New Owner FAQ
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Here are some ideas for new owners or owners of cars of uknown
Courtesy of Chuck Denson, Lars - Bend OR, Misha, Tulsa Dave,
DScott, Peter Florance, Mr Coffey
- Read the FAQ at the top of the Bulletin Board. Make sure
your posts meet our guidelines. We're a little fussy, but
that's intended to keep the board friendly and on-topic.
- Check the ground
strap. It comes from the (-) and goes to the body.
surfaces should be clean and tight. Aftermarket battery
cables are poor quality for the most part. If you need
new cables or body to battery grounf strap, order the OEM
BMW cables. They work really well. Disconnect the battery
before doing anything electrical. Also, clean any other
grounds you can find--particularly the cluster of wires
near the front of the fuse box. Also, replace any wires
that look old and/or crappy. Particularly the large-guage
negative and positive cables to the battery and starter.
Check all the fuses and replace bad ones (or super old
ones) with ones of proper amperage. Clean the fuses
holders carefully with a toothbrush or something (don't
use the toothbrush after). There are also ground under
the dash, in the trunk and under the back seat that
should be cleaned up.
- Replace plugs, points (if applicable), cap, rotor and
plug wires if funds permit. The correct spark plug for
stock 2.8 and 3.0 motors is the Bosch Silber (silver) WR9DS. The correct spark plug for 3.3
and 3.5 Motronic (or formerly Motronic) motors is the
Bosch Silber (silver) WR9LS. Both are not cheap but work much
better than platinum plugs and will last much longer than
Bosch Supers or other non silver plugs.
- If the car has sat for a while, the fuel injectors may be
clogged. You can have them cleaned; but I've found if the
car is running, they tend to clean themselves after a few
tanks. So use a good fuel injector cleaner in the fuel
tank (BG44K available at shops and some Toyota dealers is
quite good). Run at least 6 tanks of fuel before making
any decision about the health of the injectors. I've
found the more you drive it , the better it runs - Peter
- Sometimes E12's run hot. Be sure it's running hot. If the
temperature gauge moves around when the heater fan or
headlights are switched on or off, there's a grounding
problem and you can't trust the reading (Peter) Check the
battery cables and engine grounds and get an independent
measurement of the cooling system temperature. Read Cooling System FAQ. Bleed
the radiator. If air is trapped in the system, the head
will not cool itself well and you may not get proper
cabin heat. Use a ratio of coolant/distilled water
dependent on your climate. DScott - "Maybe "flush
the radiator" and the block would be a good idea.
Run clean water through it until it is clear. Replace
your rad. reservoir bottle cap if it leaks or looks bad.
Also, check hoses--particularly under the intake runners--these
seem to rot out after a couple of decades. Refill the rad
with decent coolant (50/50 mix) and (very important)
bleed the system. Take precautions with the old coolant--it's
poison and animals like the taste."
- WD-40 the hood
cable at the handle and the locking mechanism (up
- Change the oil and replace with the proper weight stuff.
Also, change the filter but make sure you replace the
rubber ring and seat the canister properly (assuming you
don't have a modern spin-on type). This is a little
finnicky but worth it. The proper summer weight for most
models in most countries is 20W50. Thinner oil can leak
or burn easier and may cause low oil pressure at idle.
- E12's have great brakes. Very powerful. If the car you
have doesn't have great brakes, they are not working
correctly. Change fluid and rubber hoses first (Peter).
If the front pads are wearing unevenly (thicker on one
pad than the other or thicker on one end of a pad) you
probably have a stuck piston. If so, Rebuild
the calipers and bleed the brakes. Otherwise start with
hoses and new fluid. Every car should have brake fluid
changed every 2 years. Brake fluid absorbs water which
rusts internal metal parts, tearing seals. After you've
flushed your e12, take a look at the other cars in your
- Write with any other questions. Include your location,
model, and year. The only stupid questions are the ones
you know the answer to.
- Keep an eye out for junkyards. Rusty parts cars can be
had for cheap. If you have the funds and space, they can
be a great source of parts and practice surgery!
- Get a Haynes and/or Chilton's manual. Mr Coffey notes:
"I have a Chiltons that came with my E12 and it is
not of much use other than to put it under a jackstand to
add about 1 1/2" height! :) "
- Read the technical FAQ. A lot
of people have gone through the same problems. Don't re-invent
the wheel! There's more detail in the FAQ's then we have
time to include in web-board posts.
- Use only OEM bulbs from BMW. Copper colored after market
bulbs do not have the right resistance and are a source
of problems with particular regard to the turn signal
- Lube all hinges, throttle linkages, door strike plates,
windsheild wiper linkages, etc. White lithium grease
- Perform operational check of all lights, flashers and
- Replace all fluids if funds permit (Brake, Oil, Radiator,
Tranny, differential, power steering) . Power steering
fluid is Dexron II or equal.
- Look for cracked or split hoses by using a foamy water
solution to identify vacuum leaks.
- Check rear differential
mount for metal fatigue and possible failure. (A
- Clean all fuse contact points and look for faulty/missing
fuses. A new set of fuses is cheap and often fixes
- Check Air Flow Meter (AFM) door movement for binding.
This can cause stumbling, lurching and backfire.
- Pre-Purchase: Suspect Rust spots; Rear shock towers,
underneath front/rear window molding, trunk spare wheel
well, trunk-side of rear seat sill, lower portion of
"B" pillar, driver and passenger floor pans.
- Also look for rust just under the vent at the back of the
hood. Also lift the door seals and have a look. Very well
hidden and I've seen it on more than one.
- A good place to start is with the ignition system.
Inspect the cap, rotor, points and plug wires. If the
wires look suspect or if the connections are loose
replace them. Also, take out the plugs and make note of
how they look--clues to how your motor is running can be
found here. Either clean and gap the old plugs or put in
new ones. (Don't cross-thread them when you put them back--also,
use no-sieze when you replace them.)
- Check out the harness that attaches to the underside of
the fuse box (forget the name). It branches off to the
oil sender, distributor, aux air valve,
etc. (on 1977, 530i anyway). These seem to get knocked
around after a number of years.
- Adjust the valves. While doing so check the oiler tube
hollow 'banjo' bolts for proper torque (~ 8ft lbs I think).
If they get loose, the first few cam lobes will be
starved for oil, ruining the cam and rocker arms. There
is an updated bolt from your dealer that has locking
compound built on to it. There's a circle inscribed on
the hex head to let you know it's the new bolt.
- Check the timing. Many of these cars are timed to TDC
instead of the proper 22 degrees before top-dead-center (BTDC).
It will really wake the car up. The timing marks are
viewed through a small window on the driver's side (left
hand side) of the transmission bell housing. There is a
pointer cast into the window opening that should point to
the 22º BTDC timing mark at the specified RPM (varies
with models). Automatic transmission cars use a long peg
(22º BTDC) and short peg (TDC) pressed into the flywheel
for timing marks. The manual transmission cars use a
steel ball (22º BTC) and the characters "0T" (TDC)
stamped on the edge of the flywheel. One of my cars has
no timing marks on the flywheel. Why, I don't know. I use
an adjustable advance timing light set to 22º BTDC and
strobe the TDC mark on the front harmonic balancer.
There's a pointer on the lower timing case cover that
should line up with the TDC marks (marked 0|T ). Timing
adjustments should be done with advance and/or retard
hoses disconnected from distributor and plugged. Most e12's
with M30 engines should idle (with all hoses connected)
around 10º BTDC. Any major difference from that may
point to an advance problem.
- If your engine runs poorly or not at all after rebuild or
head remove and reinstallation, it's possible the cam or
distributor timing is incorrect. When the #1 cylinder on
the engine is at TDC (compression stroke) the pointer on
the front timing cover should be pointed to the 0|T mark
on harmonic balance. The distributor rotor should be
pointing at # 1 spark plug and the cam should be at the
TDC position. Click here for a picture of the cam
sprocket properly aligned. Both #1 valves should be
closed (cam lobes pointing down).
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