While it always looks great to be the top gun in a repair shop, that job is no doubt the hardest and most stressful. He was the one everyone would come to when they couldn't fix an ailing Benz. He always had his nose in a book or was on the phone and was constantly being bombarded with all kinds of problems that everyone from the technicians to the owner would dump in his lap. Today, the problems went all the way back to his service bay.
This particular job wasn't going well. The 450SEL was giving him fits. After a dozen visits to his bay, it was back again. It had a drivability problem that was intermittent. On the road, the engine would suddenly shake and drop about half of its cylinders. It was impossible to duplicate the problem in the service bay.
Once again, Chuck stood in front of the engine, peering down at it for some kind of inspiration, his fingers buried in his thick black beard. He was thinking -- thinking of all the things he had installed in the "albatross" already.
After the third visit he dubbed it that name after the great sea bird. Now the car hung around his neck, and the owner was getting involved and the pressure was on.
- Chuck replayed in his mind the parts he had replaced in this 1971 MBZ D-Jetronic EFI V-8 4.5 liter. There were two computers, a pressure regulator, an intake, air sensor, eight injectors, engine harness, throttle switch, coolant switch, and distributor trigger contacts. There he stood, hunched over like the weight of the world was on his shoulders. First, he had gone after the trigger contacts. This was the Achilles-heel of all D-Jet systems. The quadruple set of trigger points ride on a cam below the breaker plate in the bottom of the distributor housing. Every time one of the four sets opens, two injectors are fired. The point material tended to get covered with soot created by crankcase fumes escaping up the distributor shaft. If the fumes didn't get to them, their tiny contact surface tended to pit and make poor contact.
The car seemed to run better each time he worked on it, only to return a week or so later for the next fix -- this time it was the intake air sensor. In D-Jetronic, the "D" stands for the German word "druck" meaning pressure. The intake manifold was connected by a large braided hose to the intake manifold pressure sensor, a precursor to today's MAP sensor. This sensor was prone to filling up with oil from the distillation of crankcase fumes. After a while it would literally fill up with a gummy, oily slime that inhibited its operation.
The injectors were next. It seemed reasonable. The car had almost 100K on the ticker. While he was at it, Chuck pulled and resealed the intake manifold and throttle body --just for good measure. Topping it off with all new fuel hoses made the job take all day. Once again, when done, the car ran great. And once again, it was back in a week with the same complaint. He went on replacing item by item, following the manufacturer's suggested guidelines.
The last item in the chart was the computer. When in doubt, put a computer in the car. It's the mechanic's creed. The infamous automotive "black box is not very well understood. When it fails, it doesn't shout "replace me." Mechanics are prone to blame it first. Chuck had to wait for another week and this time the car stayed in the parking lot until the black box arrived.
He didn't pay attention to the new computer. All he remembered was it came in a box marked Bosch. It was actually marked "Remanufactured American Bosch." The computer he turned in for a core performed no better than the one he replaced. It took Chuck a week of lost time after work to figure it out. This computer was also bad. He ordered another and was given a stern lecture by the manager, once again about fishing the job in a timely fashion. The pressure was on.
The next computer was examined more carefully. It was clearly remanufactured and he mistrusted it as soon as he opened the box. The mistrusts turned to hate when the car still ran poorly. The V-8 engine loped and the air-fuel mixture was all over the place. Once again, he stood there scratching his beard in angry contemplation. That was when another mechanic walked by and muttered something that would result in the "Final Fix."
This shop foreman was a very serious fellow. He only took orders from the manager and owner, and interacted with the other mechanics only when absolutely necessary. It was always him telling them how to do something right after it had already been done wrong. He was only to be bothered when the situation was out of control. He would step in and make things fight.
Now one of the mechanics from the ranks was telling him something. It never happened. No one even tried to talk to Chuck. He already knew it all. He only talked with them when they needed his help. Now one of them was saying something to him. "Why is he bothering me?" Chuck thought. "Can't he see that I'm busy... that I'm in trouble... over my head in this mess..."
The mechanic talking to him was the newest one on the floor. He had been hired less than a year ago. Most of the guys had a decade under their belt. 'What is this newcomer trying to do, anyway?" Chuck thought. 'Win some brownie points for being a good sport and trying to help? He can't possibly know what to do in this case... how to find the problem."
The new mechanic had been quietly watching from his bay all along. He saw Chuck put every part in the car and saw the car come back again and again. He watched at the manager and owner pounced on Chuck again and again for not solving the problem. He watched him stand there in this very same stance, scratching his beard over this car, many, many times before.
The new mechanic couldn’t take it any more and had to lend some help. He may have been the newest hired wrench, but he was far from the dumbest. He had learned many tricks of the trade while working for a dealer in Florida and wanted to share one of the best tricks he knew. He said, “Get the other one from the lot and swap the brain. That will prove you are right about it.”
Chuck couldn’t believe his ears. “This is impossible. How could he know?” He thought to himself while peering through his coke-bottle glasses at the new kid on the block. “What? You mean pull a switch?” Chuck muttered softly. “Yes, the new guy whispered and quietly walked away to the parts counter where he picked up a box of parts, then quietly walked back to his work station, never turning his eyes in Chuck’s direction the whole time. Chuck just kept peering at him.
When he thought no one was watching, Chuck went and got the keys for the other 450SEL on the lot and as quietly as possible pulled it onto his spare service bay. It was about lunch time and he knew the meant would retreat to the lunch room shortly. He would be alone in the shop. He could do a brain transplant without anyone knowing what was going on.
The men had hardly made it upstairs to the lunch room before he had the “known functional” brain out of the other 450SEL. Chuck didn’t even bother to bolt it in its mounting pad, but attached the umbilical harness and quietly closed the hood to take it for a test ride. As soon as he stepped on the gas, he knew the problem was gone.
Chuck had no way of seeing the trees for the forest. He had been under so much pressure from above that he didn’t see how to fix the car. It was the easiest and oldest trick of the trade. Get another car that worked just fine and start swapping parts until the problem goes away. He was thankful for the insight and in a show of friendliness that was completely unlike him he walked up to the lunch room and thanked the new mechanic in front of all the other men.
