Auto Service World
Feature   April 1, 2001   by Rick Cogbill a.k.a. Slim Shambles

A Multi-tude of Frustrations!

When Murray plunked a file full of papers down on my counter, I thought he was showing me a manuscript for his latest book. "Whatcha got there, Murray? Romance or Sci-fi?" "Neither," said our resident...

When Murray plunked a file full of papers down on my counter, I thought he was showing me a manuscript for his latest book. “Whatcha got there, Murray? Romance or Sci-fi?” “Neither,” said our resident author. “It started off as a mystery, but it’s becoming a horror story!” I opened the file and discovered a stack of repair invoices for his 1986 Nissan Multi. Thankfully, none of them had come from me. “I’ve been taking it back to the dealer, in fact to the same mechanic, ever since I bought it new,” he explained. “But it’s been acting strange lately, and they can’t find the problem.” He pulled out his pipe and fumbled for his tobacco pouch. Lighting it up, he took a deep draught. “Feel like giving it a go?”

I looked out into the shop where Tooner was working on his own truck. Being February, things had been slow lately, so we had nothing to lose. “Sure, why not. Leave your file with us so we can see what’s been done.” Later that morning, as we mourned the demise of an entire box of Tim Horton’s donuts, Basil arrived back from a service call. “Looks a bit picked over,” he said gloomily, peering at the crumbs. “Yeah,” agreed Tooner with a loud belch. “Kind of like this Multi I’m working on. Judging from the records, every mechanic at the dealer has worked on it, including the parts driver.”

“What are the symptoms?,” sighed Basil, in search of a cup of coffee to drown his sorrows. It isn’t often that we beat him to the donuts. “Runs fine cold,” replied Tooner, “but it begins to roll at idle when warm, and on the highway it will buck quite badly.”

“Is it time for a tune up?” asked Beanie.

Tooner snorted. “They’ve done two since August! And in only 20,000 kilometres.”

“It could be a module problem, cutting out when warm,” I suggested.

Tooner sighed. “Could be, but at over $280 a pop, I wouldn’t bet my life on it.”

But nothing better came to light, so after digging around in the local wrecking yard, we tried a used distributor, which is where the ignition module is located. But as with all wild guesses, it didn’t help.

Tooner dragged over the MotorVac machine. “Maybe we can clean a little carbon off the valves with an injector cleaning,” he said, hooking up the hoses. To our surprise, the little car perked right up immediately. Even the engine vacuum increased.

But when he unhooked the machine, the rolling idle was back.

I looked into the records. “It seems that all this started last spring when someone changed the intake manifold gaskets. Could there be a vacuum leak?”

Tooner pulled a vacuum hose off the intake port, the same one he had used during the MotorVac, and plugged in his gauge again. Immediately, the rolling stopped, and the Multi purred like a kitten. “What the…!” exclaimed Tooner. Tracing the vacuum hose, he discovered that it went over to the charcoal canister. Whenever he hooked it back up to the engine, the rolling idle returned. “Something’s wrong here,” he muttered. “Beanie, find me the diagram for these emission hoses.”

A lengthy search through the repair manuals revealed little, as the Multi is a Canadian-only vehicle, and not mentioned in the American-based guides. A Nissan Sentra is about as close as you can get. But by trial and error, we discovered that at some point, probably during the intake gasket job, somebody had reversed hoses on the charcoal canister, creating a vacuum leak to the intake manifold. Once we switched them around, the little car ran like a dream.

When Murray came by later, I explained what we had found. “You can close the chapter on this one, Murray. The mystery is solved.” His whiskered face was lost in a cloud of pipe smoke as he pondered that one. “So when they replaced my intake gaskets last spring, they actually created another problem?” “Looks like it,” I agreed. “Say, you should write a story about this!” “Bah,” he said with a dismissive wave of his hand. “Who would ever read it?”

About The Writer

Rick Cogbill is a freelance writer living in the Okanagan valley of Southern British Columbia. A licensed technician with over 25 years in the automotive repair industry, including ten years as a shop owner, Cogbill creates his comic scenarios with Slim, Basil, Tooner, and The Bean out of actual case histories. “What you have just read is true,” drawls Slim Shambles. “Only the names have been changed to protect my hide!”

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