Head Bolt Stripping in Kia and Hyundai Engines: How Common Is It and How to Fix It

A customer recently emailed us with a great question: “What percent of Kia vehicles would you say have the head bolt stripped?” It’s a common concern for owners of Kia and Hyundai vehicles with 3.3L, 3.5L, and 3.8L engines and it’s no surprise why. Stripped head bolt threads in aluminum engines are a known headache, especially for models using M11x1.5 head bolts (like those compatible with Fel-Pro ES72366 head bolt). Let me provide a little more info on the issue and I'll share the best fix for it—spoiler alert: our Time Sert kits have you covered. How Common Are Stripped Head Bolts in Kia and Hyundai Engines? Unfortunately, there’s no official data from Kia or Hyundai that gives an exact percentage of vehicles affected by stripped head bolt threads. Without large-scale studies or manufacturer reports, it’s tough to nail down a precise number. That said, if you’ve spent any time on automotive forums or talking to mechanics, you’ve likely heard about this issue cropping up in certain models, here's a partial list including:

Hyundai Azera (3.3L 2007–2017, 3.8L 2006–2011)
Hyundai Entourage (3.8L 2007–2010)
Hyundai Genesis (2009–2016)
Hyundai Santa Fe (3.3L 2006–2019, 3.5L 2010–2012)
Hyundai Sonata (3.3L 2006–2010)
Hyundai Veracruz (3.8L 2007–2012, 2008–2011)
Kia Sorento (3.3L, 3.5L, 3.8L, various years)

The problem often shows up at higher mileage—think 100,000 to 150,000 miles—when the steel head bolts strip the softer aluminum threads in the engine block. This can lead to head gasket failures, coolant leaks, or worse. It's important to realize that a simple over condition from a coolant leak froma hose or radiator could stress the threads enough to cause failure also. While not every vehicle is affected, the issue is common enough in these models to keep mechanics and DIYers busy. The material mismatch (steel bolts in aluminum blocks) is the main culprit, and factors like improper torquing or thermal stress can make it worse. The Best Fix: Time Sert Thread Repair Kits. If you’re dealing with stripped head bolt threads, don’t panic—replacing the entire engine or block isn’t your only option! At Wise Auto Tools, we recommend the Time Sert 2200 kit for first-time repairs on Kia and Hyundai engines with M11x1.5 head bolts. This kit is designed to restore the threads with precision, giving you a stronger, more reliable fix than the original setup. The Time Sert 2200 installs a solid steel insert that’s torque-tested to handle the demands of your engine and thermal cycling. For cases where a previous repair has failed (like a poorly installed insert or a Helicoil style repair), we’ve got you covered with the Time Sert 2200BS oversize repair kit. This kit is perfect for those “uh-oh” moments when you need a larger insert to get the job done right. Both kits are easy to use with the right tools and following simple instructions, saving you time and money compared to pricy shop repairs or engine replacements. Why Choose Time Sert?

Durability: The steel inserts are tougher than the original aluminum threads, reducing the risk of future failures.
Precision: Time Sert kits are engineered for a perfect fit, especially for M11x1.5 head bolts used in these Kia and Hyundai engines.
Versatility: Whether it’s a first-time fix (2200) or a rescue for a botched repair (2200BS), these kits are the go-to solution.
Cost-Effective: Skip the dealership markup and fix it yourself with confidence.
Installing a replacement block or engine means aluminum threads are still at risk of failing.

Tips to Avoid Stripped Threads

Time Sert thread repairs are considered permanent and should last the lifetime of the engine. Reduce the risk of thread failure with these tips:

Proper Torquing: Always use a torque wrench and follow the manufacturer’s specs when installing head bolts. Replace TTY bolts when doing the job.
Consider repairing all holes while the head is off, because the weakest point is likely to fail next.
Regular Maintenance: Keep an eye on your temperature gauge and cooling system to avoid overheating, which can stress the bolts.
Use Quality Parts: Stick with OEM or high-quality aftermarket bolts (like Fel-Pro ES72366) to ensure a secure fit, that meets the manufacturer's specs.

Got Questions? We’re Here to Help! Stripped head bolts are a pain, but they don’t have to be a dealbreaker. Whether you’re working on a Hyundai Santa Fe, Kia Sorento, or any other model with a 3.3L, 3.5L, or 3.8L engine, our Time Sert 2200 and 2200BS kits are the smart choice for reliable repairs. If you’re wondering about specific models, tools, or repair tips, drop us a line at Wise Auto Tools—we’d love to help you get back on the road. Shop now for the Time Sert 2200 and the Time Sert, Big Sert 2200BS kits at and tackle those stripped threads with confidence!

9th Jul 2025 DennisB