Misfire on cylinder three?

Hi,

Yes, a failed spark plug can cause a misfire. Are these original spark plugs, or have they been replaced? If they are original, I would replace all of them. I don't know if you need them, but I attached the directions below.

Also, keep in mind there could be other causes. For example, a faulty fuel injector or there may be no power to the coil. Have you checked those things as well?

Let me know.

Joe

See pics below.

Hi,

Which cylinder only has 30 psi compression? As far as carbon, it is something that is possible. For compression to be that low is really odd with this many miles.

I know these vehicles are known to have timing chains that stretch. It could be an issue, but that is really off.

Let me know what the readings were from each cylinder. Also, you may want to remove the valve cover to see if the chain is loose.

Let me know.

Joe

Hi,

That is correct. You can perform a wet compression test which indicates if it is a ring issue. However, at 30 psi, I didn't feel the rings were the issue. That's why I didn't recommend it.

At this point, the only thing we can do is remove the valve cover to see if there is anything that obviously stands out. If you still have 30 psi, a valve would have to be nearly closed because if was excessively open, you would have 0 compression. Also, there is a chance (slim) that the head gasket has failed.

Also, although you don't feel the misfire at a higher RPM is simply because of the engine speed. At 30 psi, the misfire is still there. It just can't be noticed.

Let me know your thoughts or if you have other questions.

Take care,

Joe

If you check the cylinder 3 valves, do they appear to be fully closing? You may have to turn it by hand a bit.

Also, nothing is easy on an Audi. LOL I always say the first step to any engine repair or service is "remove engine."

Let me know.

Joe

Hi,

Is it possible for you to get a clearer image with the borescope? I couldn't make out things too well.

If you can't get a better pic or tell if the valves are closed, other than removing the cylinder head for inspection, there isn't much we can do.

Let me know your thoughts. Also, let me know what I can do to help.

Take care,

Joe

Hi,

Wow, that is a lot. Now that I see that, I suspect we may have a valve not fully seated. Are you able to get it cleaned out at all?

As far as the torque specifications, I added them below. Make sure you follow them in the three-step process indicated. Also, don't overtighten them. Make sure the surfaces are clean and dry before installing the sealant.

Let me know if this is what you needed.

Take care,

Joe

See pics below.

Hi,

That's a good question. LOL Install the cover, turn the crank to TDC, and remove the cover to see. If it isn't aligned, install the cover, turn the crank 360 degrees, and check again.

Honestly, I don't know who comes up with these designs. I have an old one, 2005 3.0L. It's a lot easier to work on.

Joe

Hi,

I wouldn't want to remove it again either. What a nightmare. LOL Years back, I had a beautiful A8. It developed a coolant leak at the oil cooler. A 3" plastic pipe with o-rings on each end needed to be replaced. I think the parts were under 20.00.

Step 1 in the manual was, to remove the engine. Ugh! LOL Well, I'm too stubborn to do that, so I worked around that and did it in 3 hours. Just FYI, the manual called for 24 hours of labor which included the removal of the "liquid-cooled alternator." Yes, 24 hours.

When they break, they can be a headache. But when they are right, nothing drives nicer.

Let me know how things work out for you.

Take care,

Joe