BMW valve cover gasket leak — symptoms, cost, and DIY replacement guide

about 2 months ago· 2 posts

The valve cover gasket is one of the most common oil leaks on BMW engines. Here is how to diagnose and fix it. SYMPTOMS: burning oil smell, oil pooling around spark plug wells causing misfires, visible oil on valve cover edges, oil dripping onto serpentine belt, low oil level, blue smoke from engine bay. AFFECTED ENGINES: N52 (after 80k km), N54/N55 (after 60k km), M54 (after 100k km), N20 (after 50k km — known weak point), B58 (after 80k+ km). DIY GUIDE (N54/N55): Remove engine cover, disconnect coil packs, remove valve cover bolts (22x 10mm — note different lengths), clean surfaces, install new gasket with RTV at half-moon joints, torque to 10 Nm. PARTS: Gasket kit 30-60 EUR, new valve cover if warped 100-200 EUR. Shop cost: 300-600 EUR total.

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Replies (2)

Greg

about 2 months ago#1

Done this job dozens of times. Most important tip: photograph the bolt pattern before removal. The N54/N55 valve cover uses 3 different bolt lengths — putting a long bolt in a short hole can crack the head. Also replace the eccentric shaft sensor seal (N52) or VANOS solenoid O-rings (N54/N55) while the cover is off. For the N20, BMW released an updated valve cover (11 12 8 645 888) that fixes the chronic leaking — about 180 EUR but solves it permanently.

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Sam

about 1 month ago#2

Just did this on my E90 325i N52 as my first major DIY job. Took about 4 hours. Hardest part was cleaning old gasket residue — use a plastic scraper and brake cleaner, never metal on aluminum. Total cost 45 EUR vs 450 EUR shop quote. Also check the PCV valve while the cover is off — on the N52 it is integrated into the valve cover. If stuck open, it causes excessive oil consumption. New valve cover with PCV is about 150 EUR and solves both problems.

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