Project 325is Part 2: Fixing what's broken(or might break soon)

Project 325is was introduced in March. The goal is an excellent all-around daily driver, comfortable on a 40-mile commute yet fun to drive and able to perform through extended track lapping sessions in triple-digit weather. The foundation for both those objectives is reliability, so this installment is about the basic stuff: updating maintenance on a 100,000-mile car and looking after standard E36 trouble spots. Nothing cosmetic has been done yet, because a scraped bumper will never leave a person stranded.

My treatment of a "new" used car stems from my experience with a Fiat in high school. I expected to have to work on it regularly but hardly ever did, because the seller had taken the time to replace ignition parts, belts, hoses and other details that could wear and decay. If that car could be made reliable, applying a similar program to every car is a good idea.

There is an economic balance to be struck. Paying someone else to do the work may be expensive enough that one would be better off just buying a newer car that needed less of it. I do as much of my own work as possible, partly because I can't afford to pay someone I trust to do it right and partly because I am a control freak and must know exactly what was done and how. I have also developed a deeper appreciation for the engineering of the car. Most normal service procedures are almost trivial, while less usual tasks can be a real bear, requiring three unrelated items to be removed before accessing the desired parts.

It's always best to use parts from BMW or OE suppliers such as Bosch, Mann, Continental and Mahle whenever possible. I worked with Import Parts Specialists, Inc., a supplier of original equipment parts and accessories for many European marques. IPS opened in 1993 and has provided online ordering since 1996. It even stocks some basic upgrade lines such as Red Line Oil and Zimmerman cross-drilled brake rotors. Of all the companies involved with Project 325is so far, IPS provided the most prompt service with the least follow-up required, and its pricing is impressive.

Start with filters: air, oil, fuel and the cabin air microfilter. Electrical parts come next: spark plugs and the oxygen sensor. The reduction in fuel smell at the first cold start confirmed the latter was needed. The fuel injectors were cleaned by R.C. Engineering to ensure everything was without fault and arrived back at the office three business days after being mailed. The calibration report showed the flow initially ranged from 161-169cc/min, with four having a "good" spray pattern and two dripping. After cleaning, the flow was 169-171cc/min, with all injectors having an "excellent" pattern. That's enough to matter when we start splitting hairs on the dyno. evosport, the performance shop that has been so helpful with Project M3, will do a compression leak-down test as well, but changing deadlines prevented that from happening yet.

The wrong fluids can lead to problems. I followed the advice of Mike Miller, full-time BMW technician and author of the E36 buyer's guide in the March 2003 issue. Mike said to use only BMW coolant, as other brands may contain chemicals that can cause engine damage. Mike likes Red Line synthetic oils, recommending D4 ATF for the transmission and 75W90 for the differential. The engine oil was already changed with Castrol Syntec synthetic; if it's good enough for factory fill on the E46 M3, it's good for a 1993 325. The brake system was flushed with DOT-4 fluid.

The M50 engine's cooling system accounts for two E36 trouble spots. BMP Design supplied a cast aluminum thermostat housing to replace the failure-prone plastic one and a water pump with a cast steel impeller. Early cars used a plastic impeller that is efficient but can loosen on the shaft, causing overheating and, possibly, serious engine damage. BMP also has single-part-number ordering of all the coolant hoses for any BMW. Don't forget to drain the block, and have a new 14mm crush washer ready to seal the plug. Continental drive belts finished off the front of the engine.

The E36 chassis works its suspension bushings hard. The "lollipops" at the rear of the front trailing arms had recently been replaced, but the rear trailing arms' forward bushings were badly worn. I replaced them following the instructions on Bob and Patty Tunnell's website (www.tunnellracing.com), though I didn't find the site in time to order the bushing for a '96+ M3. It took about four hours to change both sides, with the car already on stands for the other work. For less than $30 in parts and tools, the car was transformed.

While you are working in the trailing arm attachment area, inspect the body itself very carefully for any sign of cracking around the bolt holes, an extremely infrequent but disastrous occurrence with E36s. BMW has stated that it is not aware of any cases of the failure in which the car was not taken off-road, either by accident or on purpose. Mike Miller has seen a few of them and is freaked out enough about the results to make it his number-one pre-purchase check on any E36. Project 325is' mounts appeared to be in perfect shape.

Missed shifts due to engine movement are another E36 nightmare. The rubber in Project 325is' engine mounts was visibly deteriorated, so they were replaced. By loosening the nuts on one side and removing the nuts on the other, the engine could be tilted with a hoist just enough to slip the mounts out and back in, one side at a time. Rock the engine back and forth to settle the mounts before torquing them to spec.

Further reducing engine play are UUC Motorwerks transmission mounts and enforcers. UUC Motorwerks appears to be an engineering-driven company, dedicated to geeking out on the subtle details that make all the difference in a car--my kind of people. UUC says it started with the 320i mount that is a standard BMW upgrade and worked with a vibration lab to develop mounts that maintain the vibration damping and deflection properties of the 320i mount and incorporate minute changes to optimize them for use with UUC's Tranny Mount Enforcers. UUC claims no increase in vibration from this system. My initial drive revealed vibration, but it decreased significantly in just ten miles, so we'll see how the break-in goes. While I was at it, I installed UUC's Big Boy clutch pedal stop. I've always pressed the pedal to the floor during shifts, so I expect this will save just a little bit of time with each shift. I haven't changed the worn, stock shifter yet, but much crispness was restored with the mount changes; I may decide it's fine as-is.

While not normally a service point, Project 325is' exhaust was history. It sounded great below 2500 rpm but was otherwise pretty lame. When removed, it shook like a can of sand. I checked european car's January, 2003 M3 exhaust test; Supersprint's units performed well, sounded good and had flawless fit, even if they didn't make the most power peak or weigh the least. Other absorption-style silencers I've used are quiet around town but grow throaty when the car is driven hard and they heat up: perfect.

Supersprint's black system with straight tips was still sitting in european car's storage dungeon, and I found it was actually made for a 325/328. Since it still achieved a small power increase on a 3.2L M3, it seemed like a great way to go for Project 325is. The rear silencer's rubber mounting brackets are another E36 weakness, so plan on replacing them if they have more than about 30,000 miles.

Tools
Having the right tool for the job makes working on cars easier, faster and more pleasant, and doing the work oneself usually saves enough money to justify the purchase of any special tools required.

The first tool any European car owner should consider is a service manual. Bentley manuals are said by many to be the best. I had used them only briefly before this project. I found the "BMW 3 Series Service Manual: 1992-1998" to be alternately helpful and frustrating. Generally, it guides one through whatever task is at hand in a safe, careful manner and occasionally addresses a concern such as replacing the water pump only with one having a metal impeller. Its detailed schematics allowed me to track an electrical gremlin. I would be a lot shyer about digging into the car without the manual looking over my shoulder. However, I have also been surprised at the number of times it has been incomplete, unclear, or (rarely) apparently just plain wrong about some detail. I've consulted Mike Miller and a local BMW specialist to find the "correct" way to perform seemingly simple tasks. Despite its flaws, the Bentley manual for the E36 has been very helpful.

Sir Tools was among the first companies to be highlighted in Tool of the Month (December, 2000), and I turned to it again for several items needed for the tasks outlined in this article and still to come. They are all high-quality, black-oxide-coated, designed and manufactured by Sir Tools for professional technicians and serious enthusiasts.

Reading List
Bentley Publishers recently introduced "Complete Roundel," a set of eight CD-ROMs, covering 1969-98. Roundel, as the voice of the BMWCCA, is respected for its marque-obsessed levels of technical detail as well as many columnists and other coverage of things BMW not wholly unlike what may be found in european car. I haven't spent a great deal of time relaxing by reading old stories or digging in for the historical aspects, but I did sit down one evening with a list of problems and questions I had with Project 325is. I found BMW's official statement about the rear trailing arm body mount issue but am fairly certain there will be information in this project series that was never in Roundel. So there. Still, without the "Complete Roundel" search feature, there's no way I could say that, and I did find excellent technical articles on other E36 issues. I'm not about to cancel my current Roundel subscription. Perhaps its greatest advantage is that the "Complete Roundel" set takes up less shelf space than any other back issue collection. It holds 30 years in less volume than two issues of european car and is a great way for the new or seasoned BMW lover to catch up on decades of experience and passion for the marque.

What's Next
Now that Project 325is is sorted out and freshened up mechanically, the next step will be either complete overhaul and upgrades to the braking system or sorting out the cosmetics, depending on which can be pulled together sooner. Personally, I never bet on the paint sniffers.