does the engine really have to come out on a BMW N47?
No. On the N47 and N57 the chain drive does sit on the gearbox side, but the engine stays in the car for the chain job. On the N57 the gearbox has to come out completely. That is why the job on these engines is more involved than on a front-mounted chain drive — the price per engine is on the prices page.
Can I keep driving if it rattles?
Better not. If the chain jumps, valves meet pistons, and a chain job becomes an engine repair. If the noise is new, call before you do the next long run.
Do I get genuine parts?
In the chain drive we fit genuine parts, or parts from the relevant original-equipment supplier. Where there is a sensible alternative we put both options in front of you with the price and the difference, and you decide. What was fitted is then set out on the invoice.
Timing chain replacement
Rattling on a cold start?
Then now, not next month.
Related
Related services
- 04
Engine repair
When the chain has jumped and valves have met pistons.
- 05
Cylinder head and valvetrain
Valves, guides and seats checked and reworked on the removed head.
- 06
Engine oil service
Mandatory after a chain job — and where debris shows up first.