08/27/2026
2015 Kia Sedona — Diagnosing Beyond the Obvious
This 2015 Kia Sedona came into our shop with a significant oil leak. The initial diagnosis from other shops was a rear main seal.
These Kia engines are known for oil leaks originating from the oil filter housing and pressure sensor, which can leak into the valley beneath the intake. At first, everything pointed in that direction, so we replaced those components and reassembled the engine.
Unfortunately, the leak was still there.
I had a strong suspicion that we were dealing with a head gasket leak. With this engine using an aluminum block and aluminum heads, I decided to pressure-test the crankcase. I installed a fitting into the oil filter housing cap and pressurized the crankcase.
Sure enough—the source of the leak became very clear. Oil was bubbling out through the head gasket.
We ordered the necessary parts from Kia and began disassembly. During the teardown, we noticed that several of the head bolts were already loose.
When it came time to torque the head back to manufacturer specifications, we discovered another problem: several of the head bolt threads had pulled out of the aluminum block and would not hold the required torque.
The recommended repair was to drill and install Time-Serts to restore the damaged threads. We performed the repair, but unfortunately, some of the threads still would not hold to the manufacturer’s specifications.
At that point, rather than continuing to put money into an engine that was becoming increasingly difficult to repair properly, we decided to pay it forward.
We located a low-kilometre used engine and replaced the engine at our cost.
The Sedona is now back on the road and running properly. 💪🔧
This is a great example of why proper diagnosis matters. Sometimes the obvious answer isn’t the correct one, and finding the real problem takes experience, testing, and a willingness to dig deeper.
Another challenging diagnosis solved!
🔧🚗
