Puzzle scenario: You lend a close friend your BMW E30 automatic to make a much-needed long-distance trip. The friend is on his way home and calls late at night. He says he’s still an hour away from home.The lights on the E30 got dimmer and dimmer and then the check engine light came on a few times and then the engine cut out. Now the car is dead by the side of the freeway somewhere in the boonies. You call around, find a nearby 24-hour towing service and arrange to have the car towed there and your friend taken somewhere safe where he’s welcome to wait but not spend the night. No problem, says the towing guy, and there’s even an auto repair shop right across the street. Now what?

Hints: Screwing this up will …
1. Be very easy because if you let events unfold in their typical way, you’re pretty much doomed.
2. Be done by others, most likely rather then you personally doing the damage
3. Destroy the transmission on your E30, or the E28 you are about to drive to go get your friend, or both.

For extra credit, to make this harder, let’s also say:
A. You’re a charming, pretty girl in whose presence guys such as tow truck drivers and auto mechanics act all macho, wise and helpful
B. This is happening in the American South
C. You’re so smart that there’s s a good chance you’re likely to be the most intelligent person in the ZIP code, especially that ZIP code

The combined effect of A, B and C is that you’re accustomed to pointing out well-founded concerns to guys, and being ignored except for literally hearing the response “don’t you worry your pretty little head about that.”

And no, the pretty girl isn’t me. It’s someone I care about very much.

Wait, what? What does any of this have to do with the automatic transmission on each car?

Well, here’s a one-paragraph explanation. These ZF 4HP-22 units are wonderful automatic transmissions. They were used in almost all BMW models from the mid-1980s to early 1990s, including the E30 325i in our story, and the E28 528e rescue vehicle. Properly serviced or sometimes even when not, they might be 30 years old yet still going strong. The one in my 1989 E30 has probably gone a quarter of a million miles and it’s still behaving perfectly — and I drive my E30 hard. Typically the only way you can kill them is by revving the engine in Park, Reverse or Neutral. It doesn’t take much. Think of the revving that happens during a smog check or right before a juvenile stop light drag race. Yep, that’s enough. In less than a minute, sayonara transmission. Some models have had that vulnerability fixed, but it’s very hard to figure if your car is one of these. Now, let’s think this through some more. What do people traditionally do as part of jump-starting a car, or starting it after it’s been dead? They rev the engine. Not that they need to … the alternator charges well enough at idle speed. But stupid is as stupid does.

So your mission is to somehow get the guys to not destroy the transmission in either car. And you already known you can’t tell the guys not to. They’ll just blow you off and do it anyway. You have to shape the events to prevent the damage.

Slightly edited, here are the instructions I sent to the pretty girl on her phone that night. Did they help? That’s another story. Whether they did or didn’t, I hope they help YOU in a similar predicament. That’s why I’m posting this.

* * *

The highest risk here is that someone will rev the E30 car or E28 car in park or neutral and destroy the transmission in less than a minute. Left to their own initiative, guys will rev a car in park or neutral as part of jump starting, or seeing if the charged battery works, etc. Don’t trust them. Say no and make it impossible — otherwise with the best of intentions they will totally screw it all up.

Preventative measures:1. Ask the towing guy to disconnect the battery from the car and then take the battery home with you. Trickle-charge it overnight at the slowest rate possible so as not to damage the battery. If you don’t have charger then go buy one.

2. Take the keys to the E30 car with you tonight.
3. Make it emphatic that the guy shouldn’t put in another battery or do anything with the E30 car. You’ll be back.

Then, tomorrow when you go there, bring along that battery and wrenches in sizes 10,11,12 and 13, plus a vice-grip, screwdriver, jumper cables, multimeter, gloves and safety glasses.

Install and connect the battery into the E30 car while the key is off and the hazard lights and headlights are all off. See if there’s a spark when attaching the terminal. If yes, there’s a short in the wiring so then it’s time to make sure everything is off. Start removing fuses and relays one by one until you’ve resolved the cause.

Measure the voltage over the battery terminals. Then start the car again. Do not rev it. Measure the voltage again. If it’s no higher then the alternator isn’t charging the battery. Could be dirty or loose terminals, cables, wiring … a loose or broken belt, a loose clamp … not necessarily the alternator.

Let the car sit and idle for 15 minutes to see if the battery can power the car for 15 minutes without being charged.

Then turn the the E30 car off. Connect the E28 car and the E30 car battery terminals (pos to pos, neg to neg) while the the E30 car key is totally off and the E28 car is idling. That will charge the E30 car battery at the right speed. Don’t rev the E28 car and don’t let anyone else do so otherwise good-bye transmission.

Then disconnect the cables, connect the battery terminals on the E30car. Start it and do not rev it. Drive it away. Every fifteen minutes or whatever, pull off the freeway and repeat the car-to-car charging process until you get both cars safely home.

One of the service indicator lights in the instrument panel of my 1989 BMW E30 325i was on, and it needed to be reset. It’s the one titled “inspection.” I’ve just changed my spark plugs and I did the timing belt not too long ago, so by the time this light comes on again another three times or so, it’ll be time to focus on those tasks again.

To reset the light, I turned the engine off and made sure the ignition key was in the “off” position. I opened the hood and removed the cover on the diagnostic plug that sits high up in the engine compartment, near the front of the engine but to the side, specifically the driver side.

In the 1988-and-on E30 cars, the center of the plug base is a little plastic guide that looks like the Pac Man symbol, basically a circle that’s missing a triangle (shaped like a pizza slice) to represent the upper and lower jaw of the Pac Man symbol. If the lower jaw line of the triangle points to the right, then using a “clock” analogy, that’s 3 o’ clock. I found a metal-lined hole there, towards the outside of the plug base. At the 6 o’ clock position, towards the inside of the plug base, I found another metal-lined hole.

I bent a paper clip into a “U” shape and connected these two holes, then turned on the ignition key (without starting the engine). I kept an eye on the service indicator light. After a few seconds, it turned off.

I turned the ignition key off, removed the paper clip, put the cover back on the diagnostic plug, and closed the hood.

As I understand things, now the “inspection” light will stay off for 20,000 miles or so, varying somewhat based on the miles driven, and how they are driven.

I’m trying to plan things better so as to make the shop-for-used-parts process more intuitive.

The typical BMW has hundreds of parts that BMW owners might buy. For a buyer to pick these from a list is a tedious process. Some vendors, like the RealOEM BMW parts-selling website or the ZF spare parts catalog for a particular transmission, display a drawing that shows the parts essentially hanging in mid-air in their relative orientation but pulled away from each other. A simple numbering scheme in the drawing helps the buyer map an item in the drawing to the relevant detailed parts listing. This is clever and intuitive, but … still not ideal.

Why? Because the parts tend to be grouped by proximity or function, and that doesn’t always work well.

For example, let’s say you’ve driven your E30 into the back of a truck. So, now you need body parts, electrical parts, trim parts and (if the condenser was damaged) also A/C parts. When you buy due to such an event, I’m trying to enable you to find everything you’re likely to need … conveniently in one place, instead of having to go piece everything together from different paper pages or Web pages.

The ZF 5HP-24 transmission was never used on an E30, but it is a good example of what I mean. It’s a good transmission, but after 15 years the pressure regulator in the valve body has gradually worn the bore ever larger, and then fluid pressure is no longer regulated as designed and the pressure increases beyond what the clutch A drum can handle, and the drum self-destructs. Suddenly the transmission doesn’t have a functioning A clutch drum any more, and its only functional forward gear is 5th gear.

To fix this, a rebuilder needs to remove the transmission. This enables easy access for removing the torque converter, which by then probably needs a rebuild anyway due to wear and tear on it, otherwise or it might well be the next cause of catastrophic failure.

The oil pump needs to be pulled out, some seals have to be replaced in that area, and the A clutch drum needs to be replaced. So does the root cause: the pressure regulator valve in the valve body. Hence, also the oil pan gasket and filter. Functionally and as to where these parts are in the transmission, they’re quite different and the spare parts catalog shows them, accordingly, on different pages of the catalog. However, to address this very common way of failing, the list of typically needed parts really could all be listed together to make the shopping process easy for someone whose transmission has just failed in this way.

A second E30 example might be if someone buys an E30 with a missing glove box. The buyer would need the bin, but almost certainly also the hinge at the back, and the lock and latch, and possibly the clips to hold the side cable in position, possibly the two hangers, possibly the hinge-to-bin fasteners, and possibly the hinge-to-car-body nuts.  So, showing these together would make it more convenient for such a buyer.

A third E30 example might be someone who had their timing belt snap on their M20 engine.  So now, they need … probably the head, and possibly a few valves and a few rocker arms.

A fourth E30 example might be someone who is replacing the convertible top and they have a replacement canvas/plastic piece, but they are finding that some of the metal pieces on their car are bent out of shape and really should be replaced. So now, they need … things that you probably have to go piece together from multiple drawings on the RealOEM website.

Convenience in buying is what I’m trying to enable here: having parts type records grouped together in a sort of family, with that in turn linked to some or other event that drives the buying process.

Even though a family of parts type records would (of course) have multiple parts type records, the converse is true too: a particular parts type record like a front bumper might be bought for one of many reasons:

• the car was in an accident, or
• the car is generally being spruced up, or
• the car is being given a later-model-year look, or
• the car belongs to a San Francisco owner who’s tired of the demolition-derby mindset of people who have no qualms about trashing each others’ cars while parking and so a big, protruding aluminum bumper is perfect for that.

Implementing this change is no small task, but I’m very tempted to proceed.

My daily-driver E30 with the six-cylinder engine was getting bad gas mileage, and the exhaust was smoking more … not blue or bad-smelling smoke, but still smoke, or something that looked like it.

My tech waited until the car was cold, and then removed the six spark plugs and kept track of which ones went where.

By inspecting each one, she could diagnose which cylinders had which issues. One of the spark plugs’ gaps was just about closed, and one other spark plug was of a type inconsistent with the rest. All but one were Bosch Platinum plugs which are great when used in the BMW M30 engine … and not this one, i.e., not the M20 engine.  As I recall the story, Bosch Platinum was developed for the BMW M30 engine and really work well only on that, but popular demand from less-informed buyers who think the name sounds fancy wanted it for other engine too, and Bosch obliged.

My tech forced the gaps wide enough to get sandpaper in there, and she cleaned the electrodes and then changed the gaps size of the plugs to once again be to spec — good approach, to not rush out and buy new plugs all the time.  And she replaced the odd-one-out with a type consistent with the rest.

She inserted them finger-tight and then one more gentle quarter-turn to tighten. She’s wisely wary of stripping the threads in the aluminum heads such as could happen with over-tightened spark plugs.  And by making sure the engine was cold, she prevented the plug from going in cold and then expanding and being stuck.

I started the car and it ran better than it has in a long time, yay!

My E30 daily driver needs an oil change again, and I now have a nice warm place and a pit to make it downright pleasant to change the engine oil, so one of our brilliant techs did that today. She did some reading up on what the correct weight is and reminded me of the importance of choosing the right oil.

For example, if the factory specifies 15W50 weight for this engine, this means it’s a multi-grade oil with the “15W” being the cold-start temperature.

The lower the number before the “W”, the more runny the oil is at a cold temperature. At a cold temperature, “runny” is good for that number.

The higher the number before the “W”, the less runny the oil is when it’s cold. So, a too-high number means that when you first start your engine, the engine oil pressure might be high enough to damage things and yet the engine internals aren’t being lubricated with oil until later when the engine warms up, and until then you have something that’s more like honey or molasses as to viscocity and so your internal engine parts are wearing very rapidly.

I often park my E30 outside and sometimes it gets single-digits cold here, as in colder than 10 degrees Fahrenheit, so I’d be unwise to go buy engine oil with a higher number before the “W” such as 20W50. If anything, I should go lower on the first numbers, such as “10W”.

As to the number after the “W”, that’s how runny the oil is once the engine warms up. So, at a given temperature, oil with a “50” after the “W” will be less runny than oil with a “40” after the “W”. In that context, too-runny is not good, so a higher number is good.

I would prefer to read the official BMW opinion as to what grade oil I should use, and I haven’t seen that yet, so hearsay and common sense are my fall-backs. On those premises, 15W50 does sound about right. If anything, because I live in the cold North and it IS the middle of winter, I could even go lower and still be OK.

I went to Autozone and tried to find 15W50. They didn’t have any, but they did have 10W40. Those are slightly lower numbers and that’s OK since it is colder weather now. So, that’s what I chose, along with a Bosch engine oil filter.

The oil drain plug is a bolt with a 14mm head, and there is also a washer as a gasket between that and the pan.

My favorite car to drive as to reliability, which means all in all, is my 1989 BMW 325i. I love this car, even though:

• The door has had issues and by now it doesn’t lock any more
• I tried to fix that and the interior driver side paneling is now non-existent
• The air conditioning compressor stopped working long ago
• The passenger seat had a pokey spring in it until I replaced it with a pretty other E30 unit but totally in a non-matching style and color
• The center console is gone; I forget why
• The temperature gauge shows that the car is ice cold until I’ve driven it for 10 miles, and then suddenly it springs to life
• The car is probably running insanely rich
• The coolant warning light gets upset when I go around a corner quickly
• Coolant seems to keep vanishing
• The rear suspension squeaks like crazy
• It looks like a front seat passenger had swallowed a lot of dark paint and then threw up on the beige carpet
• The top plastic of the instrument cluster is broken, due to me trying to hotwire the car when its ignition switch died
• The big trim piece underneath the steering wheel is missing for the same reason
• It leaks oil
• The clear-coat is flaking off everywhere
• The dash is cracked

My little E30 just keeps going and going and going. I change the timing belt regularly, service the transmission regularly, change the oil, and it just keeps on being 100% reliable.

My friend has been driving BMWs since the early 1980s, and he currently owns two V-12 BMW 750iL cars. He describes his frustrations as “death by a thousand paper cuts.” Not that my E30 is dying as long as I cheerfully tolerate its indiscretions. It just keeps going. I love this car.

Sometimes, compliments are earned by contrast. And yes, that’s the case here. Don’t hate me, but I recently bought two 2000 Audi A6 Quattro rocket-ship cars with the 40-valve V8 4.2 engine and 5-speed Tiptronic Porsche-designed transmission. Compared to my E30 they’re so advanced it’s like they’re from outer space. And they both have dead transmissions. As in, very expensively dead. Which mean, within my budget, they are unfixably dead.  That’s fine because I knew that when I bought them, and the prices reflected their condition. Maybe one day I’ll figure out how to fix them affordably. Until then, I smile when I think about the dead Audis and I drive my 11-years older-yet E30 and feel its little transmission shift perfectly.

There’s an added bonus; I tend to often get lost in thought, and it’s happened more than once that I forgot where I’d parked or what I was driving that day (I do have three other cars licensed and insured), and then I came across this lovely bronzit-colored E30 in the parking lot, and I thought “ooh, what a pretty E30” and then I realized: “hey, blondie, that’s your own car.”

To cart my used parts around, I have:

• A Ford E150 van
• A Volvo station wagon

And yes, they both drive, but they both need some work done.  And so for my latest parts run, I drove my trusty 2-door E30 1989 325i.

Problem is, if that’s a problem, I found an AMAZING deal at one junkyard about 120 miles away from my shop: a dead 1987 325is with really pretty seats in great condition.

I also wanted to buy many other cool things from that E30, not just the seats. That included bulky stuff that, together with my tools and the overnight luggage for two people (myself and my assistant) pretty much filled up the trunk.

Could I make my little E30 swallow two entire passenger seats, with seat slides, plus the rear seat seat-back plus the rear seat bottom? No. But, my assistant could.  Bonus: after I wrapped the seat slide ends in old clothes and loafers to surround the sharp edges, the trip back was made successfully without the pretty surface of the seats being marred or torn.

Success!

The passenger seat on my personal E30 has long since been a pain in the butt, literally, for its occupants. One of the springs is poking through the upholstery and so whoever sits on the seat will get scraped or gouged unless they cover the area with some thick fabric such as a towel.  Since I used to have passengers approximately 0.001% of the time, replacing the seat hasn’t been a priority but the seat is, or I am, becoming more popular so perhaps it’s time to do something about it.

And so off I went to the local junkyards, and I found a nice seat with matching colors in a 2-door BMW E30 like mine. Yay!

The previous owner had allocated a significant amount of money and effort to his sound system, judging by the modifications to the car. I sometimes wonder if, had that money been diverted to preventative maintenance instead, the car might not still be on the road instead of languishing in a junk yard.  Choosing to neglect the timing belt is a classic mistake that E30 owners make, as one example.

Anyway, this car had some expensive-looking aftermarket sound system cable running from the passenger front seat down the center and under the back seat into the trunk. Under the passenger front seat was also a massive speaker box.  I tried to remove it from under the seat, either from the front or the back, and … no go.  I gather the installer had removed some or all of the seat anchor points, shoved the speaker under the seat and then bolted the seat down again.  Not that the speaker was attached to anything; it was loosely lying around under the seat.  Odd.

Anyway, when the time came to remove the seat, the seat slide was already all the way back, and this allowed open access to the two forward plastic covers over the 17 mm fasteners, and to the fasteners themselves. I removed them, quickly and easily. The next step was to slide the seat forward so as to enable access to the rearmost two 17 mm fasteners, but … the seat refused to slide forward.

My assistant pointed out that there was a problem with the rod that connects the master side slide clutch, the side where the  lever is, to the passive side.

I presume that the sound system installer had disabled the rod so as to make room for the hug speaker bouncing around the seat … not the sort of trade-off in functionality that I’d have chosen. Anyway, to each his own.

As a consequence of the disabled rod, only one side’s slide disengaged when I pulled the lever up.  This meant that I needed to reach under the seat to the passive side and manually work the little side clutch while with my other hand pulling the lever up on the other slide, and then with my third hand I’d push the seat forward. Not a perfect plan but it seemed worth a try. My assistant had already removed the driver seat, so I looked at its slide mechanism to see how the mechanism worked, and where I needed to push.

The problem is that I couldn’t easily reach under the seat; it was down very low.  I remembered that E30 seats have a height control, so I activated that with one hand, and with the other hand I pushed the seat bottom upwards. The problem is that my finger was at the time in an opening where two pieces of metal form a gap that closes as the seat rises, and my finger got squashed. Oweee.  The two pieces of metal had sharp enough edges that, had I done this more vigorously I might have crushed the bone or cut the finger clear off. Fortunately I had reacted quickly and had stopped the upwards pulling motion just in time.

Not feeling very happy any more, I reach underneath to the slide clutch and found that the area has some sharp metal pieces that rubbed and scratched the skin off my upper arm. I kept going and finally got the job done well enough to where the seat could slide forward, but I wasn’t all too happy with the extra fee I’d ended up paying in personal pain.

Even so, I am now the proud owner of an entire set of front and rear E30 seats.  And, for the record, these all could fit onto the existing back seat of m E30, after removal of a headrest or two, and protecting the seat face from damage from the slides of the other seat.  Success!

We come across many E30s in the course of our business, and many no longer have a tool tray in the trunk lid. Perhaps you have just bought your E30 and the tool tray is missing.

This design of tool tray is also used on some of the E28 5-series cars — not the high-end models, just the 528e with the M20 engine. The larger-engine cars have a bigger tool tray, too.

The tool tray hinge area attaches to a metal brace in the trunk lid, with two Philips-head [TBD: confirm] sheet metal screws. We can include these screws with your order, if you need them.

It’s rare that the foam rubber in the trunk lid is missing but maybe yours is filthy. On principle we do offer these too though the glue makes it hard to remove the foam from the trunk lid.

The latch of the tool tray is a plastic knob with an integrated washer cast-in. The hole in the tray is oval, not round. The washer is angled and has a gap so the factory must have assembled this by holding the knob at an angle and then screwing it in. We have sold at least one knob by itself, without the tray, so yes, we do offer them.

A plastic strap keeps the tool tray from yawning open too wide. We offer the strap too.

We offer the tray without the knob or strap if you might enjoy saving a few dollars by wrestling the strap and knob out of your presumably broken or rust-stained tool tray, so you can re-use these. The BMW part number I see on the tool tray is 1128 911.0.

For those who don’t want the hassle, we also offer the tool tray with the strap and the knob.

We often see marks left by rusted tools, on these tool trays. I used to wonder why until I bought an E23 735i. Its trunk lid, on the inside, with all the tools, was always wet with condensation — even though I live in the middle of the Nevada desert. That would explain the problem.

We clean the rusty marks away as best we reasonably can but the tool trays we offer might still have some black stuff on them — but typically not easily-visible rust or rust stains. There is a small vent hole, presumably to equalize air pressure within the tool tray and the outside world. Sadly, we find it difficult to clean this part without getting water into the vent hole.  Fortunately, in the dry Nevada climate, it’s likely to dry out fairly quickly.

On the tools, we like to use Naval Jelly.

As for the original BMW tools, they are becoming quite rare and they’re priced accordingly. We do sell the individual pieces, though:

• Open-ended wrenches, sizes 8-and-10, 12-and-13, and 17-and-19.
• Pliers
• Spark plug wrench
• Rod or pin that presumably helps turn the spark plug wrench
• Screwdriver
• Allen head tool
• White plastic manual window crank

I recall a joke where a huge, mean-looking guy, probably a former boxer, approaches the produce guy in a grocery store. The store sells half-watermelons, nicely wrapped in plastic, but … this customer wants to buy half a cauliflower. Wait, what? The store doesn’t sell half-cauliflowers, says the produce guy. The customer insists and gets more and more angry. Eventually the produce guy sighs, and tells the customer he’ll go ask the manager. Shaking his head, he walks into the back and finds the manager, and says “you’re not gonna believe this, but some damn fool out there wants to buy half a cauliflower.” He sees the manager’s face looking aghast and looking past the produce guy, and … yes, the customer had followed the produce guy and was standing right behind him.  So, the produce guy smiled, turned, gestured to the customer and said: “… and this gentleman wants to buy the other half. May I proceed?”

That’s sort of how things work at our little business.  We might think we have things broken down to an atomic level where nobody would want to buy a sub-component of a particular part, and then someone does. Unlike the produce guy, however, we’re delighted when something like that happens.

Let’s use the glove box as an example. It has a latch on it.  Some customers will want just the latch, some want the glove box without the latch, some want both.  So, we happily sell every combination and it’s all optimal because this way our customers only spend the money on what they really want, not anything extra. Someone else can buy that.

I really thought the tool tray that goes into the trunk lid of an E30 would not be a part that would be broken down more, but a new customer wants to buy a glove box latch, and he also needs the tool tray knob — just the knob. The knob would fit nicely in the same small box as the latch, but if I have to mail the entire tool tray also, not just the knob, it’s a bigger box, so the postage costs more, plus it’s more of a hassle for the customer to remove his old tray and transfer his tools to the new tray.  Besides, he’d also be spending extra money on buying the tray with knob as opposed to just the knob. Him wanting to buy just the knob makes perfect sense. Lower price, lower postage, less hassle.

Problem is, until 2 a.m. this morning I didn’t know how to remove the knob from the tool tray, but my new assistant figured it out for me, yay! So, yes, as of today, I do sell the tool tray knob separately for those who want it. The customer was happy, and placed the order … a nice “win” for everybody.