Questioning "dealer service recommendations"
#1
5th Gear
Thread Starter
Questioning "dealer service recommendations"
2017 C7 Grand Sport Owner, and fairly new member here, and this is my first post. Thank you for allowing me to join the group. After my last oil change at my Chevy dealership, they gave me a list of things I "need to do soon" for my Corvette. These things include (1) Fuel injection and throttle body cleaning, (2) Brake fluid exchange, (3) Rear differential fluid exchange, (3) Cooling system exchange, and (4) cabin air filter replacement. All this poses some questions.... (A) Do I really need to do these things in a car that has only 34,000 miles? (B) If I do need to do these things NOW, can I have them done by my local mechanic at one-half the cost a dealer will charge? (C) If I skip any of these things OR have them done by my local mechanic, will that void my (authentic GM) extended warranty? Other than a cabin air filer replacement (which I can easily do myself), I have never done any of these things on any car I've owned until they reached close to 100k miles. And I've owned 35 cars in my life. Thanks very much for your help with this. I will greatly appreciate any advice you can give me.
#2
Drifting
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Well, according to the owners manual, both brake fluid and rear axle fluid aren’t due until 45k miles. Engine coolant flush is 150k. I’d say yes to the cabin air filter replacement. That first replacement is 22,500. …and a hard NO to the fuel system cleaning if she’s performing well. I just added a full can of Sea Foam to a full tank of gas recently. That’s the extent of my injector cleaning.
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Tcape17 (03-23-2024)
#3
Instructor
I'm curious about this too. I bought a '17 base Stingray with 7800 miles in December. As "like new" as one would hope. The PO had the seats covered so it looks like they've never been sat on, and he covered the car at his work every time he drove it; more **** then me...LOL. Runs and drives flawlessly, A8 shifts perfectly. I did buy a Range device and new set of Michelin Pilot Sport P4's (non runflats). I've read all the horror stories about triple flushing the A8, but not planning to do it unless/until I have some issue. As far as I know, the only maintenance done by the PO was a couple of oil changes. The Owners Manual isn't really very helpful for low mileage cars. I don't want to do unnecessary stuff, but do want to keep the car in top shape for me, and (if I ever sell it) for the next owner. I will only drive it occasionally, couple thousand miles a year max.
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Tcape17 (03-23-2024)
#5
Drifting
Many fluids are not just dependent on mileage. Additive packages in oils starts breaking down as soon as they are exposed to combustion. So of course engine oil, even in a car that maybe only got driven 50 miles in a year, should still be changed at least once a year.
Brake fluid absorbs moisture out of the air (it does make its way in) and lowers the boiling point. Typical DOT3 offers a good balance of longevity. But higher performance guild like DOT4 which is the factory fill on later C7s and many other high performance vehicles, absorbs moisture at a higher rate. So it goes “bad” faster. DOT3 should be flushed out every 3-4 years and DOT4 should be done every 2-3 years. Even more frequently if you are tracking the car.
Coolant has an anti corrosion additive package which breaks down over time. The current “Dex Cool” that GM uses should be flushed after 5 years even on a low mile car.
Air and cabin filters…I feel the factory interval is a general guide, but I’ve seen plenty look awful friggin bad if you actually wait that long to replace them. Operating the vehicle in higher than normal pollutant areas will load those filters up faster and restrict airflow. A restricted air filter can sap some power from the engine. Cabin filters are interesting. I’ve seen some that don’t have many miles on them, and something weird got sucked in and started forming mildew on the filter. These things aren’t HEPA filters, so some things do get through. Just for the sake of health, I’d replace those things probably every year.
Brake fluid absorbs moisture out of the air (it does make its way in) and lowers the boiling point. Typical DOT3 offers a good balance of longevity. But higher performance guild like DOT4 which is the factory fill on later C7s and many other high performance vehicles, absorbs moisture at a higher rate. So it goes “bad” faster. DOT3 should be flushed out every 3-4 years and DOT4 should be done every 2-3 years. Even more frequently if you are tracking the car.
Coolant has an anti corrosion additive package which breaks down over time. The current “Dex Cool” that GM uses should be flushed after 5 years even on a low mile car.
Air and cabin filters…I feel the factory interval is a general guide, but I’ve seen plenty look awful friggin bad if you actually wait that long to replace them. Operating the vehicle in higher than normal pollutant areas will load those filters up faster and restrict airflow. A restricted air filter can sap some power from the engine. Cabin filters are interesting. I’ve seen some that don’t have many miles on them, and something weird got sucked in and started forming mildew on the filter. These things aren’t HEPA filters, so some things do get through. Just for the sake of health, I’d replace those things probably every year.
#7
Drifting
A friend got a list of items performed after having an oil change at a local GM dealership. One of the items checked off was that they had checked the air pressure of the spare tire. ;-)
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Tcape17 (03-23-2024)
#8
5th Gear
Thread Starter
Thanks so much, folks for all your great information. I really appreciate it. Looks like I can wait until I hit the 45k-mile mark to do the items on the list I posted. Well, except change the cabin air filter and engine air filter. Both of which I can do myself. And thanks to "CorvetteMike2024" and others who posted the require maintenance schedule. That's really helpful. Nice to be part of a group that helps so quickly and with such good info.
#9
Pro
I understand your reasoning on waiting until 45K miles, but I believe you are making a mistake. Notice the service schedule is based on distance AND time in some cases. Your 2017 is approx. 8 years old and if the fluids have never been changed you are taking a chance on major repairs. Replacing fluids is cheap insurance vs. major rebuilds. If you plan to keep this Vette, I would recommend that you have your mechanic, if you trust him, change all the fluids over the next couple of months so the cost is spread out. Good luck.
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Guard Dad (03-23-2024)
#12
5th Gear
Thread Starter
The other part of my question is....... if I do all this work myself, or if I have my local mechanic do it, does it jeopardize--or even invalidate-- my (authentic GM) extended warranty??
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Tcape17 (03-24-2024)
#14
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Simply go by the Owners Manual or the linked site above. The dealer will "sell" you anything you're willing to pay for.
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Tcape17 (03-24-2024)
#15
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For your extended warranty, I am sure you have to follow the recommended maintenance as outlined in your owners manual. As such, of that list, I am sure your coolant needs to be changed if it has never been changed (the time requirement of five years rather than the mileage). Wouldn't be a bad idea to change the brake fluid too. You can check the status of your cabin air filter very easily so you may or may not need to buy a new one. And no, you do not need to have the work done at a dealership - just make sure the shop doing it knows what they are doing.
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Tcape17 (03-24-2024)
#16
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I would do the cabin filter/brake fluid/& the coolant recommendations considering that your car is 7 years old
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Tcape17 (03-24-2024)
#17
Burning Brakes
It's not unrealistic to have the services performed while not exceeded by mileage, but exceeded by time.
My 2014 has 32K miles and I've considered performing many of these maintenance items specifically for that reason. I'm sure in the case of my 2014 many of these fluids are factory installed and have never been changed. It's certainly time to do so; perhaps, not by mileage but by time.
I say no to the injector service. I use Top Tier Fuel from Costco. But, Top Tier labeled Fuel can be found at many gas stations across the US, not specifically from Costco. Regardless, I have never suffered an injector of fuel distribution problem with any of my vehicles. They run and perform well. In the case of the Denali, 250+K miles.
My 2014 has 32K miles and I've considered performing many of these maintenance items specifically for that reason. I'm sure in the case of my 2014 many of these fluids are factory installed and have never been changed. It's certainly time to do so; perhaps, not by mileage but by time.
I say no to the injector service. I use Top Tier Fuel from Costco. But, Top Tier labeled Fuel can be found at many gas stations across the US, not specifically from Costco. Regardless, I have never suffered an injector of fuel distribution problem with any of my vehicles. They run and perform well. In the case of the Denali, 250+K miles.
#18
5th Gear
Thread Starter
Thanks to everyone for the great advice on having some of the time-related (not mileage related) maintenance done now, given that my 2017 Grand Sport is seven years old. Nice to know that the good folks here can steer me in the right direction. Greatly appreciated.
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Carvin (03-24-2024)
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Tcape17 (03-27-2024)