Highlander V6 Leaking Oil? The Cooler Line, VVT-i Hose and Valve Cover Leaks Explained

Oil spots under a Toyota feel wrong, like finding a typo in a dictionary. But the 2GR-FE V6 that powered a lot of Highlanders has some known weak spots, and two of them are rubber hoses carrying pressurized oil. That's the part worth taking seriously.

Leak #1: the VVT-i oil hose

The 2GR-FE feeds oil to its variable valve timing (VVT-i) actuators through a line that has a rubber section. Tomorrow's Technician explains that the rubber can degrade and develop a pinhole, and corrosive PCV gases can make it worse. If it lets go, you can lose oil quickly. Toyota's own memo lists the symptoms as oil leaking, abnormal engine noise and the oil pressure light coming on.

Toyota handled this with Limited Service Campaign 90K. The extension memo covers about 117,500 V6 vehicles, and the Highlander listed is the 2008 model year (alongside 2005-2009 Avalon, 2007-2010 Camry, 2006-2009 RAV4 and 2007-2010 Sienna). Not every VIN qualified. Dealers replaced the hose with an all-metal kit at no charge, but the extension ran only until December 31, 2021. That window has closed.

Leak #2: the external oil cooler lines

On many 3.5 V6 Highlanders, Sienna, Venza and Lexus RX350 models, oil runs from the upper oil pan to an oil cooler through thick reinforced rubber lines. Car Spec, a Toyota and Lexus specialist, says they can fail where the rubber meets the metal fittings, just ahead of the oil filter housing. In rare cases a line fails completely, and the shop warns that can cause catastrophic engine damage.

Toyota and Lexus announced extended coverage in July 2014. Until January 31, 2016, any seep or leak was covered with no mileage limit. After that, failures were covered up to 10 years from first delivery or 150,000 miles, whichever came first. A Highlander first sold in 2014 or earlier is now past 10 years, so for most trucks this one is over too. If yours was delivered late enough to still be inside 10 years, ask a dealer to check the VIN.

Leak #3: valve cover gaskets

This is the boring, normal-aging leak. Rubber valve cover gaskets harden and seep, oil drips onto hot parts, and you smell it. RepairPal notes a leaking valve cover gasket can cause a burning smell and oil on nearby parts, and that leaks can damage belts and hoses. Spark plug tube gaskets are often replaced at the same time.

What it costs

How to find the leak

• Look just ahead of the oil filter. Wet rubber lines there point to the cooler lines.
• Check the side of the engine and undercarriage. Tomorrow's Technician says a leaking VVT-i hose often sprays oil onto one side of the undercarriage.
• Top of the engine wet and smoky? Valve cover gaskets are the usual suspect.
• Front of the engine, near the crank pulley? Could be the timing cover seal. Tomorrow's Technician recommends confirming with oil dye before tearing in, since leaks can travel.
• Clean, then recheck. Degrease the area, drive a few days, and look again. Fresh oil tells the truth.

Easy things to do first

• Check the dipstick every fill-up until you know where the leak is.
• Keep a quart in the back. Cheap insurance.
• Ask the dealer to run your VIN for any open campaign. It takes a minute.

What to ask the shop

• "Which leak is it, and did you confirm it with dye or a clean-and-recheck?"
• "Is the VVT-i line on my engine the all-metal version or does it still have rubber?"
• "Are the oil cooler lines still covered for my delivery date?"
• "If you're doing valve covers, are the spark plug tube seals included?"

Is it worth fixing?

Yes. A valve cover leak is routine maintenance on an aging V6. A seeping pressurized hose is urgent, because the hose costs far less than the engine it protects. More Highlander help lives on the Toyota Highlander page, and for coolant leaks see our Highlander water pump guide. Prices and campaign details checked October 14, 2026.