Rod's Automobile Pages...

Maintenance Tips Pg. 1

Maintenance Tips Pg. 1
Maintenance Tips Pg. 2
Maintenance Tips Pg. 3
Maintenance Tips Pg. 4
More Maintenance Tips (rear bushing replacement, the EZcarlift in action, etc.)
Modifications and Resources Pg. 1
Modifications and Resources Pg. 2
Modifications and Resources Pg. 3
Modifications and Resources Pg. 4
Modifications and Resources Pg. 5
Paint Protection
Electrical Problems
Lighting Voltage Drop Tests - Headlight lens polishing
BMW E28 Steering Wheels
Eric's Autos
Shelley's Autos
Other E28 BMW's
Rod's Honda Fit page
About Rod and links to his other web pages.
Maintenance tips, comments and links about
performing various types of maintenance.
This page last revised April 16, 2013
Mike's tip of the week (created by Mike W. at Not really a weekly tip, but it has all the good ones plus others added by Forum members, on a random basis. Last updated October 6, 2011)
Adjusting the AFM (the original webpage is gone, this is a link to my .PDF copy)
Idle FAQ (new location 12/3/09)
Idle Issues (325 eta but still applies to 528e. Added 4/16/13)
BMW Parts Catalog (ETK) (this is the web site)
Getting Trans Fluid into your Manual Trans (link updated 10/10/12) with the StaLube pump and a Listerine bottle is a simple task. The Listerine bottle is short enough to allow pump operation with a moderate vehicle height and the tube is long enough to go into the transmission filler opening, by feeding the tube up over the exhaust pipe next to the filler plug. Have a friend available to add fluid to the bottle, as it will take about 1-1/2 bottles to fill the transmission up.


Removing a frozen or damaged disc rotor mounting screw
These are a problem on a lot of brake jobs, as they are usually incorrectly installed (too much torque, no anti-s
eize compound, worn hex head wrench, etc.) and may have to be drilled and extracted, inorder to get the disc rotor off.

First, if the metric head (5mm) of the rotor screw is not badily damaged or rounded out, you may be able to get it out with good condition 5mm 3/8-inch drive hex head wrench and an impact ratchet tool.


If the impact ratchet doesn't do the trick, get a Number 3 Extractor (Sears has them) and a very high quality 5/32-inch drill bit. Very carefully drill out the center of the hex head mounting screw to about 1/2-inch. Be careful not to drill at an angle and go through the side of the screw and into the threads in the rotor hub, creating another problem for yourself.

Remember, the Extractor works backwards... you start it into the screw in a counter clockwise direction, since once it catches you will be backing it out. You can see that while this screw had anti-seize on it, the problem was that it had a damaged head, with the hex slot totally rounded out! Never reuse these screws!
Replace the rotor screw with a new one and make sure you use a good quality anti-seize compound on it. Most important, DO NOT tighten this screw down too much! Its job is to simply hold the disc rotor on the hub, when the wheel mounting bolts have been removed. Bently doesn't give a torque amount for this screw, but I'd never put more than 5 ft. lbs. on it, if even that much. Next time, you, or whoever works on the brakes will be able to remove this screw easily, because you put it back together correctly.
Lastly, here is a good article about extracting broken bolts, (updated 10/10/12) should you find yourself faced with one someday.

Temporary Hydraulic Plugs/Caps
Next time you renew your brake line hoses, keep several of the old ones to modify so that they can be used in the caliper and at the metal brake line end fitting to keep the hydraulic fluid from leaking out. I simply cut mine about an inch from the brass fitting, soaked them in paint thinner to clean them out and filled them with 100% Silicone caulking, capping the end with the protective end caps that come on the new hoses. They work great.

Click to convert torque specs like Nm, KG-CM, etc., to inch-pound, foot pound, etc.

Click to convert fuel mileage mpg to litres per 100 km and other measurments.

Update Apr. 19, 2007 -
Summary of Emission Test Results
In my location in Virginia, emissions testing started in 1999, with each year tightening the specs of the emission levels.
Emissions Test 1 - 3/18/99 117,310 miles, stock "007" ECU/DME
                  15 mph          25 mph
              Limit Reading  Limit  Reading
    HC ppm     173      3     168      11
       CO%    0.98   0.01    1.08    0.01
    NO ppm    1323    126    1208     194
       RPM           1512            2352
Emissions Test 2 - 3/8/2001 120,005 miles, stock "007" ECU/DME
                  15 mph          25 mph
              Limit Reading  Limit  Reading
    HC ppm     167     12     162      23
       CO%    0.94   0.02    1.04    0.08
    NO ppm    1273    223    1163     220
       RPM           2456            2409
    No test required in 2003. DMV error?
Emissions Test 3 - 3/31/05 123,952 miles, D'Sylva ETA chip in 1987 325e "027" ECU/DME
                  15 mph          25 mph
              Limit Reading  Limit  Reading
    HC ppm     125     25     121      58
       CO%    0.70   0.05    0.75    0.21
    NO ppm     972    258     885     346
       RPM           2361            2281
Emissions Test 4 - 4/17/007 129,188 miles, D'Sylva ETA chip in 1987 325e "027" ECU/DME (note changes in limits 2005-2007 which actually increased. Also, 93 octane gas is now used which has no Oxy additives.)
                  15 mph          25 mph
              Limit Reading  Limit  Reading
    HC ppm     102      4     185      20
       CO%    0.41   0.00    0.59    0.10
    NO ppm    1333    231    1296     501
       RPM           1689            2789
April 2005 -
124k miles maintenance items, including "Preventive Maintenance" items such as radiator, expansion tank, water pump and thermostat.
- New Behr radiator, as current radiator is original 22+ year old unit. General concensus is that it should be changed simply due to age, as these radiators have a history of breaking at the hose connection, with their "plastic" end tank material, not brass.
- New radiator expansion tank, to replace original plastic tank, now 22+ years old, discolored and brittle filler cap neck.
- New radiator hoses and all engine bay fuel and vacuum hoses. (4 years old)
- New fuel filter and new hoses for filter and fuel pump. (4 years old)
- New timing belt, as it is due according to age (4 years old), but mileage is only 29k.
- New water pump to replace existing unit, also 4 years old with 29k miles on it.
- New water pump, alternator and AC compressor drive belts, now 4 years old.
- New cam front seals, as that area is now showing some oil seepage, running down the face of the head and block.
- New Oxygen sensor to replace existing unit due for replacement at 120k miles.
- New thermostat and O-Ring seal.
- Remove and paint valve cover gloss black, with raised/molded trim areas left aluminum color. Simple dress-up change for engine.
- New valve cover gasket and new valve cover blind plugs, after valve lash check and adjustment. Valve lash adjusted annually, in spite of low annual mileage use.
UPDATE January 8, 2013
Non BMW Hose clamps -
When changing the hoses, make sure you replace any non BMW type hose clamps with the proper clamp, and get rid of any cheap yankee (a term used by the Mercedes guys) hose clamps. A fellow E28 owner I recently assisted, complained of hard starting and a smell of gasoline! Turned out to be a yankee clamp that had a stainless steel band and housing, but a cheap rusted away plain metal screw that allowed the band to open and gas to leak from the main fuel pump output hose connection! The fuel pressure at the output of the main fuel pump is 100+ PSI! Get rid of these cheap hose clamps! Get BMW labeled replacement clamps from your BMW dealer or get the Wurth ZEBRA style hose clamp. (1/8/13 - Select the Section 7 Service And Repair catalog PDF file, which includes the hose clamps listings)



And where are those timing reference marks?
This is "Top Dead Center", as indicated by the line on the damper (bottom arrow) and the raised marker (top arrow) in the face of the belt cover housing, just above the top edge of the damper, lined up with each other. I've included it here since quite a few people aren't sure what to look for, as manual photos are not clear enough.
NOTE - The radiator has been removed which is being replaced with a new radiator. This allows these pictures to more clearly show the items being addressed here, while the radiator is out of the vehicle.
The Cam gear, cylinder head and crankshaft timing marks are shown below.
Cam gear and cylinder head timing marks.
A white grease pencil was used to highlight the cam gear embossed arrow and the edge of the cam gear tooth directly in line with it. Yes, the belt is one tooth off... thanks to BMW dealer service! You have to get down on your knees with your chin right on the top of the front grille, in order to site these marks properly. Otherwise, you will not see what the actual alignment is. And make sure you are making this alignment check after you have rotated the engine two complete revolutions to set the belt tension, as specified in the Bentley manual!
Crankshaft and housing reference marks for the timing belt alignment.

New Valve Cover Blind Plugs.
Don't forget to replace the Valve Cover Blind Plugs, for the rocker arm shaft ends. Too often overlooked and a big trouble maker for the timing belt if the front plugs start leaking... and they will if they are old and dried up and will ruin the belt way before its time! Leaky plugs will also create idle mixture problems since they'll be leaking air. A difficult problem to find and few people actually give thought to these plugs, as I've traced quite a few 528e vacuum leak/idle problems to these Blind Plugs on other owners cars! Keep extra's on hand, they are less than a buck a piece!
Ready for new timing belt, tensioner, water pump, drive belts, thermostat and radiator.
Before you start putting everything back together (except for the cam front seals) take some time to clean up the area, including "chasing" any threads that may need to be cleaned up due to corrosion, dirt, etc., and the same for the bolts going back on the engine. A clean engine makes it much easier to see future potential trouble spots and it's well worth the effort. Additional info and pictures are available at Pelican Parts, dealing with a belt change on an E30, but still the M20 engine.
NOTE - AC Compressor belt remove/replace
On my eta engine, the compressor is mounted via a plate that is secured at the top by four cap screws (see picture above), two in holes next to the block, two in adjustment slots toward the fender well, with a single large pivot bolt at the bottom. Because the clearances are so tight, the only way I've been able to replace this belt is by removing the top four cap screws (you can see in the picture above, that the plate has been moved off its mounting points) and the bottom pivot bolt. Then the compressor can be moved close enough to the block, including the ability to angle the front of the compressor toward the crankshaft, to allow belt removal. I've also changed the belt from a 818mm length to a 825mm, which gives needed additional length to allow belt installation. Still not an easy task, but it can be accomplished by yourself, without assistance from a friend, a pry bar, or the starter motor!
Update October 11, 2012
On the older M20 engines the cam belt gear and the idler gear are pressed metal and some have been found to fail due to age, fatigue and rusting. These gears were updated in late 1986 to what is known as the 'SINTER' gear, which is a much more robust gear construction. If you have the older stamped gears, you should replace them, which is what I have done. A forum thread discussing a broken older stamped style Idler gear is here, although the photos are poor quality.

When the timing belt BREAKS!
Update June 13, 2011
Too many M20 timing belts have not been properly maintained, resulting in the belt breaking and bending a few valves, at the very least, or causing the complete distruction of major engine components, such as its cylinder head and its pistons, as shown in these pictures provided by "south26" at, of an M20 engine out of an E34. He was told that it only had a "blown headgasket"! You can go here to see the original discussion on
Unless the person you are buying an E28 or M20 engine from, has a valid receipt or service work order for having the timing belt changed within the last 4 years or 50,000 miles, don't simply rely on their word. Install, or have installed a new timing belt IMMEDIATELY! If you don't, you certainly face the very real possibility of a broken timing belt and the breakage of associated components... if not major distruction, as this M20 engine suffered.




Update July 15, 2010 -
Lastly, if you are attempting to keep your air conditioning system operating properly, here are a couple of articles you may find helpful.
My system is still an R12 system, which I keep charged using Freeze12, about one can every three years to top it off. Measured temperature using an accurate digital temperature probe at my AC vents runs between 38F to 42F depending on outside air temperature. Most recent maximum outside temp was 100.6F with 42F at the vents. Simply saying that your system "blows cold" is meaningless, as many such systems that I have measured were actually producing only 56F to 65F air, which is well below what a properly functioning system produces. It may feel "cold", compared to the ambient temperature you may be measuring it in, like a 95 degree day, but that is not an accurate measurment! Use an accurate temperature probe to find out what your actual "blows cold" air temperature is!
Additional info about measured actual AC output air temps is here.
Work nearly completed and then out on the road for testing.
A used M20 rocker arm cover was purchased and painted, to replace the original rocker arm cover. Watch out if you buy the same thing. I bought one that had been "sand blasted" to prep it for painting, but the inside where the crankcase ventilation takes place was full of junk. Looked like the M20 engine it came off of never had the oil changed. This had to be dip cleaned before painting, of course.
The above picture was taken before the strut brace was installed and the vacuum line running across the top of the rocker arm cover has since been re-routed to run along the top of the cover, so as not to be in the way during cover removal for valve lash adjustment.

Intermittent/random engine power loss during full throttle
I was experiencing some random engine power reductions, where the engine runs strong, then fades moderately at random times, often only for several minutes, with engine power coming back. Not a major engine power loss, but the kind that you know something is wrong, as she isn't pulling as strong as she usually does at full throttle.
Since this was occurring during my ECU chip testing, I attributed it to a troublesome ECU or a bad connection, due to the ECU cable swapping. I would find it once it got worse or lasted longer and I knew which of three ECU's was the culprit. At the same time, I was doing the 124k miles maintenance and decided I'd test the fuel pressure regulator since I was replacing its vacuum and fuel hoses.
Well, the fuel pressure regulator (original 1982 unit), was measuring too low at 29.5psi (2.03 bar). Supposed to be 33.4psi MINIMUM. Further tests showed the fuel pump was okay. The new regulator measures 37.8psi (2.61 bar) and the engine now has considerably more power all the time... with the intermittent power reduction now gone. So, the old original fuel pressure regulator was at fault, letting fuel go back to the fuel tank when it wasn't supposed to. A leaky or worn valve. Not sure how long it would have taken me to find this, if I hadn't done the pressure test while replacing hoses. I'd probably still be trying to find an ECU problem!

Blown/Broken Hard Disk Drive - Don't Throw it Away!
If you have a hard disk failure, or simply upgrade an old disk drive, take the unused drive apart and remove the two magnets inside, as they are very, very strong and can be used for many things. Below is a picture of a drive that had a massive failure, showing where the magnets are located.

This is a typical magnet assembly, some have two small magnets that are side by side. The magnets are cemented to their mounting plates. You may be able to break the bond and get them off, but often this breaks the magnet. I leave them on their mounting plate which makes them easier to handle.
One good use of these magnets, besides using them to magnitize screwdrivers, is to use them for holding things while working on your vehicle. Below you can see how they are used to hold a lightweight cloth lined vinyl fender protector to keep it from moving. There are many uses for these very strong magnets... just keep them away from friends with metal plates in their head!


AC vents a mess?
Unfortunately, a lot of really nice E28's have filthy AC vents staring you in the face. They are easy to clean. I use a slim pair of needle nose plyers and grasp the vent at the center of the side, where the plastic pivot pin fits in the open ended C shaped pivot hole. It's a compression fit, so a moderate amount of pull is necessary. You can see how it is retained in the photo below.
Once removed, I've found that cleaning them in hot soapy dish water works best. Use a Q-Tip to get into the vent blades. Blow it dry and touch-up any spots with another Q-Tip. Replace the vent by installing one side of it first on its pin, then snap it on to the other pin. Don't forget to wash the vent housing and the flapper valve. Once complete, they look great.
If your blower fans are squeeking or slowing down, get some turbine oil, like Sid Harvey's and lubricate the fan and motor bearings.

- Suspension description
- Pitman arms replacement
- Replace speedometer gears
- A hidden rust area
- Hood pad replacement
- Cooling system questions and which temp sensor does what?
- Placement of rear Jack Stands
- Front Strut Water Drain and what can happen due to rust! I've expanded this subject due to the number of failures I've now seen due to the rust problem.
- Bell Housing Sensors Installation, which sense flywheel rotation and position data for the ECU/DME ignition control.