The other day I start my day as I always do, I get in my car and start to go to work. I get about a mile from my house and the check engine light in my Jetta starts flashing, the car starts stuttering, and I pull over to the side of the road. I’ve been visited by Murphy a lot in the past and I always assume the worst. I intantly think the turbo has gone bad and will need to be replaced! After getting my senses back, I turn the car off, wait a minute or two, and turn it back on to see if that helps. Of course it doesn’t, so I limp the car back to my house and park it. I call my boss and he is able to pick me up to go to work.
So now I am thinking about what could possibly be wrong with my car. All day long I come up with possible scenarios, the spark plug fouled, the coil pack is bad, the turbo is all screwed up. On and on speculating on the causes of the check engine light and sudden stuttering of my car, really just working myself up and stressing myself out.
As soon as I get home I plug in my Actron Pocket Scan tool to see what the trouble codes are. On the Jetta, the port is under the dash on the left side of the steering wheel. It turns out to be a P0304 error code stating that there is a misfire in cylinder 4. Ok, so what is my next step…..Since I change my spark plugs pretty regularly my thought process was that it was not the spark plugs, this is not to say that I couldn’t have been but there were less than 30k on them and they didn’t fail after installation so I moved on past that possibility. If the following test did not return results, I would have pulled the spark plug from cylinder 4 for inspection. At this point I decided to swap the coil packs from cylinder 3 and 4 to see if the code moves over to cylinder 3.
This is pretty easy to do, all you need to do is remove the plastic cover from the top of the cylinder head, then unclip the electrical connections from the coil packs and slide them off. Then the coil packs just get pulled up off of the spark plugs. Put number 4 on 3 and 3 on 4. I quickly erased the codes on the computer with my Actron tool and started up the car.
Plastic Cover Of VW Jetta Engine
Plastic Cover Removed
Unclip the electrical connectors by pushing down on the “button”
Move the cylinder 3 coil (green) to cylinder 4 and move 4 (red) to 3.
Grab the coil pack and pull straight up to remove
Sure enough, the code moved to cylinder 3 indicating that I had a bad coil pack. I went online and found Standard Motor Products Ignition Coils that were not too expensive. Since the price of these coil packs were reasonable, I decided to replace all four of them instead of waiting for the other three to fail.
Within two days I had the coil packs on my doorstep and was able to replace all four of them. No tools required! After installing them, the check engine light never came back on and a test drive confirmed that all was well! Now if I can only get that pesky window washer light off! I also purchased the window washer sensor when I ordered the coil packs! There will be another post on that shortly!
The Standard Motor Products Ignition Coils failed after only about 10,000 miles. I have since replaced them with the R8 Ignition Coils after getting the same Check Engine Light issue.