Plugs and Coils Replacement
I had been planning to replace the plugs after having the 25,000-mile service done. Since the consensus is that the NGK BKR7EIX Iridium plug is the best choice, I ordered a set of 4 from an eBay vendor. They were $40 for a set of 4 + $2 shipping via USPS.
Note: There are variations of that plug model number with e.g. '-11' or other suffixes. They are not interchangeable. For the A3, you need the BKR7EIX exactly (they are correctly pre-gapped to 0.030"). These are one heat range cooler than the stock plugs.A coil failed right at my 25K service
, so as soon as I got the car back from the dealer I replaced the plugs. Since the coils are removed to reach the plugs, these instructions also cover coil replacement.
- 5/8" (16mm) spark plug tool
- Wire-type plug gap tool
- T-25 torx driver
- Unplug the Mass Air Flow (MAF) sensor.
- Undo the spring clips and pull out the turbo inlet connector.
- Remove the two T-25 screws on the air snorkle as shown below.
- Remove the engine cover by pulling up HARD where indicated by the green circles in the photo below.
Release the clips on the 4 electrical connectors to the four coils, and carefully move the harness out of the way.
The Coils are not held in by any clips, you just have to pull them straight up. It may help to make a small strap of cloth to slip under the edge of the cap of the coil to give you something to pull up on, rather than trying to pry them up to get a grip by hand.
If you're just replacing a coil, do so now and put everything back together. If you're replacing plugs, then use the plug tool to loosen and remove the four plugs. If you have access to compressed air to blow dust/debris out of the plug recesses before
you remove the plugs, that would be a good idea.
Check the gap of the new plugs before installation using a wire-type plug gap tool. They should be pre-gapped at 0.030". Do not change the gap, as you can damage the centre electrode.
Reinstallation is the reverse of removal. When installing the new plugs, spin them in gently to avoid cross-threading. Once they are finger-tight, tighten them down according to the instructions on the packaging (~ 2/3 turn). Insert the coils and press down firmly until they seat - there isn't really a tactile 'click' when they're seated. Make sure the wiring harness is plugged in securely and each connector 'clicks' locked.
The rubber grommets on the underside of the engine cover may have popped out during removal, make sure they are completely seated into the cover before pressing the cover down onto the 4 posts where it mounts.
It may be a combination of things with the new coils and new plugs, but the engine now feels like it did when new - it had (subjectively) lost some of that feeling over 25K, so I'll probably make plug and coil changes a regular maintenance item every 25K miles now.
UPDATE: November 2008 - Click here to see what these plugs looked like after 25,000 miles of usage.
Labels: HowTo, Maintenance, Upgrades
The week before Christmas we drove up to Vermont to spend a few days skiing. We returned, and then went up into Pennsylvania for the few days around Christmas, then back. A lot of driving over those 2 weeks, no indications of impending trouble at all.
For New Year's we went back to Pennsylvania, but a couple of days apart, so we took separate cars. On New Year's Eve as I was driving up there, I was about 5 miles or so from my destination when suddenly the car started misfiring and losing power. The 'Check Engine' light (CEL) came on flashing, but then changed to a steady indication. Then the misfire cleared up and the CEL went out, and the engine was back to normal running. This repeated a couple of times over the next 2 miles, then the misfire became continual and did not clear up, and the CEL was on in a steady indication (not flashing). As soon as the misfire occurred I knew that I was the victim of the infamous VW/Audi coil failure. I limped the remaining couple of miles to where I was going, running on 3 cylinders and regretting not having gotten a spare coil to carry around like I had thought about doing.
VW/Audi use a 'coil-over-plug' system for many of their engines. That is, instead of a traditional single ignition coil and distributor system with traditional 'plug wires', each sparkplug has an ignition coil directly clipped to it which is then connected to the vehicle wiring harness using standard wiring. 'Ignition wires' in the old sense are eliminated. While there are some technical benefits to this concept, it is simply bad from a reliability standpoint. That is, whatever the failure rate for one
coil is, having four
of them on your engine increases the probability that you will experience a failure of at least one
of the coils.
The coils themselves are easily accessible on top of the engine, and can be replaced with no tools and without getting dirty in a few minutes. That is, if
you have replacement parts...
I weighed my options in this situation: The next day was New Year's Day, and dealers would all be closed. If I called for roadside assistance they would tow the car to the nearest dealer, and that was over 2 hours from home - not what I wanted to do, but it looked like the only way. At least my girlfriend and I had driven up in separate cars so getting home wouldn't be a problem. The next day when we were ready to leave I decided to give it a try and see if it would run. It started up right away, idled smoothly, and had no CEL. I decided to go for it. If it died on the way, what's the difference in calling roadside assistance from the side of the road vs. where we were staying? I knew where two Audi dealers were on the way home, and planned to drop it off at the closest one to home who had already serviced the car before. Since she was following me in her car that would work out fine.
About an hour later the misfire and CEL returned. Luckily this was right near the exit where the first of the Audi dealers was, so I exited and went a few blocks to Don Rosen Audi. They were closed, of course, so I filled out a night-drop form and left the key. On the form I indicated that a coil was bad, and to go ahead and do the 25,000-mile service since it was due in a few hundred miles anyway.
The next day I got a call from Katie, a service advisor at Don Rosen Audi. She said that TWO coils were bad, but they had none in stock and the closest ones were in Canada. It would take TEN DAYS to get them, and I shouldn't expect to get my car back for TWO WEEKS. I asked about getting a loaner but she said the best they could do would be to arrange me a discount on a Hertz rental. I had no interest in spending money on a rental since I could borrow something for a few days. I didn't get mad at her since it wasn't her fault, but after I hung up I was so pissed off I couldn't stand it.
VW/Audi coils are crap. They've been failing for years and years on the 1.8T
and now on the 2.0T engines, and they still can't seem to get it right. Knowing how many they replace, why are there none any closer than Canada?
Speaking of Canada.... TEN DAYS to get them shipped?!?! What part of Canada are they in? The Northwest Territories? Being hoarded by Inuits? Are they being shipped by dog sled?!? It's a small package that DHL could deliver anywhere on the planet in under 48 hours, so to claim 10 days from Canada --> Philadelphia is absurd.
I immediately called World Impex
since they were the closest (=shortest shipping time) online parts vendor of the ones I had dealt with before. They had 2 of the coils in stock, so I ordered both of them and called Katie back to say that I would have the parts in 2 days. She was shocked, but very accomodating and agreed to hand me the warranty-ordered coils whenever they came in since I would supply these two coils up front. She verified the part numbers, and got the contact info for the vendor from me (pointless, since I had gotten the last two they had in stock). Two days later when the coils arrived I dropped them off at Don Rosen and got to meet her - she was kind of embarrassed that I could source the parts faster than she could!
But wait, the story doesn't end there....
I got the call that the car was ready, so I went up to get it on that Saturday morning. There was only one guy in the service area (Mark) and he was rushing to take care of several customers. I got my keys, and was told that they had decided that only ONE coil was bad. I went out to my car (Katie had left my other purchased coil in there for me), and decided to pop the hood and have a look before I drove off. What I found was the engine cover completely broken (and no, it wasn't that way when I took it in!) so I took a couple of photos with my phone:
...and went back to see the guy in service. He was busy with another customer, so I said for him to come take a look at something when he got a minute. A few minutes later he came out, took one look at the engine cover, and realised why I was really unhappy. Without hesitation he offered to swap my broken engine cover with one off of their A3 courtesy loaner (and put my air filter and MAF sensor in it) since they didn't have a new cover in stock (at this point I'm wondering if Don Rosen Audi has any
parts in stock). He had one of the techs do the actual swap, took care of the warranty paperwork, and I was on my way shortly.
To wrap up the Don Rosen saga: eventually they received the coil that had been ordered under warranty, so Katie boxed it up and mailed it to me. I also got a call that the engine cover had come in, but since there was absolutely nothing wrong with the one I now have on my car (once I detailed it), we agreed that I would keep what I have and they would use the warranty part to fix their loaner. I'm satisfied on both counts.
The customer service experience at Don Rosen Audi was a mixed bag. Katie & Mark were both very helpful, professional, and generally 'did the right thing' without giving me any BS. It's not personally their faults that the parts weren't in stock or that the engine cover was broken. Katie giving me the warranty coil without question (in return for me supplying the coil for the immediate fix) and Mark swapping the engine cover with no hassle were the only
things that were positive about the experience. The whole 10-days-shipping/2-weeks-downtime thing, on the other hand, was just really stupid. If I
can find the parts within 15 minutes, they certainly should have been able to as well. Did nobody stop to think "I can't tell a customer something this rediculous with a straight face - what else can we do about it?" They could have used Google
. They could have pulled a coil off an A3 on the lot, or expedited the shipping. They could have done a lot of things besides thinking I should pay half a month's car payment for my car to sit on their lot because they can't seem to adequately stock high-failure-rate parts.
On a larger level than the dealer, the coil failure situation makes me very unhappy. What if this had happened while we were on our trip to Vermont 2 weeks earlier? Rental $$$, logistics of the car being 6 hours away from home, lost vacation expenses.... To get around the risk of this happening again I'll be carrying spares from now on.
Audi replaced the coil on the No. 1 cylinder under warranty. Since I had ordered 2 coils on my own, I went ahead and replaced the coils on 2 and 3, and ordered yet one more coil from Impex to replace No. 4. I now have all four new coils in the engine, and the old ones are packaged and stored in the car back with the jack and tools. I don't ever have to worry about being stranded by a failed coilpack again. If some company eventually makes upgraded coils for this engine, I'll change to those and get rid of the OEM junk altogether.
The original coils were all part number 07K 905 715 with no suffix letter. The new replacement coils are part number 07K 905 715 C
. I hope the fact that they are 3 revisions newer than the ones I started with indicate that they are more reliable. We'll see. Even though I had the earliest part number in the car originally they would not replace all the coils, only the failed one, and would not replace the plugs even though I asked. I did the plugs separately later. The procedure for replacing the coils and/or plugs is in my article on plug replacement
Last part of this rant: When I first got the car it idled so smooth you couldn't feel any vibration inside at all. Over time I started noticing a slight bit of unevenness at idle. I asked the dealer about it at the 15,000-mile service, and got the standard "...cannot duplicate..." and "...they all do that..." answers. After replacing just the one failed coil, it was back to idling like brand new again. (EDIT, about a month later: the slight uneven idle is back, but not quite to the degree that it was before the coil replacement.)