M535i Buyer and Maintenance Information

This is a collection of maintenance, repairs/problems, that one must do to the E28 Big Six cars. A lot of the information is pertinent to the E12's as well. Also, there is a good listing of great FAQ for almost anything you can do to the cars!



  • Oil Service: every 3-6k miles
    -Oil & Oil Filter
    -Check Power steering fluid, brake fluid, clutch fluid
    -Check steering box & linkages
    -Check brake calipers and rotors and pad wear
    -Inspect brake system for damaged hoses and lines, leaks or damage
    -Check and adjust handbrake
    -Check and adjust tire pressures
    -Check headlight and driving light aiming and adjust if necessary
    -Check operation of all electrical lights and equipment
    -Check active check control panel
    -Check function of seat belts
    -Check windshield washer fluid level, operation, and wiper blades
    -Road Test

  • Inspection I: every 10-15k miles
    -Check and adjust valve clearances
    -Oil & Oil Filter
    -Check battery acid level
    -Check coolant level and anti-freeze protection, inspect for leaks
    -Lubricate accelerator linkages and throttle linkage
    -Change auto tranny fluid and strainer
    -Check manual tranny oil and add if necessary
    -Check final drive oil and add if necessary
    -Check fuel tank, lines, and all connections for leaks
    -Inspect exhaust system
    -Check steering box and linkages
    -Check brake calipers, rotors, and pad wear
    -Inspect brake system for damaged hoses and lines, leaks or damage
    -Check and adjust handbrake
    -Inspect front suspension and steering for play
    -Inspect wheels and tires, check pressures and condition
    -Lubricate door hinges and hood latch
    -Check headlight and driving light aim and adjust if necessary
    -Check operation of all electrical equipment
    -Check active check control panel
    -Check function of A/C and refrigerant charge. Tighten A/C compressor mounting bolts
    -Check function of seat belts
    -Check windshield washer fluid level, add if necessary, operation of system, condition of blades
    -Tighten nuts and bolts for door locks and striker plates
    -Road Test

  • Inspection II: every 20-30k miles
    -Check and adjust valve clearances
    -Replace spark plugs
    -Oil and oil filter
    -Check engine timing belt tension (on 528e)
    -Check brake fluid, power steering fluid, clutch fluid
    -Check and adjust V-belt tension and check condition
    -Check battery acid level
    -Check coolant level and anti-freeze protection, inspect for leaks
    -Lubricate accelerator linkages and throttle linkages
    -Change air filter
    -Check/change auto tranny fluid
    -Change manual tranny fluid
    -Check clutch plate for wear
    -Check drive axle boots for wear
    -Check front wheel bearing for play
    -Change final drive fluid
    -Check fuel tank, lines, and connections for leaks
    -Change fuel filter
    -Inspect exhaust system
    -Check steering box and all linkages
    -Check power steering system for leaks
    -Check brake caliper, rotors, and pad wear
    -Inspect brake system for damaged hoses and lines, leaks or damage
    -Inspect parking brake cable, adjust if necessary
    -Inspect front suspension and steering for play
    -Inspect wheels and tires, check pressure and condition
    -Lubricate door hinges and hoot latch
    -Check headlight and driving light aim and adjust if necessary
    -Check operation of all electrical systems
    -Check active check control panel
    -Check function of A/C and refrigerant charge. Tighten A/C compressor mounting bolts
    -Check function of seat belts
    -Check windshield washer fluid, operation, and condition of blades
    -Tighten nuts and bolts for door locks and striker plates
    -Road Test

  • Oxygen Sensor every 50k miles
  • Brake Fluid every 12 months
  • Coolant Flush every 24 months

  • Water Pump: 50k
  • Fan Clutch: 100k
  • Manual Tranny Gear Linkages: 100k
  • Driveshafts: 100-200k
  • Guibo: 100k
  • Front end work: 60-100k
  • Rear diff mount: 100k-150k
  • Use Redline!!!


    1) Head, cam & engine
    2) Cooling system
    3) Oil (& oil leaks!)
    4) Other engine compartment stuff
    5) Tranny and clutch
    6) Driveline
    7) Suspension, steering and brakes
    8) Interior, Electrical
    9) General (catch-all)

    1) Head Gasket and other Engine Notes:
    - Bottom ends last upwards of 300k
    - Top end work $1500+ for parts (do all belts and hoses, too!) and shop time.
    - Compression or leak-down test very informative, look for 160+ on all cylinders, +/- 5 OK, +/- 10 marginal. If you want details on my many recorded numbers, or a rap on the leakdown test, drop me a note.
    - Rough Idle - Multitude of problems. See the FAQ.
    - If you pull the valve cover (which I would recommend) check that the two 12mm head 'banjo bolts' that secure the oil bar to the head are snug. If these are loose this is _bad_ (refer to definition above). There is a new variety with a thread-locking feature, distinguished by a circle on the top. (somebody might drop me the correct part number - I thought I had it, but my local dealer sneezed on hearing it).
    - Check the cam rubbing surfaces: the peaks of the cam lobes should have no discernable wear (using the patented fingernail technique) and the rubbing blocks on the underside of the rocker arms should all appear the same in profile. If the banjo bolts were loose, TAKE YOUR TIME doing this part! If replacing the cam, add $300 to head job.
    - Easy things to look for in this department: coolant. If someone is concealing a known head gasket problem, the coolant may be clear and/or rusty, meaning they consume a lot, and have been just adding water, or the coolant may be suspiciously clean, meaning added to all the time.
    Spark plug condition. In addition to the normal interpretation found in every Haynes manual (the color picture page), look for differences in plug color. Cylinders leaking coolant will have very clean plugs. Pressure washed, if you will.
    - Coolant burners (cracked head or bad head gasket) will put out reams of white smoke (actually steam) when they are first warming up. Smells kinda sweet, not unlike coolant.
    - Coolant system pressure and leak-down useful, but not definitive for head leak problems. Cracks, or high porousity areas may not show up with a static pressure test.
    - If you are looking at an 'e' motor and do not have conclusive proof that the timing belt has been replaced in the last 5 years or 50,000 miles, just do it. Better than bent valves, etc.!

    2) Cooling System
    - It's my experience that radiators are a 8 - 10 year consumeable. The E28's have aluminum cores with plastic tanks clipped to them with one-time-use crimps. And, the plastic ages badly, leading to broken hose connections, etc. Not worth repairing IMHO, but some Digesters have had good luck with Reseda Radiator.
    - From underneath with a light, find the 'weep-hole' just aft of the fan clutch mount. Should have no 'tear-tracks' left from a bad bearing seal.
    - Belts and hoses should be uncracked and not bulgy, respectively.
    - Temp guage should run at 10:30 to 12 o'clock under any and all conditions. After a test drive, leave it idling for 15 minutes or so and see what it goes up to and settles at. Anything over 12 o'clock means maintenance coming up. Radiator likely, typical consumable. $240 part.
    - If suspicious of guage/sensor inaccuracy, wrap your hand around the upper radiator hose: if you can squeeze it for an indefinite amount of time, <50 C, not warmed up yet. Hold several seconds, 70 - 90 C, OK. Can't hold 1 second, >90 C, which means trouble. Or, use a candy thermometer. But hey, you probably had your hands in your pockets and NOT a thermometer!
    - Check fan clutch. Should not freewheel when spun, but have a certain resistance. Should give more resistance at temp, but this is hard to 'feel', in my experience. $30ish.
    - Heater control solenoid fails, resulting in erratic heat, or heat all the time. Easy fixes, write for details. $25 for kit which replaces innards.

    3) Oil and Oil Leaks
    - Visually, 'fresh' oil will appear a clear brown, as you know. Black just means old, any cloudy or white means water, which is very BAD, 'bad' being defined as like crossing two anti-proton streams resulting in the destruction of the universe as we know it.
    - Check under oil filler cap: there should be no cloudiness, and gives you an idea of internal cleanliness (which is good).
    - The owner's manual says it is 'OK' if the oil pressure light comes on 'at times', like idling when hot, but should go out when revved. Drives me crazy if it comes on at all!
    - The oil pressure sender is a frequent leaker. The leak will track down the side of the engine and drip off the lowest point of the bell housing, so don't confuse it with other potential problems.
    - The pan gaskets occasionally 'creep' out of their space and self-destruct. If you go in to replace this on a high miles motor you intend to keep, replace the oil pump (and probably the sprocket) at the same time. $150ish, and well worth it.
    - Blue smoke = worn valve guides or bad piston rings (VERY bad)

    4) Other Engine Compartment Stuff
    - All fuel lines are suspect by 100K - especially the short hank to the cold start injector at the lowest extreme of the intake manifold, for some esoteric reason. Don't use cheap stuff! Buy the BMW 8 x 13 mm stuff from one of many sources.
    - Cold Start Valve is suspect at more than 100k.
    - Vacuum leaks are a major hassle. Prime symptom is rough idle, flat spots at mid revs, may also be fuel pressure regulator. Do easy candidates first: put an o-ring in one of the grooves in the dipstick top. Put clamps on the hoses to the valve cover and idle motor (if E28). Replace the hard-as-rock hoses in general. Replace the fuel injector o-rings.
    - Look at the brake fluid. Black is _bad_, but at least means it wasn't being topped up each week (see 'slave' discussion below). Color of the brake fluid is a very good indicator of the general tenor of the maintenance regime for the car. If it is black as pitch, indicating it is _not_ getting the yearly replacement the anal-among-us so lovingly do, check more closely for all the other maintenance opportunities.
    - Lots of things can make this baby idle rough; already mentioned vacuum leaks. Mucho covered in FAQ's. Best I have seen is by Sam Lin for a copy.
    - Plug wires are a 100k consumeable in my book. Cleap insurance, can help several marginal symptoms, lotsa sources, $80ish.

    5) Tranny and Clutch
    - No experience with the 4-speed auto, so no comments.
    - Autos have a habit of going kaputt by 125k miles. Don’t rev them in park or neutral.
    - The Getrag 5-speed should enter all gears smoothly - they are not especially prone to synchro failure in normal operation (i.e. not auto-x'd) but most are 'notchy', kinda hard to push into gear, especially when rev's not synched, but easily improved by putting in Redline MTL tranny oil.
    - Every 100K+ Getrag I've seen leaks. From the rear is OK but messy - shift shaft seal fails, soaking back of tranny. Output shaft seal weeps, no major heartache. Seam between front and rear half of tranny case weeps, wets bottom of tranny, but no sweat. Saving the best for last: If there is oil (not brake fluid, see below) coming out of the drain hole in the bell housing, either the tranny front seal is leaking, (likely) or the engine rear main (possibly). This is _bad_ (see definition above) because the clutch is not designed to be oil-bathed, and will tend to chatter and fail. Seals are $5-$10 each, clutch trio (pressure plate, clutch disk, throw-out bearing) are $300ish. All quite doable, but considerable labor, dropping exhaust, removing driveline.
    - Clutch pedal should depress smoothly, although with a lot more force in the 535i than the 528e or a 3-series. Should not hang up on either the upswing or downswing - that could be broken 'ears' on the throwout bearing.
    - Stick your fingers under the forward edge of the dash sound cover just above the brake pedal and feel for wet, and smell your fingers - odor of brake fluid means the master is leaking.
    - Also check for clutch master cylinder flex to one side when the pedal is depressed - the pedal bracket mounting the master cylinder fatigues and cracks, allowing the master to move around. Time-consuming to replace, but not hard. Usually around 150k.
    - If brake fluid is leaking out of the drain hole of the bell housing, the clutch slave cylinder is leaking - very common, but cheap and easy to fix. Smell it to distinguish from oil, but bear in mind that you could be getting both. Another tip-off for this one is really clean brake fluid, from someone topping it up as it coats their garage floor. Another symptom for the slave being bad is that the clutch disengages very close to the floor, or the pedal will not return.
    - While you're down there, check that the rear tranny mounts have not gone to mush, they do that. Check the engine mounts too; check for cracks in the top, especially on the right.
    - Many of these beasties have developed a lot of play in the shift mechanism: worn shifter bushings, mushy rubber mounts on the shift pivot mounting plate. Stock shifter bushing parts will cost you $35-$60 at a dealer, Korman shifter, UUC, Auto Solutions, or ACS shifter. No affiliation.

    6) Driveline
    - Check guibo, the rubber flexdisk connecting the output of the tranny to the driveline. At 100K it will be cracked, and may be the cause of a shudder at certain speeds (frequently 25 to 35 mph), especially while under load.
    - Ditto the center bearing and support, but much harder to check, as you have to dispose of the exhaust system (well, remove enough to get the heat shield off, but you know what I mean!).
    - Do the traditional twist-drive-components-and-note-any-play of the two U-joints. The rear one is the more likely to fail, and is easily observed. Bear in mind that if they are bad, you will need to get the driveline rebuilt, $450ish if you rebuild the whole thing (recommended).
    - Driveshafts last between 100k (abused) and 200k or more

    -One thing I can contribute is a problem inherent in the E-12 chassis, and aggravated by the power and torque of the M535i engine: cracks in the frame where the differential bolts onto it. I have a first-rate technician, who knew about the problem, looked for it on his own when my car was in for servicing at one point, and solved the problem, as he has done for a number of E-12s: take steel reinforcing bars, wrap them around the differential housing, bring their ends up through the trunk and them bolt them together with a reinforcing plate. I have had no problems in the year that this has been done.
    7) Suspension, Steering and Brakes
    - There are books written on the subject of the front control arms, but the exec summary is: they all die. Symptoms of impending doom are shuddering when braking, especially from say 65 down to 45. May get very jumpy at the steering wheel. There are upper and lower control arm bushings and ball joints, and lots of alternatives (bushing upgrades, etc.). FAQ's abound. $160-$800 in parts.
    - And, of course, the front rotors warp. $120ish. Always replace the 5mm hex that secures the rotors. Cheap insurance.
    - The 535i boost system feels weird (the 528e is a very vanilla vacuum boost.) The point is; in a perfectly healthy hydralic- boosted system, you can 'surprise' the system if the engine is running but the car is standing still by stomping the brake pedal hard - you can make it most of the way to the floor. Not to worry; you are 'way past the point that triggers ABS, but tech checks for track days may be tricky - the typical M3 driver doing the check will panic. Explain ahead of time!
    - Brake Pressure accumulator can go (you get a brake light popping up when standing on brakes) at more than 80k miles.
    - With the engine running for brake boost, stand on the brake pedal for 30 seconds or so. If it drifts toward the floor, time for a master cylinder. Replace, don't rebuild. $80 to $180, +/- year and/or ABS.
    - Steering should be 'tight' when gently rocked at the center of travel when the engine is off. 'Clunks' may mean Pitman arm bushings (_bad_), loose collar nut under dash (easy) or bad center track rod (cheap, <$60, but obnoxious).
    - Rare power steering pump bracket failure - $1000 repair or reinforcing it at lower cost.
    - The two senders on the brake pressure regulator regularly leak.Replace them both, $32ish.
    - There is a 'nitrogen ball', frequently referred to as the 'brake bomb', due to it's cartoon-bomblike appearance, that dies. Symptom is a slow-to-respond brake pedal, frequently accompanied by a flash of the 'brake' idiot light, and/or no brake boost immediately after shutting down the engine. (It should give several-to-many 'assists' after shutdown). Again, several fine FAQ's on replacement (somewhere). $60ish.
    - When checking the p/s and brake boost fluid level, bear in mind that if the engine has been running and the nitrogen ball is in working order, there is a inch or so of fluid in the ball. Fully discharge the ball by stomping the brake pedal 10-20 times and watch the fluid level creep up. Adjust to the line in the side of the can at that point. This applies to the 'i' only; as the 'e' uses vacuum boost.
    - Steering box bolts should be checked. They come loose.
    - Fluid should be pretty; not black. There is a filter in the bottom of the reserviour that should be changed on the 'i'.

    8) Interior, Electrical
    - Door locks like to go on the fritz. The Dead-lock feature can fail (mechanical really not electrical- easy fix). Check Rich’s page.
    - Alternator brushes ($5.50 at BavAuto) are typical 140K items. Two screws pop the assy off the back of the alternator to check.
    - Weird guage problems (tach or mpg guage erratic, etc.) indicate a possible SI battery replacement needed. Very typical, and lots written on the subject.
    - Dead SI batteries may also cause the Oil Service lights to be on at odd times. <$10 for batts, couple hundred for rebuilt board.
    - If batt's are OK, lights are very easily reset, refer to FAQ's and/or reset tools, or, for the very brave, just ground pin 7 of the diagnostic connector, turn on the ignition (but don't start) for 15 seconds, turn it off, and you're done. Many will tell you this procedure is highly risky, but so is cutting vegetables with a dull knife - sheesh! no rocket science here. (15 pin version)
    - Jump pins 11 to 14 for remote start.
    - Headrest up/down dies. Easy fix, good FAQ's elsewhere. $0.
    - HVAC heater control valve can die (get binary operation of HVAC system or hot when going more than 50 mph). Flaps are also a niggling problem.
    - Just an observation: window lift and sunroof switches were illuminated 'standard' in late '86 US cars on. Easy swap, wires already in place, as an easy upgrade. I got a set from Jason at Zionsville, very cool outfit (no affiliation, yada x 3) Also, they get mechanically sticky and electrically erratic if exposed to Armorall. Switches can be opened and cleaned.
    - Fuse box has chronic, but easy problems. Fuse clips corrode, wirebrush 'em. Fuses corrode, replace 'em all. Connections inside the box can get erratic or hot. A real bear to troubleshoot.
    - Sunroof drains can get blocked and then the water can make the C-pillar rust from the inside. Watch out for rust at the base of the C pillar (right near the edge of the rear door). It's a chronic place for E12's.
    - Several chronic problems show up as 'cutting out' at any speed, frequently the 'main' relay, sometimes the fuel pump relay, sometimes the position or timing sensors. Connections to the _underside_ of Fuse 6 can corrode and heat up.
    - Several handy voltages to know, measured at the battery:
    10.0v - voltage while cranking starter`
    12.3v - 50% charged battery, 'at rest'
    12.7v - fully charged battery, 'at rest'
    13.6v - minimum acceptable alternator output at idle
    14.3v - maximum acceptable alternator output at revs
    Ref: Mark Calabrese article "In the Dark?" March, 1996 Roundel

    9) General
    - Don't believe a _dang_ thing a salesperson says, if there is not documentation behind it. "Changed the oil every 3K miles" if literally true means they _never_ changed the filter. Semantics? Maybe. The car tells the real story, a salesperson has a car to sell.
    - Lots of exhaust replacement opinions, choose one you like. The E28 cats crack, but can be successfully welded for years.
    - Exhausts can go as early as 100k.
    - Water in the trunk is usually a bad (hardened and/or cracked) rubber gasket around the taillight assy's. Replace them both. Watch the sunroof drains as well.
    - Fuel tanks can leak near the fuel filler neck. Rust. Rare, but watch out.
    - Fuel Transfer Pump can go between 70k and 150k. Usually has hesitation when less than ¼ filled in tank or makes a loud buzzing noise (actually the main pump being overworked)
    - Buy a Bentley manual, and an ETM (Electronic Troubleshooting Manual) if you are electrically astute.
    - Check to see if it has the TRX tires. If so, you face one of the classic $$$ delimmas - discount asking price $400 if tires OK, $1000 if tires need replacement. Many details elsewhere.


    -Big Coupe Gruppe FAQ -
    -Richard Cartledge’s Tips - (Unfortunaltey NLA)
    -Buyer’s Guide (What to Check for) -
    -Chris Guy’s Buying Advice and FAQ -
    -Unix Nerd’s Domain Fuel Inj. Prob. Solv. -
    -Steve Bernstein Brake FAQ -

    - For an excellent treatment of all the E- and M- numbers, check: John Burns' page.

    My thanks to Mssrs Anderson, Boylan, D'G, Eilenberger, Levinson, Lin, Stock, Tangen, and Welty, without whom this would all be impossible.

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