Field notes · 17 BMWs & Porsches · E28 to 991

Old BMWs and Porsches, kept on the road.

What breaks, what it costs to fix, the torque spec, and where to buy the part. Written for anyone with a floor jack and a free Saturday.

Common searches VANOS IMS bearing Cooling system Timing belt

Line drawing of a Porsche 911 (964) with a whale-tail spoiler, marking where these cars usually need work: the engine's belts, chains and seals, suspension bushings and mounts, and rust in the sills. WHEELBASE 01 BELTS, CHAINS, SEALS 02 BUSHINGS & MOUNTS 03 RUST IN THE SILLS FIG. 1 · WHERE THEY USUALLY GO
964 · Known issue Advanced Distributor and Ignition Problems DIY $200–400 Shop $400–800
cars covered
17
known issues
137
guides
153
torque specs
464

01 The cars

Pick your chassis.

Every car gets the same treatment: known problems with repair costs, guides, torque specs, parts sources, and a buyer's guide.

02 Inside a car page

The whole job, not just the symptom.

Each known issue comes with what it costs at home and at a shop, the part numbers, and where the information came from.

  • DIY and shop price ranges
  • OEM part numbers
  • Sources you can check
Open the E30 page

BMW E30 · 1982–1994 Advanced

Timing Belt Failure (M20 Six)

The M20's weak point is its rubber timing belt. It's an interference engine, so a snapped belt means bent valves and, usually, a cylinder head job. Replace it every 50,000 miles or four years, whichever comes first, and do the water pump and tensioner at the same time. The four-cylinder cars are different: the M10 and M42 use timing chains, so there's no belt interval to track. On a high-mile M42, listen for chain rattle at cold start, which points to worn guides.

Do it yourself $150–300
At a shop $500–900

Parts

Timing Belt (M20)11 31 1 711 081$30–50
Tensioner11 31 1 308 652$40–70
Water Pump11 51 9 070 755$50–80

Sources: R3VLimited · Bimmerforums

03 Know before you buy

The big jobs, priced.

The failures worth knowing about before you hand over money, on one scale. DIY Shop

  1. 996 IMS Bearing Failure Porsche 911 · 1998–2005 DIY $500–1,000 Shop $2,000–3,500
  2. E46 Rear Subframe Cracking BMW 3 Series · 1999–2006 DIY $200–400 Shop $1,500–5,000
  3. 928 Timing Belt Failure Porsche Transaxle V8 · 1977–1995 DIY $300–600 Shop $1,500–3,000
  4. E90 Rod Bearing Wear (S65 M3) BMW 3 Series · E90–E93 · 2005–2013 DIY $500–1,000 Shop $2,500–4,500
  5. 964 Cylinder Head Stud Failures Porsche 911 · 1989–1994 DIY $800–1,500 Shop $2,500–5,000
  6. E39 Timing Chain Guide Wear (M62 V8) BMW 5 Series · 1995–2003 DIY $500–1,000 Shop $1,500–3,000

All 137 known issues are on the car pages

04 My Garage

Your car, and every job you've done to it.

Add your car and you get its service schedule with the intervals already filled in, a restoration tracker, and a log of every job. Free, and it syncs between your phone and your laptop.

Add your car Build cost calculator

05 Who writes this

ZRG comes from zurückgeben: to give back, to restore. A good restoration gives a car back what time and neglect took out of it.

I'm Zach, a small independent mechanic in the Pacific Northwest, and these are the cars I work on. If something here is wrong, tell me and I'll fix it.

More about ZRG Send a correction

06 Also in the shop

Ask the forum A board for each car. Post the weird noise, the part you can't identify, or the build you're halfway through. Build cost calculator Price out a restoration before you commit. No account needed. Buyer's guides Which version to buy, a printable inspection checklist, red flags, and what a fair price looks like. One for every car.