With the Suburban now finally behind me (actually, it’s not behind me, it’s literally all around me; it’s got 5,500 pounds of steel, and four-wheel-drive, and decent heat, including heated seats—all the nice winter things my Z3 lacks), I can finally work on something else.
Folks are often surprised when I say that I own a 1987 E30 325is. I bought it about a year and a half ago. It’s Zinneberrot with a tan sport interior, stick, 144,000 miles, very original, very good condition. I haven’t written about it much because I haven’t tangled with it much. It’s the only car I’ve ever bought purely for investment. It’s been largely just sitting in storage; I doubt I’ve driven it 50 miles since buying it and towing it home from central Vermont. I just haven’t developed the kind of relationship with it yet that comes from ripping it apart.
The car was owned by a mechanic who worked mostly on vintage American iron. After we made the deal and shook hands, and I loaded it on the trailer, I asked him why he was selling it. “Well,” he said, “it was my wife’s car, but she wasn’t driving it, and garage space is short.”
“I understand that,” I said.
“Plus,” he said, in one of those flawless moments when two people look at the same thing in two completely different ways, “I just don’t see this car appreciating.”
I didn’t say another word.
The car appears to be in very good shape; but, as is often the case with folks who do their own work, there was no folder of receipts with the car. The seller said that he thought he’d done the timing belt “a few years back,” but as someone who thought he replaced the water heater “a few years back” only to find, when it blew last week, that it was ten years old, I know that this sort of estimate, even when performed in good faith, is notoriously unreliable.
Since six-cylinder E30s have the M20 engine—the only BMW engine with a timing belt instead of a chain—you really, really don’t want to be wrong about the age of the belt. Most engines that have timing belts are non-interference engines, so named because the valves and the pistons never occupy the same space in the cylinder bore. If a timing belt breaks in a non-interference engine, the car immediately loses all power and coasts to a halt. You scratch your head, call a tow truck, they haul it to a generic Foreign Car Repair Shop, and three or four dollars later, you’re sent on your way.
On an interference engine, however, things can interfere with each other. The valves open into the space occupied by the piston when it reaches apogee; the timing system whisks them back to safety before the piston arrives. Of course, the timing belt provides the synchronization necessary to make sure that the valves are fully closed when the pistons come up.
But when the belt breaks, that synchronization is gone, and some of the valves are just hanging there waiting for the pistons to crash into them—which is exactly what happens. If you’re lucky, it happens at engine startup and bends the valves, and you cry—but you don’t go full-on Luke Skywalker hearing I am your father.
If your luck is neutral, the pistons snap the heads off the valves, and the valve heads embed themselves in the piston crown, but the block survives.
If you’re unlucky, the result is a grenaded engine.
Timing-belt maintenance is not the kind of thing you want to be wrong about. The recommended maintenance schedule for the E30’s timing belt is 60,000 miles or four years, whichever comes first. Ironically, if the car is rarely driven, it’s recommended you change the belt more frequently, due to the fact that the belt can take a set and lose its flexibility.
Now, I had three E30s back in the day—a nice 325iX, a ratty but fun ’vert, and a 325e that I bought for peanuts due to a huge dent in the rear quarter and the fact that the clutch had dropped all of its lining, rending the car literally immobile—but it had been nearly twenty years since I’d changed a timing belt. I read up on the procedure, ordered the parts, and began to tear the E30 apart.
That’s when the whole Suburban brake-line thing erupted.
But changing the timing belt on an E30 is pretty straightforward. You pull out the radiator, pull off the fan, remove the belts for the power-steering pump, alternator, and air-conditioning, and then pull off the belt covers and the crankshaft harmonic balancer.
The biggest issue was the compressor. For some reason, it had a belt on it that was one size too short, making it so tight that there was no way to remove it without cutting the belt or unbolting the compressor from its mount and angling it to get the belt off. Oddly, however, this worked out for the best, because in having to pay this much attention to the compressor, I found that its clutch was junk. And when I undid the fittings and hoses and yanked the compressor out and turned it upside down, I found that it was completely dry of refrigerant oil. I found a used E30 compressor locally on Craigslist for $20.
When I finally exposed the timing belt, I found that it looked new. M20 guys say that when you change the timing belt, you should also do the water pump, as you’ve just exposed it. And when I grabbed the hub of the water pump, it, too, appeared perfect; when I rocked it, there was zero play.
So what do you do?
Since a Continental timing-belt-and-tensioner kit is only about $40, and a Graf water pump costs about the same, and since the goal was prophylactic maintenance anyway, it seemed like false economy to simply put it back together with the same parts. I put in an order.
That’s when Hurricane Suburban hit.
So now that that adventure was finally behind me, I did a morning’s organization, making sure that the E30 parts were together and correct. And the first thing I found was that the bearing in the brand-new Graf water pump was worse than the one from the E30.
(Next week: It came apart, ergo it must go back together.)—Rob Siegel
Rob’s book Memoirs of a Hack Mechanic is available through Bentley Publishers, Amazon, and Bavarian Autosport—or you can get a personally inscribed copy through Rob’s website: www.robsiegel.com.
