Mike Miller recommended BMP Design for its aluminum thermostat housing. BMP also has singl
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.
Sir Tools manufactures a very high-quality 32mm wrench and water pump pulley holder needed
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.
PIAA, an Oregon-based company that should know a thing or two about rain, supplied a set o
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.