Replacing VW MK7 GTI Spark Plugs

The last cars I did serious maintenance work on were pretty ancient by today’s standards: a first generation VW Golf (‘78 Scirocco) and several Volvo 240 models. These were all very simple to work on compared to the 2016 VW GTI. When it came time to replace the spark plugs in the GTI, the job looked scary at first. The plugs are buried deep within the engine, and you have to remove the ignition coil packs to get at the plugs. Forum posts talk about the difficulty in removing the electrical connectors for the coil packs, and also removing the coil packs themselves.

This video from ShopDAP shows what is involved:

I did things a bit differently than shown in the video, as noted below.

First, I did the job when the engine was warmed up. I had read that this makes it much easier to remove the coil packs, and that turned out to be true. I was able to remove them easily by hand, without the expensive tool shown in the video.

However, I did buy the ShopDAP spark plug socket, because it is magnetic, and thus is able to pull a spark plug up from its deep well in the engine block.

I also bought (at a local hardware store) a ten inch extension for my 3/8 inch socket driver, because the extensions that came with my socket set weren’t long enough.

Finally, I used standard VW replacement spark plugs (made by NGK), because this car is absolutely stock and under warranty, with no performance mods.

The most difficult part of the job was removing the electrical connectors on the coil packs. It’s not clear from the ShopDAP video how this is done. Some forum posts recommend using a pick to pry the connectors off, but this is a bad idea that can easily break the connectors. Instead, use the trick shown in this video from USP Motorsports:

As shown in the video, you remove the connector in this way: press the connector firmly down, push up on and hold the locking tab, then pull the connector up. Unfortunately, the locking mechanism on connector shown in the video is not same as the one in the MK7 GTI. The following picture (from a MK6 GTI) is closer to reality:

I’ve circled in red the tab that unlocks the connector. It must be pressed upwards (in the direction of the arrow) while pulling the connector out. Practice on a cold engine and observe carefully how the mechanism works, before attempting to remove the connector on a hot engine. Once you get the hang of it, it’ll seem easy and you won’t have to worry about breaking a connector.

However, even after I mastered this removal trick, the connector was still difficult to pull off, due to its sealing grommet. I had to pry up the connector gently, using a screwdriver under the right side of the connector (when facing it from the front of the car), and using the coil pack bolt as a fulcrum.

I also recommend vacuuming up any leaf litter that may be sitting on the engine block before starting this job. I didn’t do this, and a leaf fell down in the well of spark plug #4 after I removed the coil pack. It took me a long time to get the leaf out: the well was a bit oily, and the leaf kept sticking to the side of the well. In the end, I had to smash the leaf into small bits using a BBQ skewer, then vacuum it out using a small flexible tube duct-taped into the vacuum’s wand so that it could reach down into the well.