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Problems with oil leaks: symptoms, cost and affected models

We have documented 27 faults with oil leaks in 23 engines, affecting 113 models of car in our database. The most important by severity and frequency: oil cooler seal leak (between the cylinder heads) (OM642), N63 oil consumption from worn valve stem seals (BMW N62 / N63) and oil leak from the timing chain cover (1.6 dCi). At an independent garage, the repair costs from €200 to €2,200 depending on the engine or car.[1][2][3]

Documented faults
27
6 of high or critical severity
Engines
23
with at least one fault on this part
Affected models
113
car generations in our database
Garage repair
€200–€2,200
Depending on engine and car, including VAT

3 sourcesHow we work

How it works and why it fails

Oil leaks

Oil leaks usually come from gaskets and seals that harden with heat and age: the rocker cover, the sump, the filter housing or the oil cooler. More than the oil loss itself, the risk is that it drips onto the exhaust or that the level drops without you noticing.

What to do

Look for stains on the garage floor and traces of oil around the engine. A small leak can wait until the next service, but if it drips onto the exhaust (smell of burning or smoke under the bonnet) or the level drops quickly, take it to a workshop as soon as possible.

General explanation by MotorFiable. The specific faults of each engine and car, with their sources, are on the linked pages.

Common symptoms

The symptoms that come up most often in the documented faults with oil leaks. Open each one to see what other faults cause it.

Problems with oil leaks by engine

From most to least important (severity × frequency). Each page details the affected versions and years, symptoms, cost and how to check for it.

  1. 1High severityVery frequentFrequency: Very frequentOM642Oil cooler seal leak (between the cylinder heads)Yes: the OM642's oil cooler, between the two cylinder heads, has seals that harden with heat and eventually leak oil. It is the engine's most frequently cited weak point, especially before 2009-2010, and the repair is expensive because the intake manifold, turbo and several injectors have to be removed.Repair (garage): €1,500–€2,200Appears at around 120,000 km
  2. 2High severityCommonFrequency: CommonBMW N62 / N63N63 oil consumption from worn valve stem sealsYes: the original N63 is known for using oil and the German press attributes it to worn valve stem seals. Gebrauchtwagenberater gives €3,000-4,500 as a repair reference in Germany.
  3. 3High severityOccasionalFrequency: Occasional1.6 dCiOil leak from the timing chain coverThe 1.6 dCi uses a timing chain, not a belt, but several Kadjar and Espace V owners describe oil leaks around the chain cover or casing, in some cases serious enough to require removing part of the engine.
  4. 4High severityOccasionalFrequency: OccasionalVolvo 5 cilindros gasolinaFront camshaft seal leak wetting the timing beltWith the crankcase ventilation blocked, the pressure can force the front camshaft seal and the oil reaches the timing belt. It is a serious risk, because if the belt fails the valves bend, but the sources give no case figures.
  5. 5Medium severityCommonFrequency: CommonBMW B58Oil and coolant leak from the plastic oil filter housingThe B58's plastic oil filter housing can crack or lose its seal with heat and age, letting oil, coolant or both escape. One parts retailer puts the failure between 60,000 and 100,000 miles (roughly 97,000-161,000 km).Appears at around 97,000 km
  6. 6Medium severityCommonFrequency: CommonBMW B58Failure of the crankcase ventilation PCV valve (integrated in the valve cover)On the first-generation B58 the PCV valve, integrated in the valve cover, can tear its diaphragm and stop separating oil from the crankcase gases. It causes blue or white smoke, a whistling noise, higher oil consumption and misfires; the whole cover is usually replaced.
  7. 7Medium severityCommonFrequency: CommonBMW B58Oil leak from the valve cover gasketThe rubber gasket on the B58's valve cover hardens with heat cycles and eventually leaks oil: a burning smell, smoke near the cover and oil on the spark plugs. Guides place it between 60,000 and 100,000 miles (97,000-161,000 km).Appears at around 97,000 km
  8. 8Medium severityCommonFrequency: CommonBMW M54Oil leak from the valve cover gasketThe M54's valve cover is made of plastic and, over the years, warps and stops sealing: oil leaks, a burning smell, oily spark plugs and misfires appear. It is replaced together with the gasket.
  9. 9Medium severityCommonFrequency: CommonBMW N20Oil leaks from the rocker cover gasket and the filter housingYes: with the years and heat cycles, the rocker cover gasket and the oil filter housing or cooler gasket on the N20 start to weep oil; it is not an acute defect but expected wear that is worth watching before the oil level drops too low.
  10. 10Medium severityCommonFrequency: CommonBMW N43/N46Oil leaks and consumption (rocker cover, vacuum pump and valve stem seals)Over the years, the rocker cover gasket and the brake servo vacuum pump gasket start to seep oil on the N43 and N46; on the N46 there are also the valve stem seals, which can cause more noticeable oil consumption than on the N43.
  11. 11Medium severityCommonFrequency: CommonBMW N52 / N53Oil leak from the oil filter housing gasketThe oil filter housing gasket hardens over time and leaks oil on all N52 engines; the leak can soil the engine and damage nearby parts.
  12. 12Medium severityCommonFrequency: CommonBMW N54/N55Oil leak from the oil filter housing gasketThe oil filter housing gasket on the N54 and N55 leaks oil as it ages; the oil can drip onto the auxiliary drive belt, and there are also leaks from the valve cover.
  13. 13Medium severityCommonFrequency: CommonM111Camshaft adjuster oil leak into the wiringYes: the magnet (solenoid valve) of the M111 camshaft adjuster can lose its seal, and the oil creeps up by capillary action to the connector and the wiring loom. Mercedes-Benz has the same repair cable as for the M271 (part number A2711502733), which is cheap to fit.
  14. 14Medium severityCommonFrequency: CommonM271Oil leaking from the camshaft adjuster solenoids into the wiringYes: the camshaft adjuster solenoids (magnets) of the M271 can lose their seal, and the oil wicks up to the connector and the wiring loom, and can even reach the control unit. Mercedes-Benz has a specific repair cable (reference A2711502733) that is cheap to fit.
  15. 15Medium severityCommonFrequency: CommonM270/M274Oil leaking from the camshaft adjuster into the electrical connector (M274)Yes: on the M274, the camshaft adjuster solenoids can lose their seal over the years and let oil wick up to the connector and the wiring harness, potentially reaching the ECU. It is fixed relatively cheaply with a specific repair cable.
  16. 16Medium severityCommonFrequency: Common1.0/1.2/1.4 EcotecOil leaks and increased consumptionOn the Corsa C, D and E, the Astra H and the Meriva, oil leaks from the rocker cover, oil filter or pressure switch are common, along with somewhat higher than normal oil consumption between changes; there is no pattern of major engine damage if they are dealt with in time.Appears at around 80,000 km
  17. 17Critical severityRareFrequency: RareBMW M47Oil leak from the brake vacuum pumpA BMW specialist workshop documents that the seals of the M47's vacuum pump, which generates the vacuum needed for brake assistance because a diesel does not produce it naturally, can wear and let oil through, which can end up stiffening the brake pedal.
  18. 18Medium severityOccasionalFrequency: Occasional2.2 JTDm Multijet IIEngine oil leaksLeaks and oil consumption are the most cited items in testimonials for the 2.2 diesel: 12 of 84 in the Stelvio and 9 of 68 in the Giulia. A 100,000 km test detected a fluid loss around the crankshaft; Alfa Romeo replied that the measured wear was low.
  19. 19Medium severityOccasionalFrequency: OccasionalBMW B48 / B38Oil leaks or seepage from seals and covers, near the turbo and the VANOSYes: over time, oil seepage or leaks can appear at seals, covers and crankcase ventilation connections, in an area of the engine close to the turbo and the VANOS system.
  20. 20Medium severityOccasionalFrequency: OccasionalBMW N62 / N63N62 blue smoke and oil consumption from hardened valve stem sealsOn the N62 V8, the valve stem seals can harden with age and cause oil consumption with blue smoke. It is not a widespread fault: several German guides describe the engine as solid.
  21. 21Medium severityOccasionalFrequency: OccasionalM272/M273Oil leaks from the cooler, separator and camshaft adjuster gasketsAgeing M272/M273 engines can leak oil from the oil cooler gaskets, the separator, the camshaft adjuster connectors and the plastic cylinder head covers.
  22. 22Medium severityOccasionalFrequency: OccasionalPorsche V8 and V6 (Cayenne and Panamera)Oil leaks from rocker cover gaskets and engine sealsStuttcars considers oil leaks relatively common on the Panamera V8 engines (rocker cover, camshaft housing and filter housing) and CarWiki cites the crankshaft seal, sump and valve stem seals on the 3.6 V6 and 4.8 V8. More than 300 ml per 1,000 km is considered suspect.
  23. 23High severityRareFrequency: RareM264/M254Oil leak at the turbo oil line connections (fire risk)In 2020 Mercedes-Benz recalled the four-cylinder petrol engines built from March 2018 to March 2020 (C-Class 205, E-Class 213 and 238, S-Class 222, GLC 253, CLS 257): the tightening of the turbo oil lines had not been documented and, if they were not properly tightened, they could drip onto hot parts.
  24. 24Low severityCommonFrequency: CommonBMW N52 / N53Valve cover and crankcase ventilation valveThe N52's plastic valve cover cracks with heat cycles and the crankcase ventilation system fails, causing whistling, leaks and oil consumption.Repair (garage): €200–€350
  25. 25Low severityCommonFrequency: CommonM112 / M113Oil leaks from the valve cover gaskets and the breather coverYes: oil leaks from the valve cover gaskets and from the crankcase breather cover are the most cited problem on these engines. Several sources describe them as common with age, and English Wikipedia places them on the M112 from around 170,000 km.
  26. 26Low severityCommonFrequency: Common1.4 and 1.6 TU3/TU5Oil leak from the rocker cover gasketThe rocker cover gasket dries out with the years and lets oil seep into the spark plug wells: besides the oil stain on the engine, it can soak the spark plugs or the ignition module and cause misfires.Appears at around 120,000 km
  27. 27Low severityOccasionalFrequency: Occasional1.2 8v FireOil consumption or leak, in one case from the rocker cover gasketThe 1.2 8v Fire can start to use or lose oil after a certain mileage; the only case with an identified origin points to the rocker cover gasket. It is the issue that recurs most for this engine, always in a minority of cases and without damaging the block.

Engines with faults with oil leaks

Problems with oil leaks by make

Problems with oil leaks in your car

43 cars have several documented faults with oil leaks. Choose yours to see only the ones that affect them, by engine and by year.

BMW 26
Mercedes-Benz 16
Toyota 1

How much it costs to repair a fault with oil leaks

Sorted from the most expensive repair to the cheapest. Prices in Spain including VAT (parts and labour); what each figure includes is on its page.

How we calculate costs · The most expensive repairs across all engines

OBD fault codes with oil leaks

The codes the ECU usually stores when this part fails: what they mean, causes and what to check.

Frequently asked questions

Which engines have the most faults with oil leaks?

By severity and frequency, the OM642 (oil cooler seal leak (between the cylinder heads), high severity), the BMW N62 / N63 (N63 oil consumption from worn valve stem seals, high severity), the 1.6 dCi (oil leak from the timing chain cover, high severity), the Volvo 5 cilindros gasolina (front camshaft seal leak wetting the timing belt, high severity), the BMW B58 (oil and coolant leak from the plastic oil filter housing, medium severity) and the BMW N52 / N53 (oil leak from the oil filter housing gasket, medium severity). In total we have documented 23 engines with faults with oil leaks.

How much does it cost to repair a fault with oil leaks?

It depends a lot on the engine or car. At an independent garage, from €200 to €2,200; at a dealer, from €2,500 to €3,500, including VAT, based on the 2 faults with a documented cost. The most expensive is oil cooler seal leak (between the cylinder heads) (OM642).

What symptoms does a fault with oil leaks cause?

The most frequently cited in the documented faults: visible oil leak, excessive oil consumption, burning smell, bluish smoke from the exhaust, engine fault warning light (check engine) and oil mixed with the coolant.

Sources

Every fact on this page links to its source. If you find an error, let us know.

  1. 1.Problemas BMW N52Total Renting · Other source · consulted 5 October 2026 · in Spanish
  2. 2.Mercedes OM642 : fiabilité, pannes fréquentes et coûts d'entretienAutoCopilot · Motoring press · published 2026 · consulted 26 September 2026 · in French
  3. 3.Mercedes OM642: Zuverlässiger Dauerläufer oder Kostenfalle?Gebrauchtwagenberater · Motoring press · consulted 26 September 2026 · in German