EFFORTPOST 2015 Kia Sedona Head Bolt Failure Repair Experience and Procedure (56K WARNING)

In November 2023 my sister purchased a 2015 Kia Sedona. The milage at time of purchase was 100,458mi. At 105,227 miles she experienced no heat coming from the HVAC system and dropped the car off with a local shop. The shop, upon noticing severe oil intermix in the coolant, diagnosed a failed head gasket.

I thought this was odd, since she hadn't experienced any overheating, and decided to research what could cause the issue. During this I discovered the problem with soft castings on KIA/Hyundai 3.3L V6 engines causing the head bolts to work their way out, taking the threads with them. The local shop was not equipped to deal with something of that magnitude, so we had the van towed back to her house.

Upon extensive research and contacting several KIA dealerships, I learned there are a few options moving forward.

• Option one is to replace the engine with a new one. The most expensive option. I also understand there is a long waiting list to acquire one.

• Option two would be to install a used engine. The risk of this being unknown maintenance, as well as the fact that the head bolts could similarly go at any moment.

• The final option would be to remedy the issue on the existing engine, which involves drilling out the bad threads and replacing them with steel inserts. While there is always the chance of the inserts failing, the cost of the procedure is much lower than that of a replacement engine and in my own opinion less risky than gambling on a used engine.

I also understand that Kia is aware of the problem. They used the same engine in the 2016-2017 Sorrento and just recently extended the warranty to 15 years / 180k miles to all owners, specifically to address this issue.

My sister is self-employed, and the Kia is her only form of transportation. She also just barely qualified for the loan, and doesn't have much, if any, money to work with. She needs a working car and cannot wait to see if KIA decides to recall the Sedona in the future. Because of this, I have agreed to help her out with the repairs.

We decided that option three, installing inserts, was the best choice given the circumstances. The problem with option three was finding somebody to perform the work. I contacted twelve separate shops in the Lexington area, and none showed interest in performing the work.

After around two weeks of internal debate and assessing my abilities, I decided to travel from Michigan down to Kentucky in order to perform the job myself. It took about a week to get everything ordered and all of my cowtools packed up, and just over seven hours to drive down.

While digging into the engine I discovered signs that a head gasket had already been replaced on this car. There was excessive sealant on the water pump and timing chain guide surfaces. Bearing journals were engraved with their positions, “KIA LEFT HEAD” was written in marker on the left head. I believe the previous owner experienced a bad head gasket and had it replaced without accounting for the bad head bolt threads. It was then traded in and sold on to become our problem.

Here are some more photos from the disassembly:

Also managed to strip the head on one Allen bolt, one that was in too tight of a spot to fit an extractor. Thankfully I brought my tiny welder and was able to tack a 6mm bit to it.

I had to remove the bumper and a bit of the exhaust but finally was able to get the heads off and confirm my suspiscions. Three of the head bolts took the block threads with them. Also some borescope photos of a good hole and a hole that's been stripped. I've been making sure to document this thoroughly in case I have a chance in the future to get some compensation from KIA.

With the heads off I'm able to drill out the old, weak holes, and thread them to accept stainless inserts, which then provide me with some reinforced, freshly threaded holes to grip those head bolts.

And finally here's what a rethreaded hole with an insert looks like:

Then all that was left was to reassemble everything back in the order I took everything apart. Flush the oil and coolant, fill with fresh, and start her up.

If you have a 2015-2017 Kia and are experiencing head gasket issues, I highly recommend doing this procedure. Anyone with a decent set of cowtools can tackle this in a day or two.