BMW M135i service and repair costs
BMW M135i service and repair costs run £280 to £440 for a full service at an independent garage, £180 to £360 for front pads, and £900 to £1,400 for a clutch on manual cars. One complication before any quote makes sense: two completely different cars wear this badge, and they break in different ways.
Two very different cars, one badge
The 2012 to 2016 M135i (F20 shape) is a rear-wheel-drive hatch with a turbocharged 3.0 six-cylinder. The 2019-on M135i xDrive (F40 shape) is a four-wheel-drive hatch with a turbocharged 2.0 four. Same name, different engines, different gearboxes, different faults. Know which one you're pricing up before you compare quotes, because a garage quoting blind off the badge is your first warning sign.
M135i garage prices in full
Fair independent prices, parts and labour included. BMW dealer rates sit well above these; our dealer vs independent guide quantifies it.
| Job | Fair independent price |
|---|---|
| Full service | £280–£440 |
| Interim service | £150–£250 |
| Front brake pads | £180–£360 |
| Front brake discs & pads | £450–£820 |
| Rear brake pads | £140–£280 |
| Rear brake discs & pads | £340–£620 |
| Brake fluid change | £70–£130 |
| Wheel alignment | £80–£180 |
| Clutch replacement | £900–£1,400 |
| Timing chain replacement | £700–£1,250 |
| Spark plugs | £160–£310 |
| Battery replacement | £220–£390 |
| Alternator | £400–£720 |
| Drop links (pair) | £120–£250 |
| Shock absorbers (pair) | £400–£780 |
| Ball joints (pair) | £250–£480 |
| Front wheel bearing | £200–£390 |
| Air-con regas | £60–£120 |
| Diagnostic check | £50–£100 |
| Exhaust section | £260–£600 |
Known faults: the six-cylinder F20
The old six is a gem with three habits. First, the electric water pump fails, often without much warning, and because it's electric rather than belt-driven there's no squeal to tip you off; overheating on a motorway is the classic first symptom. Second, it leaks oil from rubber gaskets as they harden with age: the valve cover gasket and the oil filter housing gasket are the usual suspects, smelt as burning oil before you ever see a drip. Third, ignition coils fail and cause misfires, cheap enough individually that many owners just carry a spare. Add carbon build-up on the intake valves (it's direct injection, so fuel never washes them clean) and a plastic charge pipe that can crack under boost, and you have the complete F20 bingo card. All fixable, none fatal, all cheaper caught early, and a £50 to £100 diagnostic check beats guesswork every time.
Known faults: the four-cylinder F40 xDrive
Newer, so a shorter list. The best-documented is a rattle from the turbo wastegate linkage (the flap controlling boost pressure) on light throttle as the engine warms; BMW has acknowledged play in the linkage, and plenty of dealers call it "within limits", which is cold comfort but genuinely mostly cosmetic noise. Valve cover gasket leaks turn up from around 50,000 to 60,000 miles, and early cars had several recalls, including airbag wiring and brake software, so check the recall history is clear on any used purchase. The four-wheel-drive system has been trouble-free so far. Treat both generations to oil changes every 10,000 miles rather than BMW's longer suggested gaps; it's the single best thing you can do for the timing chain.
Servicing costs through the year
Full service £280 to £440, interim £150 to £250, alternating annually. Spark plugs at £160 to £310 on schedule, brake fluid every two years at £70 to £130. Both engines are chain-driven with no scheduled change; £700 to £1,250 covers a chain if a neglected one ever gets noisy. Alignment at £80 to £180 yearly is worthwhile, pothole season knocks these cars out of true and eats the inside edge of expensive tyres.
Is an M135i expensive to maintain?
It's honest hot-hatch money rather than M-car money. The F20 six costs a little more to fuel and fix than the F40 four, and its age means gaskets and coils are live issues now. Consumables are the steady cost on both: quality tyres, front discs and pads at £450 to £820 when they're genuinely worn, and brakes wear quicker on the heavier xDrive car than owners expect.
Avoiding the badge tax
The M badge invites padding. A water pump on the F20 is a known, routine job, not exploratory surgery, and a wastegate rattle on the F40 doesn't need a new turbo on a stock car. Get the diagnosis itemised, run your reg through our free repair cost checker, and if you suspect you've already overpaid, start with our overcharged guide.
Common questions
What's the difference between the old and new BMW M135i?
The 2012 to 2016 car is rear-wheel drive with a 3.0 six-cylinder turbo; the 2019-on M135i xDrive is four-wheel drive with a 2.0 four-cylinder. They share a badge and little else, and their common faults differ, so always quote and compare repairs against the right generation.
What goes wrong with the six-cylinder M135i?
Three things dominate: the electric water pump failing with little warning, oil leaks from the valve cover and oil filter housing gaskets, and misfiring ignition coils. Carbon build-up on the intake valves and cracked plastic charge pipes also feature. All are well understood and fixable at sensible independent prices.
Is the turbo rattle on the new M135i xDrive serious?
Usually not. Play develops in the wastegate linkage, the flap that controls boost, and it rattles on light throttle while warming up. BMW has acknowledged it, and many dealers class it as within limits. Annoying, yes; a stock car rarely needs the turbo replaced for it.
How much does an M135i service cost?
£280 to £440 for a full service at an independent, £150 to £250 for an interim. Skip BMW's long suggested oil intervals and change it every 10,000 miles; fresh oil is the cheapest protection the timing chain and turbo can buy. Brake fluid is £70 to £130 every two years.
How much is a clutch on a manual M135i?
£900 to £1,400 fitted, and most of that is labour because the gearbox has to come out. Quotes at the top end usually include a new dual mass flywheel, the heavy damped plate the clutch grips. On the six-cylinder cars, that flywheel often does need doing at the same time.