BMW 340

Digest from the reviews

Based on transcripts of 2 reviews

• •Both of the 2 reviewed transcripts call the N-series petrols the E90's main expense: both single out the 2.5 six (N52B25) for oil consumption through the piston rings, and the 4-cylinders (N43/N45/N46) are called short-lived and overcomplicated.
• •The safe petrol pick per both reviewers is the 3.0 six: one (АВТО ПЛЮС) calls the N52B30 the least problematic of the whole series and 'an excellent choice' (~30% of used ads), the other notes the 3.0 handles oil far better than the 2.5.
• •Both stress the N-engines tolerate zero overheating: flush the cooling system regularly (one reviewer: yearly, with radiators removed), and budget for valve stem seals — the two transcripts put their life at roughly 60-100k km; one adds the dash has no coolant temperature gauge at all.
• •Both name the N47 2.0d timing chain (rear-mounted) as the headline diesel risk: one reviewer cites a chain snapping as early as 50k km and ~150k km life after replacement; both say the older cast-iron M47/M57 diesels are far tougher — 'a benchmark of reliability' next to the new ones.
• •The ZF 6HP automatic is called sturdy in both reviews (200-300k km before overhaul, repairs well mastered); both also flag the E90-specific battery-positive cable fault — corroding/melting connections can kill the fuse box or cut power entirely, so check it before buying.