60K-Mile DIY Intake Valve Cleaning for Genesis GV70 & GV80 3.5T Engines

If you own a Genesis GV70 or GV80 with the 3.5T engine, keeping your intake valves clean is one of the best ways to maintain performance and reliability long-term. Like most modern GDI (Gasoline Direct Injection) engines, the Genesis 3.5T can develop carbon buildup on the intake valves over time — especially around the 60,000-mile mark. The good news? Cleaning your intake valves is an easy, at-home maintenance task that can restore lost power and efficiency in under an hour.

Why Intake Valve Cleaning Is Critical for GDI Engines

Unlike traditional port-injection engines, which spray fuel before the intake valves (washing them clean with each combustion cycle), GDI systems inject fuel directly into the combustion chamber. This design improves efficiency and performance, but it also leaves the back of the intake valves unwashed by fuel.

Over time, oil vapors from the PCV system and carbon particles from combustion collect and harden on the intake valves. In the Genesis 3.5T engine, this buildup can:

• Restrict airflow into the cylinders
• Cause rough idle, hesitation, or misfires
• Reduce horsepower and throttle response
• Decrease fuel economy

That’s why performing an intake valve cleaning every 60K miles is so important — especially on the twin-turbo Genesis 3.5T where airflow and boost response are everything.

 

The DIY Genesis 3.5T Intake Valve Cleaning Process

This process applies to both the GV70 3.5T and GV80 3.5T, and is similar for other Genesis, Hyundai, and Kia GDI engines.

You’ll need:

• 1 can of CRC GDI IVD Intake Valve & Turbo Cleaner (available on Amazon HERE)
• Basic tools to remove your engine cover
• About an hour of time

 

Step 1: Warm Up the Engine

Start your Genesis and let it reach normal operating temperature. This ensures the cleaner works effectively once introduced.

Step 2: Locate the PCV Vacuum Line

Remove the engine cover to expose the intake manifold. On the Genesis 3.5T, the large PCV vacuum line you’ll need is located at the front of the intake manifold (circled in the picture here). This is the access point for introducing the cleaner.

Step 3: Apply the CRC Cleaner

Follow the instructions on the can carefully. With the engine idling, remove the vacuum line and begin spraying the CRC GDI IVD Intake Valve & Turbo Cleaner into the manifold in short bursts, making sure the engine does not stall or rev above 3,500 RPM.

The cleaner will flow through the intake runners and coat the valves, breaking down baked-on carbon deposits.

Step 4: Let the Cleaner Soak

Once the can is empty, shut off the engine and allow it to soak for 45 minutes to an hour. This gives the cleaner time to loosen stubborn carbon buildup.

Step 5: Burn Off the Residue

Restart the engine and take your GV70 or GV80 for a spirited 10-15 minute drive to blow out any loosened deposits. A bit of smoke from the exhaust at first is completely normal — it’s just the cleaner doing its job.

Step 6 (Optional, but Highly Recommended): Change Your Oil

While an oil change isn’t strictly required after performing this procedure, it’s strongly recommended. During the cleaning process, a small amount of the valve cleaner may enter the crankcase, potentially diluting your engine oil and introducing cleaning agents not intended for long-term circulation. Changing your oil afterward ensures your engine stays properly lubricated and free of contaminants, helping maintain peak performance and longevity.

Optional: Scan and Clear CELs (If Any)

Sometimes, this process may trigger a temporary Check Engine Light (CEL) — nothing to worry about. It’s always good to keep a Bluetooth OBD2 scanner handy like the Veepeak OBDCheck BLE for quick code reading and clearing. Find it HERE

For what it’s worth, no CELs appeared during our test on the Genesis 3.5T.

 

Dealer vs. DIY — Save the $100+

Dealerships and repair shops offer intake valve cleaning services for $100 or more, but this is one of the easiest maintenance procedures you can do yourself.

Performing your own GDI intake valve cleaning will:

✅ Restore throttle response and smooth idle

✅ Improve MPG and overall fuel efficiency

✅ Reduce future carbon buildup

✅ Maintain peak twin-turbo performance

Final Notes

Always perform this procedure responsibly and at your own risk. Follow CRC’s product instructions closely, and make sure the vehicle is in a well-ventilated area.

Even though this guide focuses on the Genesis GV70 and GV80 3.5T, the same principles apply to many other GDI engines found in Genesis, Hyundai, Kia, and other manufacturers’ vehicles.

 

Boosted Mentality Motorsports — Premium Performance for Premium Vehicles

Performance starts with proper maintenance.