thamlyn

I have a 2018 Q7 3.0T Prestige with about 53K miles. A few weeks ago, I was driving on the interstate when my car shuttered and received the drive system malfunction error. I had it towed in to the dealer and they pulled three error codes for a cylinder 4 misfire, hide cylinder, and misfire during fuel injection. Because they also found fuel residue on the spark plug, they recommended I replace the fuel injectors.

I approved the new fuel injectors and they cleared the error codes. However the engine continued to have issues. The misfires returned. The cleared the code several times to see if it was just due to loss of pressure in the system due to the fuel injector replacement. They checked the compression on cylinder 4 and it is at 3 BAR when it should be at 10 BAR or above. They used a borescope on cylinder 4 and there is no noticeable damage.

At this point, they are presenting two options that I'm awaiting formal estimates on.
1. Tear down the engine to further diagnose the problem. Roughly estimated to "a few grand" but it's not uncommon for an ECRC motor (what's that?) to fail leading to a full engine replacement.
2. Engine replacement.

2 videos from the technician are here if you want to hear his description directly.

The technician and service advisor say it's not uncommon for engines to fail but I'm shocked that I'm having this severe of engine issues for a 4.5-yr old vehicle with a moderate number of miles.

Since I'm just outside of warranty, any thoughts or recommendations? Anyone else have similar issues?

Thank you in advance!
-Tom

TheBudgetBaller

The piston ring for cyl 4 may have given up prematurely. This will likely be a 12-20k repair or 20k for a used engine and 40k for a new one. This is definitely uncommon for CREC engines

kelisko

The exact same thing happened to my 2016 A7 3.0T Prestige with the exact same engine. Cylinder 4 disabled, cylinder 5 and 6 misfiring (see video below). I saw fouled spark plugs like washed with fuel as well. Replaced throttle body, spark plugs, MPI injectors, FSI injectors, flushed engine to no avail. Engine is burning oil like crazy as well and fuel consumption is through the roof. The car is undrivable and is parked for months now. I am still troubleshooting...

mhoran89

I would go back to AoA and see if they will work with the dealer / warranty administrator to give you some kind of goodwill coverage. I bet audi of america comes forward and agrees to pay for 1/2 of the repair. whatever you get from them, get it in writing and also see if you can get them to guarantee the work for at least one year in writing as well. best of luck and keep us posted.

meyergsr

Looks like two options install a new or used engine. The piston rings on cylinder 4 most likely failed. Have you been using premium fuel? Detonation can cause a broken ring.
You could also just trade the vehicle in as is.

thamlyn

Good suggestion. Thank you!

thamlyn

Not pleasant options but I think you're right. I have been using premium fuel.

GDawgA4

My friend has seen 4 3.0Ts over the past year come through his shop for this exact issue. Car runs rough, misfires and found that cylinder 4 had no compression. All stock. Based on feedback from the customers, they were on a drive cruising along then went to pass someone when the issue happened. He suspects the stock software may be running too lean conditions (and maybe together with poor quality fuel from the last fill up) and over time, cyl 4 is the unlucky one. One customer was able to get CPO to cover a replacement engine but the others just got rid of their cars.

kelisko

Happened to me exactly like this. November 2022, was on a trip. I floored it to pass a car. After passing and slowing down a bit, I noticed that something was wrong. Power was gone. When I stopped the car, it was shaking like crazy. Cylinder 3 mainly and other cylinders were misfiring. Later it was mainly cylinder 4 being disabled and mainly cylinder 6 misfiring. Clearing codes did nothing. I did not have the option to tow so I drove it like that back home, about 100 miles. At higher RPMs it was not shaking so I kept the RPM above 3,000 to be able to drive it but it is drinking engine oil and fuel like a boat. Since then I have been replacing obvious components that could cause such a misfire in vain. Eventually I ruled it to be a damaged cylinder block as explained in the video below. I haven't performed a compression test yet. I purchased the tool but accessing the injectors main connectors on bank 2 is a pain. It is clear that some cylinders have lost compression. However it's unclear why this is happening. As explained in the video below, I first thought this is due to the newer cylinder and piston rings design. But I am at 150,000 miles and this is happening to other people as early as 35,000 miles. So I keep troubleshooting hoping there may be another culprit. This is happening to too many cars out there coupled with excessive oil consumption. Most of the time it ends up with a total engine replacement. Crazy! I have decided I am not going the engine replacement route because it is not an option for me. If I can't fix this car, I will toss it. If I find a fix, I will share it but I am keeping my hopes low. What's happening to the Audi brand?

thamlyn

Here's a quick update for those interested. I'm still working through the issue. AoA got back to me a said that anything beyond the warranty is at the discretion of the dealership. I then stopped in a spoke with the service manager. He's worked with my service advisor to build a case. His initial pitch is to cover the cost of the new engine leaving me to pay the labor. My service advisor wrote me an email last week saying, "Audi and our dealership are working together to help with the cost of the repairs. I will be in touch with you once I have received the go ahead to finish the work." Since they don't need my approval to proceed, I'm inferring they are covering the parts and labor. We'll see. I'll post once I know more.