February 28 2006   Story: By: Bryan Joslin

Winter in Chicago is a hard time for car enthusiasts. Not that we typically get buried in snow or experience long bouts of sub-zero weather. It’s just so damn long, and you never know what the weather will be like from one day to the next. Needless to say, progress on a project car can come to a screeching halt, as mine did.

Still, the winter has its own demands, the most noticeable one being reliability. A quick once-over before the start of any severe weather revealed a few issues that needed attention, among them a bad #4 plug wire, a failing timing chain tensioner, and inoperative reverse lights. And simply keeping the car on the road during the cold months was going to require more than mere all-season tires.

First order of business was to replace the noisy timing chain tensioner. Though the timing chain arrangement in the M42 engine is more reliable than a toothed belt, it requires a hydraulic tensioner to keep the chain taut. The tensioner fitted to M42 engines commonly failed, leading to a loud, gravelly noise that often makes the little 4-banger sound like a diesel. Unable to handle the racket, I replaced the part with an inexpensive aftermarket item, assuming it would be better than nothing, at least for a while.

I was wrong. Almost immediately, my new tensioner was making nearly the same noise that the old one did. The solution may be in upgrading to the part used in the subsequent M44 engine (BMW part # 11 31 1 743 187). Of course, the problem could be deeper than this as well; this problem combined with noisy lifters point to the possibility of a weak or failing oil pump. A more thorough investigation is in order once the weather improves, when several oil leaks will also be addressed.

A fall cleanup of the engine compartment revealed more than just the oil leaks. Liberal amounts of engine degreaser and water were used to remove the film of crud from the engine compartment. Doing so led to the car running on only three cylinders. With the engine still running, each plug wire was removed and reinstalled individually, causing the engine to run on just 2 cylinders until the wire was pulled from the already-dead cylinder, in this case the fourth one I checked, cylinder #4.

Once the engine was shut down, a quick look at the coilpack showed that the terminal on the #4 plug wire had corroded off under the boot. The humid conditions under the hood caused arcing of the wire and the resulting misfire. This didn’t present a problem once the engine compartment dried out, but the only real solution was to replace the wire. A full set of new wires and fresh plugs was ordered from BMP Design, taking care of both the damaged part and some general maintenance in one shot.

When I picked the car up earlier last year, I discovered that the speedometer, and accordingly the odometer and fuel economy gauge, was not working. There are three main components to the speedo on the E30- an electromagnetic induction sender mounted in the differential, the speedometer assembly in the gauge cluster, and the wiring between them. It’s not uncommon for the sending unit to fail, and since it’s easily accessible from under the car, I decided to go ahead and purchase a new original part at the dealership, to the fairly modest tune of about $25. Within five minutes, the old was swapped out for the new. A quick drive around the block confirmed what I feared- the problem was deeper than I thought.

The wiring and terminal connection were examined thoroughly, and no breaks or other damage could be found. The next step was to disassemble a fair portion of the dashboard to remove the instrument cluster from its perch. Once this was out, the speedometer was separated from the assembly for a closer look. Failed solder points are common on E30 speedometers, so I combed the printed circuit board for evidence of a broken joint, once again to no avail. Just as I was beginning to assume the problem must lie somewhere in the wiring, a certain nightmare to fix, I noticed a burnt resistor on the back side of the speedo’s circuit board. The good news was that I had most likely found the problem; the bad news was that it would be virtually impossible to fix, necessitating a new speedometer.

The reverse lights were another electrical anomaly that I inherited from the previous owner. Even though I had replaced the fuse, the backup lights refused to shine. My first assumption was a failed reverse light switch, but in researching the problem someone suggested that I check where the wiring harness enters the cockpit at the base of the shifter. Sure enough, two wires that lead to the switch on the transmission were pinched together between the dust boot and the shifter opening in the floorpan. The insulation had been compromised, causing a short (and a blown fuse) when the bare wire made contact with the metal floor.

The wiring was pulled free from its pinch and the cuts in the insulation repaired temporarily to prevent further shorting. The long-term solution is to add a little extra length to the two wires that come from the underside of the car so that they don’t get drawn back into the opening and damaged again. This will be done once the weather turns warmer, or when my new garage becomes functional, whichever comes first.

Without a limited-slip differential, the all-season 14-inch tires on the 318 lacked the ability to put down even modest power on salt-slicked winter roads here in the Midwest. A more appropriate set of shoes was in order, and the Tire Rack answered the call. A set of Dunlop Graspic DS-2 winter tires was ordered in 185/70-14 size, mounted to a set 14x5.5-inch steel wheels. This solution is more economical than swapping tires on and off the stock wheels every season. It’s also less expensive than buying new alloy wheels for the winter tires, if not as attractive.

The “steelies” can be ordered in traditional Henry Ford fashion- any color you want, as long as it’s black. For reasons I don’t fully understand, some enthusiasts find the black winter wheels something of a functional fashion statement; the black steel wheels are supposed to be seen as a badge of honor, signifying to other drivers that this car is indeed equipped for winter. I’ve never been fond of the look myself, finding it a little unfinished. Instead, I immediately masked and painted the wheels silver, using an aerosol wheel paint from the local auto parts store. A couple coats provided adequate coverage.

But to finish the wheels completely, I used a set of inner wheel caps from a Volkswagen (VW Part# 871-601-171) to cover the wheel hubs. These finishing caps are held on by the shoulders of the wheel bolts as they are tightened. Although these currently display the embossed VW logo, the plan is to cap them with a set of replacement BMW emblems.

With the project finally gaining momentum, it was important to find out just how healthy this motor was before going forward with any tuning or performance mods. A trip to Genesis Racing & Development (GRD) in Naperville, Illinois, for a stint on their Dynapack wheel dyno would answer a lot of the questions I had. Hopes were pretty low for the 15-year-old Bimmer, with mwerks forum members stabbing their own guesses at its output between 95 and 120 horsepower.

In the end, the old mill pumped out 104.7 horsepower at 5700 rpm, and 105.8 lb-ft of torque at 4650 rpm to the wheels. Considering the factory figures (at the crank) were 134 horses at 6000 and 127 lb-ft at 4600, all indicators are that the motor is healthy enough to move ahead with upgrades. As mods are performed, we'll go return to GRD to see our gains (hopefully).

As the weather starts to tun around (and now that I have adequate garage space), the project will start moving along much more quickly. BMP Design has offered to help out with the project as well, speeding up the process. Next month we'll take care of some basic cosmetics before moving on the real work. Stay tuned.