31,000 Miles In, My 2021 Toyota Tundra Apparently Has "Sludge Build-Up" and Offered To Flush It For Another $50, But I Have Kept Up With The Oil Changes Every 5K

Today I was surfing the Toyota Tundra Nation group on Facebook and read a very interesting post by Aaron Polakiewicz, who writes the following:

“I have a 2021 Toyota Tundra with 31,000 miles. I've had the truck since new and keep up with oil changes every 5k. This oil change chain I just left told me I had sludge built up and offered to flush it for another $50. How likely is this to be true? I never had build-up issues. Toyota says 10K is fine with full synthetic but I don't go with that. The tech showed me oil on the dip stick not actual drained oil. My gut was telling me that he was trying to bs me and possibly put something else on the stick,” Aaron writes.

Aaron’s story is an example of why it pays to be informed and skeptical when visiting quick-lube shops. His maintenance history doesn’t align with the claim of sludge buildup, and many experienced Tundra owners agree that this was likely just a sales pitch. While engine sludge is a real issue for neglected engines, a properly maintained Tundra should not have this problem at just 31,000 miles.

Why Engine Sludge Shouldn’t Be an Issue at 31,000 Miles

Many group members chimed in, questioning the legitimacy of the shop’s claim. Steve Doucharm pointed out, “Unless you're using coal tar in your engine it'd be virtually impossible to get sludge with those oil change intervals.” This sentiment was echoed by Justin Prescott, who quipped, “They really wanna charge 50 bucks to pour 2 quarts extra.”

Other members had more cautious takes. Devin Fitzgerald noted that if cheap-quality oil was used, sludge could develop, though he found it unlikely at such low mileage. His advice? “Stop taking it to them and either DIY or find a legit shop.”

Earl Copeland backed this up with his own experience: “I have 267,000 with synthetic oils, oil done every 5-7K average, all good, no flushes. They are probably trying to upsell you.”

The Dangers of Quick-Lube Shops and Questionable Upsells

Many truck owners remain wary of quick-lube chains, and for good reason. Tim Bradford, a top contributor in the group, strongly advised, “Do yourself and your truck a favor and NEVER take it to an oil change chain. You'll sleep better at night knowing those guys aren’t on your floor mats.”

Robert Collins also weighed in, sharing a similar experience his son had at a dealership: “Those places will tell all kinds of lies to sucker people into spending more money. My son had his Mazda CX-5 at the dealer for a minor warranty repair. A guy from the shop came in, showed him a small vial of very black oil, and asked if he wanted them to change his oil ‘because it was very old and dirty.’ He told the guy he didn’t know what he was talking about because he had just changed his oil the previous day.”

Stories like these highlight why being an informed vehicle owner is essential. Scams and unnecessary upsells are far too common in the industry, and trusting the wrong shop can cost you hundreds, if not thousands, of dollars over time.

Can You Trust Your Car’s Oil Life Monitor?

One of the biggest concerns with modern vehicle maintenance is the reliance on automated systems to determine when an oil change is needed. Many car owners trust their oil life monitor feature without question, but how reliable is it really? If you want to understand whether you can trust your car’s oil life monitor feature and whether it might be leading you astray, check out this in-depth analysis on oil life monitors.

Beware of Car Oil Change Maintenance Disasters

Moreover, quick-lube shops are notorious for attempting to upsell customers with unnecessary services, and sometimes these extra services can do more harm than good. Some owners have even experienced catastrophic failures due to poor-quality oil changes performed by undertrained technicians. You don’t want to end up with a car oil change maintenance disaster, so before you let a shop talk you into extra services, it’s worth reading this guide on avoiding oil change mishaps.

Final Thoughts: Trust Your Gut and Find a Reputable Shop

For Toyota Tundra owners in particular, keeping up with oil changes and using high-quality oil is essential for longevity. However, knowing where to take your truck for service is just as important. Whether you prefer to do it yourself or take it to a trusted mechanic, avoiding shady quick-lube chains could save you a lot of unnecessary stress and expenses in the long run.

The takeaway? Stick to reputable service centers, ask for evidence before agreeing to extra services, and most importantly, trust your gut. If something sounds fishy, it probably is.

Armen Hareyan is the founder and the Editor in Chief of Torque News. He founded TorqueNews.com in 2010, which since then has been publishing expert news and analysis about the automotive industry. He can be reached at Torque News Twitter, Facebook, Linkedin, and Youtube. He has more than a decade of expertise in the automotive industry with a special interest in Tesla and electric vehicles.