I'm a long time GM customer who purchased 3 Suburbans and remain loyal to keeping my repair business local (dealership name provided upon request). We have a long history together in Mount Pleasant, SC (good hint). But the last two maintenance visits I've had sub par experiences. I paid over $6K on brakes last time (in January 2025), mostly because I was over a barrel and didn't have time for alternate solutions. I questioned the need but paid all the same and it left a very bad taste in my mouth.

Recently it started running rough, reduced power and threw a P0305 code. I needed other work done so i scheduled an appointment for Tuesday, Sept 22nd. Not until Thursday did anyone bother looking at the car, but okay, it's a 3rd car and usually sits unused. But why schedule days before anyone plans on looking at it and then only give it a hour before giving up? The customer rep (and only positive part of this story) kept me well informed but all he could pass along amounted to no more than the mechanics shrugging his shoulders. Come Friday, I learned the mechanic has absolutely no clue (my words) what's wrong on a simple misfire code, but I was charged a couple hundred for diagnostics all the same. In fact, expensive valve/cam work and a complete

spark plug replacement ($500..really?) was the next recommended option. I kindly directed the service rep wrap it up, I brought it home and investigated the problem myself.

Five minutes on YouTube I learn the most common problem with misfire is either the spark plug, spark plug wire or ignition coil, or all three. So, swapped sets for no.1 and no.5 and it threw a new code for cylinder number 1. Bingo, this indicates the problem is as suspected. This morning, I bought all three parts from the dealer (at 2-1/2 times the prices quoted on GM's web page - jeez, is there no end? ) and replace the parts in under 30 minutes. No more roughly idle, no more code. The car is fixed.

Here's my thought, either the dealer is unaware of the issues with the maintenance department or they are and willfully passing the unnecessary cost to loyal customers?

word for word, this will be sent up GM's chain of command but in the end, i really hate not trusting our local dealership. it worked well when it was working.

it usually not in my nature but i've had enough with this dealership.

 

Request a refund, and if dealer refuses, dispute the charge with your credit card company, as you paid for a FIX, not for guessing.

The ONE time we tried a GM dealership to fix the intermittent non-closing sunroof on our 2005 Yukon, after changing out the switch and numerous return visits, that dealership actually told me "we have no idea what is wrong". Apparently they had ONE guy experienced with a sunroof, and I had informed them beforehand that I'd pay for a FIX but not for them guessing with my dollars. I got my $250 refunded from the dealership, and once I got the sunroof closed, I took out its fuse so it couldn't open or get stuck open.

 

If you got charged 6k for brake work, I’d seriously rethink what garage you’re going to. Even on the most complex brake job, hoses, calipers, rotors, and pads, I can’t see it being more than 2k maybe 3k if its a long job. That’s just estimating each wheel at under $500 parts and labor.

And if you brought a car in for a misfire and they didn’t at least recommend the basic plugs, wires, and coil change, I’d never go back. That’s mechanic 101, even though swapping parts around to test is still better than just throwing money at it.

I had a similar run-in with a local shop a few years ago. Not a dealer, but a big name in town. I actually used to deliver parts to them 20 years ago when I worked at AutoZone, so I knew them well. And yeah, dealers and shops buy their parts from the same stores you do, then double the price.

Anyway, my mom’s van (a ’99 Ford E150 4.6) had a misfire. I swapped the coils to test, and the issue didn’t follow, so it had to be plugs or wires. It also had an EGR code for carbon buildup. I didn’t have time to fix it myself, so I told her to take it to this shop I trusted. Big mistake.

Their ‘mechanic’ replaced a coil and claimed he cleaned the EGR. Problem still wasn’t fixed. When I checked it myself, I found a spark plug boot not clicked in all the way, snapped it on and misfire gone. The throttle body? Clearly never touched, bolts still dirty, no tool marks.

I confronted them. As I walked in I asked the daughter nicely not letting her know what was going on if I could speak to the mechanic. The mechanic comes in all happy to help, the mechanic swore he tested the coil with some machine, said it was bad. I just let him keep talking as there was a few people in the room. Then I asked about the EGR, he said he had a flexible tool that could snake in the ports and clean them. After he said all that, I told him I had swapped coils already, and the code never moved. So there was no way the coil was bad, He kept insisting it tested bad. Then i asked him about his magic EGR-cleaning tool, if he shoved a brush in without removing it, where did all the metal shavings and carbon go? Back into the engine? He just stared, then walked out.

The daughter (who ran the place after her dad passed) literally turned her chair and ignored me. I didn’t demand money back, just left and spread the word. Within months they were out of business. Probably not just because of what they pulled on my mom, but because they’d been doing it to everyone.