EXPERT IN AUTO PARTS
24 November 2025 (updated) Table of Contents
The timing chain of the BMW E90 shows frequent defects, especially in the popular engine variants 320i 170 hp and 318i 143 hp. These weak points typically manifest themselves between 80,000 and 120,000 kilometres through characteristic rattling at cold start, loss of power and uneven engine running. The symptoms often intensify in cold temperatures and can lead to serious engine damage if they are ignored. It becomes particularly critical when the timing chain no longer jumps correctly and the engine does not shift properly. The service life of the timing chain is highly dependent on the quality of maintenance and driving conditions, with frequent short journeys exacerbating the problem.
Regular maintenance is crucial for the early detection of timing chain problems. The precise BMW E90 timing chain systems require special attention during inspection, and noise, engine smoothness and fault memory should be checked regularly. Replacement of the complete timing chain, including tensioner and guide rails, is usually necessary between 100,000-150,000 km and should be carried out as a preventive measure to avoid costly consequential damage.
The air conditioning system in the BMW E90 has considerable reliability problems, which are particularly evident in the 318i 129 hp and 320i 150 hp engine variants. Frequent complaints occur as early as 60,000 kilometres, with the air conditioning system no longer working properly or not starting. Typical symptoms are a lack of cooling capacity, unusual noises from the compressor or complete failure of the cooling system. The breakdowns are often caused by defective air conditioning compressors, leaking condensers or blocked expansion valves. Particularly problematic is that the air conditioning system does not switch between different modes or shows faults in the electronic control.
A systematic check is essential for diagnosing air conditioning problems. The complex BMW E90 air conditioning systems require regular servicing every 2-3 years, including refrigerant top-up and filter change. A professional inspection can prevent expensive repairs and ensure the optimal functioning of the air conditioning system over the entire life of the vehicle.
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BOSCH Mass air flow sensor
Article number: 0 281 002 757
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BOSCH Mass air flow sensor
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GARRETT Turbocharger
Exhaust Turbocharger, VTG turbocharger, pressure/vacuum-controlled divert-air valve, Diesel, Euro 4, Incl. Gasket Set
Article number: 724930-9010S
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GARRETT Turbocharger
Exhaust Turbocharger, VTG turbocharger, pressure/vacuum-controlled divert-air valve, Euro 5, Vacuum-controlled
Article number: 785448-5005S
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The rear window regulators of the BMW E90 show typical weak points that are characterised by frequent defects and reliability problems. These problems usually occur between 50,000 and 80,000 kilometres and are manifested by jamming mechanics, slow window movement or complete failure. The symptoms often begin gradually with grinding noises and end with the windows no longer closing or opening completely. It becomes particularly problematic in winter when the window regulators stop working due to damp and cold. Breakdowns are mainly caused by wear and tear on the window regulator motors, defective guide rails or broken Bowden cables.
A professional inspection is required to correctly diagnose the window regulator problems. The mechanically stressed BMW E90 window regulator systems require regular lubrication of the guide rails and inspection of the electrical connections every 30,000-40,000 kilometres. Preventive maintenance can significantly extend the service life and avoid expensive repairs to the entire window regulator unit.
The windscreen washer system of the BMW E90 regularly causes complaints and shows frequent defects that can significantly impair driving safety. These weak points typically occur between 40,000 and 70,000 kilometres and manifest themselves as a lack of washer fluid supply, clogged nozzles or complete pump failure. The symptoms range from a weak water jet to complete failure of the system, whereby the windscreen washer system no longer functions reliably. It becomes particularly critical when the pump does not start or the nozzles are completely blocked, resulting in visual obstructions. Reliability suffers from frost, dirt deposits and inferior cleaning agents.
Professional maintenance is crucial for the proper functioning of the windscreen washer system. The BMW E90 windscreen washer systems require regular cleaning of the nozzles and checking of the pump function every 15,000-20,000 km, especially before the winter period. The use of high-quality windscreen cleaners and additives suitable for frost protection can significantly extend the service life of the system and avoid costly repairs.
The boot of the BMW E90 has various technical defects, which are particularly noticeable at higher mileages. Frequent problems occur from 60,000-90,000 kilometres and mainly affect the electric boot opening, defective gas struts and locking mechanism faults. The symptoms are characterised by sluggish opening, automatic slamming or complete failure of the electric operation. It is particularly annoying when the boot does not pop open or does not switch properly. Breakdowns are often caused by worn hinges, defective microswitches or problems with the central locking system. The reliability of the boot system depends heavily on maintenance and care.
Regular maintenance is essential for the boot to function properly. The BMW E90 boot systems require regular lubrication of the hinges and inspection of the electrical components every 25,000-30,000 km. A professional inspection can detect signs of wear at an early stage and significantly extend the service life of the mechanical and electrical components.
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GARRETT Turbocharger
Exhaust Turbocharger, VTG turbocharger, pressure/vacuum-controlled divert-air valve, Diesel, Euro 4
Article number: 717858-5010S
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GARRETT Turbocharger
Exhaust Turbocharger, VTG turbocharger, pressure/vacuum-controlled divert-air valve, Diesel, Euro 3
Article number: 717858-9010S
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VARTA Battery
12V 80Ah 740A Lead-acid battery
Article number: 5804000743132
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Article number: EL1050
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Article number: EK820
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Based on the experience of BMW E90 owners, the following additional problems occur:
| Strengths and weaknesses | Weak points |
|---|---|
| High-quality workmanship | Timing chain problems |
| Sporty driving dynamics | Air conditioning failures |
| Comfortable equipment | Window regulator defects |
| Good engine range | Windscreen washer system defects |
| Stable body value | High repair costs |
| Precise steering | Electronic faults |
| Solid safety equipment | Boot problems |
The BMW E90 proves to be a fundamentally high-quality vehicle with excellent driving characteristics, but it requires regular and cost-intensive maintenance. The most common problems can be dealt with by preventive measures and professional maintenance, whereby the timing chain, air conditioning system and electrical components in particular deserve special attention. Despite the known weak points, the E90 remains a popular model for drivers who value driving dynamics and comfort.
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