Home How-to Articles Road Ready Episode 7:

Road Ready Episode 7:

by Moses Ludel

Being a ‘Parts Replacer’ Wastes Time
and Spends Money Needlessly

Forums and how-to YouTube videos can be helpful information. At times, however, consumers wind up with a long list of parts that might possibly contribute to a symptom. Episode 7 of Road Ready shares why the right diagnostic tools and troubleshooting methods can save considerable expense and time when chasing down a symptom’s cause.

Becoming a journey level mechanic in the late ‘sixties and early ‘seventies, I learned the definition of “parts replacer”. This derogatory term haunts ‘DIY’ and professional technicians to this day. The seasoned professional knows that installing “test parts” wastes time and is always more costly.

When parts that might solve a problem become your shopping list for the local parts house, that’s a crapshoot and not diagnostics. Some or all of the parts on your list may still be functional; replacing them may not cure the symptom. In addition to the needless parts expense, labor time gets wasted when removing and replacing good parts.

Our Ram Cummins delivers 12-14 mpg with this trailer and cargo in tow. The “new” vehicle in our fleet is a pristine 2003 Jetta TDI one-owner time capsule in exceptional condition at 106K miles. The turbo-diesel Jetta offsets the XJ Cherokee’s 12-16 mpg by delivering an impressive EPA 34 City/45 Highway mpg rating with the automatic transmission. This vehicle earns its own set of factory-level service manuals from Bentley Publishers.
Each vehicle we own has an FSM on the shelf. Equipped with this 2008-page two volume service manual set from Bentley Publishers, I will perform any service and repair work required on the Jetta TDI GL Wagon to “factory” standards. This includes drilling down and pinpointing the cause of trouble symptoms. That’s professional level diagnostics…The 1.9L ALH diesel engine has a loyal following. This reliable, fuel miserly powerplant has even served as an emissions legal transplant into lighter Jeep 4x4s. This book set is valuable to anyone servicing and repairing a VW Jetta A4 platform, Golf or GTI of this vintage. Savvy owners who sublet their work to a shop can benefit from knowing the procedures outlined in this two-volume service manual set.

From a consumer standpoint, if you sublet your repair work to a shop, this can sometimes get worse. A troubleshooting symptom may have several possible causes. To save time under the flat rate system, a number of parts may get replaced to cover all possibilities. The symptom disappears, but which replacement part was the actual cause of the problem? How many parts were needlessly replaced? The repair bill is for all of the parts plus their installation labor.

Our shop relies on Autel for pinpoint diagnostic tools that save time and get to the source of a problem. Scan tools like the Autel MS906TS (shown) are cost-effective for both professional technicians and serious ‘DIY’ users wanting accurate analysis of problems. A valuable option is our Autel MP408 oscilloscope for universal troubleshooting of any device that can be read as voltage/amperage over a time interval…This is the contemporary way to avoid being a “parts replacer”.

Modern scan tools, an automotive oscilloscope and the tests outlined in a factory workshop manual can help eliminate needless parts replacing. There is less likelihood of replacing fully functional parts when you test parts before removing them. A scan tool can often test parts in place, streaming live, real time data from the vehicle’s PCM, ECU or ECM. Some less expensive scan tools and cell phone apps can also stream basic live data from the onboard computer.

I highly recommend the Autel MS906TS as a cost-effective, professional grade diagnostics tool. You own the tool and its currently loaded software . While annual subscriptions are available for shops that want the latest coverage, the software initially provided by Autel does not “disappear” after the first year’s subscription. A costly industry practice is cloud service fees with cloud tech centers and databases. These come with very expensive, ongoing subscriptions. Autel offers the small to medium size independent shop or serious DIY consumer an affordable, professional alternative. The Autel tools are an excellent value and well engineered.

This 1998 Mopar FSM gets a workout on our XJ Cherokee service and also for 4WD Mechanix ‘Tech and Travel’ Forums questions. I actually prefer the later CD versions that enable rapid navigation. You can print out service procedures and take the copy into the shop environment, avoiding the risk of smudging up a print manual! My library is five bookcases packed with FSMs, trade manuals and resource data dating from the 1910s to present. For more than five decades, I have added an FSM or trade manual to cover each automobile, truck or motorcycle that has passed through my professional and personal service bays. These materials have been crucial references for tech columns, magazine and newspaper articles and my seven Bentley books.

At the 4WD Mechanix ‘Tech and Travel’ Forums, there are many topics and posts by ‘DIY’ consumers who went down the “parts replacer” path without curing the problem. Make sure you know which part is defective before heading to the parts house. In-depth troubleshooting saves time and considerable expense. Be a diagnostician and not just a parts replacer. Forthcoming episodes of Road Ready will devote considerable time to diagnostics and troubleshooting.

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