Service 04 of 11
Engine repair
Not every engine fault calls for a full rebuild. A head gasket, oil consumption, coolant loss or a single damaged bearing can often be dealt with directly — provided the cause is established before anything is replaced.
The scope is fixed only after the diagnosis, on Porsche as much as on Audi, BMW and Mercedes-Benz.
Symptoms
When a repair is due
Coolant loss, white smoke
The expansion tank empties with no visible leak, and the exhaust steams even with the engine warm. Often the head gasket; on a diesel, also a leaking EGR cooler.
Oil in the coolant
Brown, oily sludge or an oil film in the expansion tank: oil and coolant are mixing — usually the head gasket or the oil cooler. Do not drive on.
Oil consumption
More than it used to, with no drips under the car: piston rings, valve stem seals, guides — or the crankcase ventilation, and on a turbo engine the turbocharger. The tests show which.
Knocking, falling oil pressure
A bearing failure in the crank assembly. Do not drive on: caught early, crankshaft and crankcase are often spared — driven on, it becomes a rebuild.
The chain has jumped or snapped
Often valves have then met pistons. Head off, valves and pistons checked, chain drive renewed as a set.
Not sure what it is?
Twelve seconds of video of the engine running, plus the fault code and mileage — that is usually enough for a first assessment.
Send a video
Scope
What we repair
Repair means putting right the one fault that has been established, without stripping the whole engine. The diagnosis shows which of these jobs are needed.
- Fault memory, compression and leak-down tests, borescope
- Head gasket, chosen by measured piston protrusion on diesels, with new head bolts where specified
- Head checked for flatness and cracks, skimmed where needed and permitted
- Valves, guides and stem seals on the removed head
- Pistons and piston rings, where the bores are within limits
- Bearing failure: bearings renewed as a set, crankshaft measured and reground if needed, oil circuit cleaned of debris
- Chain drive renewed as a set after a jumped or snapped chain
- Valve timing with locking tools, test run and road test
Makes
Engines we do this on
Give us the engine code — with it we look up the tolerances before the car arrives.
- Porsche
- Flat-six engines, air- and water-cooled – heads and seals; once bearings or pistons are involved, it usually becomes a rebuild
- BMW
- N47 · N47S · N57 – after a jumped or snapped chain
- Audi · Mercedes-Benz
- By engine code
Method
Four steps
- 01
Diagnosis
Fault memory, compression, leak-down, borescope, oil and coolant. The cause first, then the scope.
- 02
Approval
Scope and cost in writing, labour and parts separately. If a repair will not be enough, we say so beforehand.
- 03
Repair
Put right the fault that was found, renew seals and wearing parts as a set, fasteners to torque and, where specified, to angle.
- 04
Handover
Oil pressure and leak checks, warm-up, road test. What was fitted is set out on the invoice.
Questions about it
What people ask about engine repairs
Repair or rebuild — what decides it?
The diagnosis. If the measurements show a single fault in an otherwise healthy engine, a targeted repair is enough. If bores, crankshaft or crankcase are affected too, it would be patchwork — and we tell you so before money goes into half a solution. The decision is yours.
Is it worth it on a high-mileage engine?
That depends on the engine, not the odometer: mileage alone says little about condition, the measurements a great deal. Where the statutory warranty is limited on high-mileage units, we raise it beforehand and put it in writing.
What does the repair cost on an N47 or N57?
If the chain has already jumped or snapped, the price depends on what it damaged — and only the strip-down report shows that. So we quote it on request, with the scope it covers. If the damage goes further, we give you the extra work and its cost first — none of it is done without your approval. The chain job itself is on the prices page, with its price.
Engine repair
Not every fault needs
a new engine.
Related
Related services
- 01
Engine and gearbox rebuilds
When the diagnosis shows more than a single fault.
- 05
Cylinder head and valvetrain
Head gasket, valves, guides — reworked on the removed head.
- 03
Timing chain replacement
Changed in time, before a rattle becomes engine damage.