Allen McCormick
About Allen McCormick
I have worked with General Motors vehicles since 2007, and everything published on this site comes out of that experience rather than out of a content brief.
Where the experience comes from
2007 – 2019, Chevrolet sales, Saskatoon, Saskatchewan. Over a decade helping customers match GM vehicles to what they actually needed, from Silverados to family SUVs. That is where I learned how GM builds things, how trims and packages differ, and how much of a buying decision comes down to details nobody mentions in a brochure.
2019, Chevrolet sales, Las Vegas, Nevada. Same work, new market.
2019, Service Advisor, Findlay North Volkswagen. Moving from sales to service changed how I think about vehicles. Sales is about what a car can do. Service is about what goes wrong, why, and what it costs to put right — and about explaining that honestly to someone who did not expect the bill.
2021 – present, Service Advisor, Fairway Chevrolet, Las Vegas. Back with GM vehicles full time, on the service side, working through real repair orders on the vehicles this site writes about.
Why that matters for what you read here
A service advisor sits between the technician and the customer. You see which complaints come in repeatedly, which repairs actually fix them, which parts fail again six months later, and how often someone has already paid for a part that was never the problem.
That perspective shapes the diagnostic guides on this site. When a page says to check a ground connection before replacing a catalytic converter, or to test crankcase pressure before condemning a turbocharger, it is because the alternative is a bill somebody did not need to pay.
How I write these guides
Technical articles here are built from GM's own documentation — technical service bulletins, preliminary information documents and special coverage notices — read directly rather than summarised from a database. Bulletin numbers are checked against the actual document to confirm the document covers the code and the vehicle being discussed.
Where a claim cannot be supported, it gets removed and the removal is stated on the page rather than edited away quietly. The full standard is set out in the editorial policy.
Work that shows the standard
Rather than asking you to take that on trust, here are pages where the method is visible on the page itself.
Primary documents read in full, not summarised:
- 6.2L L87 maintenance and the 25V-274 recall — built from the NHTSA Part 573 report and the GM dealer bulletin, including the production window and the change in oil specification for engines that pass inspection.
- AFM and DFM lifter failure — what the symptoms actually indicate, and what a repair genuinely involves.
- Checking GM recalls by VIN — including why Special Coverage programmes do not appear in a NHTSA lookup, which is how owners end up paying for repairs GM would have covered.
Pages that carry their own corrections:
- The Complete GM & Chevrolet Owner's Guide — carries a visible list of what earlier versions got wrong, including a Corvette model description and a cargo-space figure that could not be supported.
- The maintenance schedule guide — previously listed timing belt inspection as a mileage milestone. Modern GM engines use chains. The correction is stated on the page.
- Resetting the oil life monitor — previously suggested disconnecting the battery as a last resort. That does not reset the monitor and causes other problems, so it was removed and the reason given.
Pages that argue against a sale:
- GM lemon law — an earlier version suggested fixing a problem yourself was usually cheaper than pursuing a claim. We sell parts, which gives us an interest in that answer, so it was removed. Consultations are frequently free and many state statutes shift attorney fees to the manufacturer.
That last category matters most to me. A parts store writing technical guidance has an obvious conflict of interest, and the only useful response is to name it on the page when it applies.
What this site is and is not
GM Service Guy is an online parts and accessories store. It does not perform repairs, book service appointments, or operate a physical service location. Any business offering vehicle servicing under a similar name is not connected to this one.
Fitment questions come to me directly. If you are unsure whether a part suits your vehicle, send your VIN and what you are trying to solve to allen@gmserviceguy.shop and you will get an answer from someone who works on these vehicles for a living.