Bad Timing
by Charlie Burke
Bimmer, Mar 98 newsletter
Boston Chapter
On a recent trip home from the office, I noticed the fuel reserve light had been glowing a little too long. So into the next gas station I went. Within seconds of pulling the fiver back into the flow of traffic, the engine sputtered, lost power and quit. Safely making it to the roadside, I thought, that's funny. Not ha-ha funny, but peculiar funny. This car's been great-a testimonial to BMW's enduring engineering. Maybe the tank ran dry just before topping off. It's never happened to me before-it's a long shop-but maybe? The reserve light was on for quite a while and the range display had been flashing dashes for miles. A few cranks of the starter should reestablish fuel pressure. Probably no problem at all. Yeah, right.
As the engine cranked, the grim sound of a compression-less engine sent quivers up my spine. I knew what had happened. I was all too aware of the consequences. I was suddenly despondent. The rubber band driven baby-six was very broken. I had run out of borrowed time. The timing belt was now a discontinuous strip of rubber.
I can't believe it happened to me. I'm pleading the Twinkie Defense. Too much refined sugar clouded my judgment. I was too busy. It was cold out. I didn't think it was time yet.
I've been known to wax eloquently, often in public gatherings, on the virtues of proper BMW maintenance. I served time as the technical editor for the Boston Chapter. I'm regularly called upon to help troubleshoot logic-defying automotive maladies. I've authored a few books on the subject. I've practically memorized BMW's maintenance schedules, not to mention an ASE Master Technician certification. I simply should have known better.
I must admit, the cobbler's son has leaky shoes. It is now my duty and onus to offer up my repentance and publicly state my shame and dishonor. The belt should have been changed ahead of the brake job on my sister-in-law's Trooper, the rear wiper motor on my friend's VW Fox, and the seat memory and instrument cluster on my brother's 735iL. I should have made the time. I give you my word; it'll never happen again. No, never is a long time. It won't happen again too soon. Promise.
Lots of engines use rubber-reinforced belts to drive their camshaft(s). On most cars, breaking the belt is no big deal. Worst case is you'll get stuck on the side of the road. Tow the car to the shop, spend a relative few bucks, and you're on your way. Nearly painless. Volkswagen doesn't list a replacement interval for their belts. A lifetime belt? Exactly. You replace the belt at the end of its life: when it breaks.
Breaking a belt on a BMW small six is a bad thing. When the belt gives up the ghost, the camshaft stops dead, leaving lots of open valves sticking helplessly into the path of the pistons. Crash, ping, clink. Nine of my twelve valves became instant casualties.
After a few cold nights in the garage, the cylinder head was off. The old shredded belt was in sorry shape. It's hard to imagine how it lasted so long. The only thing that kept this belt on was its fear of getting strangled by the crankshaft.
BMW says to change the belt at 50k. This belt must have had twice that on it. In my own pathetic defense, I honestly didn't know how many miles were on the belt. I'm too embarrassed to find out now. I desperately needed a plan. No one needed to know this happened. This didn't happen. Hide the car in the garage. Brilliant. My neighbors and colleagues won't suspect a thing. I'll make like the car's going away for the winter. I already own more cars than my bank account can handle. There are ready spares in the automotive stable. The E32 seven should work well. This is starting to feel OK. I'll then make it like I changed my mind; a well known trait of mine.
To make a long story short, it turned out to be a big job. Mind you it was the cold season in New England and the garage is not heated. New valves, valve guides, and machine shops services was the de rigueur. The valve seats and valves had to be cut, the head resurfaced, and each valve hand-lapped into place. Add in the gasket set, a new water pump, timing belt, tensioner, coolant, oil change stuff, and way too many hours of labor. You get the idea. All because I didn't take time to change the stupid belt; a job that can be done in an afternoon. I even had all the parts in the trunk. A valuable lesson was learned.
There, I've confessed and it feels better. Just between you and me, I decided to take the fiver out of hibernation. It's running great.