The A5 hits 90,000mi

Back in the fall of 2013 my VW Jetta lease was ending and my fancy consulting job gave me a stipend to pay for a nice car. I went looking for an Audi A5 with a stick, initially used but then found a cool deal on a new S-Line in Daytona Grey Pearl with a 6-speed.

I didn't want an S5, the engine seemed a bit pricey to maintain and the even more expensive RS5 did not come with a manual so that was out even before I couldn't afford it. As it turned out, the 2014s were the last group with a manual transmission.

The S-line was kind of perfect, Quattro AWD, 19" alloys and "sport" suspension, a 6-sp manual and the same TFSI engine that showed up in every VW & Audi made at some trim level. This version is the CAED. To me that meant cheaper & more available parts and more development time/reliability. That has more or less played out over the past 10+ years. The car really hasn't had an issue since I drove it off the lot. Until now. One recall, a new lower sump due to rust, and the seats lost their memory once. Otherwise, brake pads, filters and oil have been it.

Now pushing 90,000mi, I started looking at getting more familiar with the car so I can take over more of the basic work. Before I got anything ordered, the car's first CE light came on. So I ordered up a code scanner, 4 coil packs, the puller tool for the coils, 4 new plugs and a new air filter. Basic tuneup stuff that couldn't hurt. I had lost the coil packs in my old M3 at a bit over 130,000 miles so they seemed like a good proactive fix here.

The initial codes were for a lean condition and an air leak. Online sources seemed to lean towards the PCV/Oil Separator getting clogged. I cleared the codes since the engine was running great to see if they were a fluke - would they come back? I also did a couple of quick PCV valve checks which didn't show anything much going on at idle at least. They can whistle out the square section (pointing towards the rear of the engine) and if you open the oil filler cap while the car is idling it should have positive pressure; if the engine starts sucking air in (and it may stall) the PCV valve is probably stuck.

Replacing a stick with a computerized UI several menus down in the Infotainment system hurts my feelings. This is better. It seems to clear the hood OK.

I went ahead and installed the new air filter. The housing is pretty easy to find on the left side of the engine bay on top. Just loosen all of the bolts (they stay with the cover), remove the air hose (loosen the clamp) and you can remove/replace. I also ordered and installed the new dipstick, and it fits well. Since this engine is in other cars at lower trim levels, it still has the dipstick tube in front of the engine, just capped off, and there is a VW/Audi part for the correct dipstick. I found the part number online.

I didn't get to drive the car for a day or so after and when I did drive it again it had what felt like a miss under full throttle, the car 'stuttered' for lack of a better word. No code though. I drove some more and the engine finally threw a code - for misfire in cyl 1. I cleared it, drove a bit and it then threw it again. The more I drove the more often it happened, and it happened most under heavy throttle which was a little confusing for me. After checking with the pros, when a coil is going, one way you can test for it is to get into a high gear (low RPMs) and floor the gas. They will tend to misfire under heavy load, which is what mine was doing. I got lucky, I had ordered the right parts already.

Step 1 was running out to buy a set of 3/8" Torx drivers since that is what the engine uses. I popped off the top cover and removed the bolt holding down the wiring harness for the coil packs. It sheared. Welcome to the big leagues, lol.

Sheared bolt on left. I'll have to make a date to try and remove it with an ez-out. Luckily it doesn't do much. The coil pack connectors are held on pretty well and there is very little tension on the wiring harness.

Parts:

Dipstick: 06J115611L

Coil Packs: Bremi 20128 / 06E905115G

Spark Plugs: NGK PFR7S8EG 1675 (pre-gapped Platinum plugs)

Air Filter: Mann 8R0133843D

Tools:

Code Reader: Autel MD808P

Coil Puller: CTA Manufacturing 7991

I used a screwdriver to disconnect the 4 coil plugs and then pulled the harness back so I could remove the coil pack for Cyl 1. It came out easily. It was then I realized that these spark plugs are smaller than what I am used to. I do have a 5/8" (16mm) magnetic plug wrench so I was able to replace them. I removed it and installed the new one, torqued it down and moved on. The two standouts were that number 2 plug was pretty loose & possibly leaking a bit (soot all the way up the threads), and number 1 looks like water sat down in there somehow.

You definitely need a magnetic socket to get the plugs in and out, they are way down inside the engine. Don't even try this without one.

The Oil Separator/PCV valve is the round thing between coils 3 & 4 (4 is at top of frame). This is a before pic. The single bolt that holds the wiring for the coils has not been sheared yet.

The PCV valve is the later Hengst part (you can tell by the clear housing next to the round part). There are several different parts so check yours first. Coil packs 3 & 4 have to come out, and there is a breather hose under the coill wiring harness as well as the black plastic hose on the right side running to the intake manifold. Not a big job but stuff to watch out for. There are kits with main piece + both hoses available. My hoses seem great so I am just going to do the main piece once I get another code.

1 new plug & coil pack in place, I had to get the red ones because they look better. The coil puller is very helpful, they are a snug fit and hard to grab. I tightened the new plugs to 30 newton/meters, about 22 Ft/Lbs which is a spec I found online. I checked in with some pros I trust and one thing that came up was misfire codes from plugs that were not tight enough in the newer Audis, BMWs, etc. I will check them in a thousand miles or so or when I do the PCV valve just to be sure.

I had a mouse living under the engine cover at some point and I think that's probably where the rust is coming from, definitely rustier than I would have expected. I chewed up some of the insulation on the bottom of the engine cover.

3/8 ratchet to remove plugs, torque wrench to tighten the new ones, coil puller, 5/8" magnetic plug socket and extension, screwdriver to disconnect the coil harness (pry the release back in the slot on top). The old coils and plugs are cyl 1-4 L to R. You can see number 1 has rust around the top of the plug and the bottom of the coil. Not sure what happened there. I don't seem to have a coolant leak, so perhaps this is from washing the engine? The coils seal the holes with the rubber collars normally.

All done, I have to remove & replace the sheared bolt that holds on the coil connector harness and then install the new Oil Seperator/PCV but first I'll drive a bit to make sure these changes are good. The engine is noticeably happier, it pulls more strongly and revs more freely. It felt kind of sluggish before.

This is a quick and easy job with the right tools; I took about 45 minutes going slowly, one at a time. If you yanked out all 4 coils and all 4 plugs at once you could probably do this in 15min.

Background:

PCV Function & Testing: https://dannysengineportal.com/pcv-valve-how-does-it-work-failure-signs-how-to-test-it/