Misfire moving around - help with proper diagnosis

Yeah that was my worry, not sure that everything is lined up from the leak down testing… I dont know how it could go from driving just fine to a single cylinder misfire and complete loss of compression in bank 1, still with only 1 cylinder misfiring. I must be missing something.

I sent the oil in back in March to Blackstone, before all this happened as I had just returned from a year overseas and wanted to get some reading of the motors condition before deciding to put any more money into it. The report came back just fine: <.5% with acceptable values <2%
Report: https://1drv.ms/b/s!Ar5RwRk1fG8zjqgzW-d0O4JEDxuEFQ

I have a local shop coming by to do a house visit tomorrow to bring a scope and whatever else. I told them the rundown of what has been checked and the type of diagnosis Im looking for so maybe, just maybe, Ill get some more answers shortly. Hoping for someone like ScannerDanner https://www.youtube.com/watch?v=uB9XCDO8oa8&index=4&list=PL1Nqs-yZYIJ75svpYUFBYMyS1MX1_Ewnm&t=868s or Shrodinger https://www.youtube.com/watch?v=iHPYGsUOLtQ&list=PL1Nqs-yZYIJ75svpYUFBYMyS1MX1_Ewnm&index=3&t

If you havet driven the car in a long time you can get lifter bleed out and that can take about 45 min of running and driving the car to sort out. In that time you will get a good amount of misfires due to obviously the lifter being down. But and that might have been part of the bad compression test… but that’s a big maybe.

The original mechanic to come out bailed, no showed, and no communication. I called around and couldn’t find another shop to come out but landed on one that sounded like a winner, so I called a tow truck and arranged for it to be dropped off. Tuesday night, 10 hours before the tow truck was to arrive (845am) I put the spark plugs back in after the leak down test, re-attached the intake and whatnot, and then had the car towed to a local shop to diagnose the cylinder 3 misfire. They called on Friday to say that the spark plug is smashed and there is a hole in the piston. It was NOT in this condition when I dropped off the car so now I’m stuck trying to figure out what to do. They are claiming no liability, suggesting that a valve seat fell into the cylinder. I saw the valves when the IM was off earlier and all valves looked fine, though granted I didn’t inspect (can I even see them?) the valve seats. When I started it up after re-installing the IM it idled more or less fine for about 90 seconds before the cylinder 3 misfire started up again, single code. A couple of restarts to check other small fixes and it did the same each time, more or less fine idle for a small bit then the single cylinder misfire would happen. It was a fine, albeit rough (misfiring) running motor when I dropped it off, and now it has a hole in the piston and “smashed” spark plug.

I called another local shop who has done a bunch of work on the car previously and they say the valve seat falling into the cylinder is incredibly unlikely, having to get past the valves before being able to drop into the cylinder. I don’t know enough about this but looking for input.

There are a lot of inconsistencies and issues with their story so far. Such as it sounds they immediately went to trying to drive the car instead of looking at ANYTHING. The car was dropped off without a front bumper, core support minimally installed so it could be winched onto the tow truck. Vice grips clamping a hose closed, wires disconnected and dangling.

Looking for advice before I go back and talk to them further. Currently planning on further explanation, clarity of what their ACTUAL play by play is. I also want to get an actual diagnosis of what was causing the cylinder 3 misfire. They said they think it could be the valve seat that was causing the misfire and then dropped when they took possession and caused the hole in the piston. But they didn’t make it sound like that was their official diagnosis, which is what I paid for, what I contracted them to tell me. So I want them to give me their actual diagnosis of cylinder 3 - do I have a case here for them to do a tear down to find the root cause? Would I trust them? The same shop I’ve used before for work on the car suggested I tow the car home and have a 3rd party mechanic come take a look and do the further diagnosis on what caused the hole in the piston.

Legal action is very unlikely due to the $$ amount. I’ve called insurance to see if they can help at all but not yet heard back.

Here’s a link to photo of the spark plug and a video of their explanation of the ordeal. (I did get their permission to record the convo)

Well that sucks.

Some of what he said is possible but not the valve seat falling in with out the valve falling in as well.

You want to see if the valve fell into the cylinder. That would be what you want to see. There is a chance that the valve seat was going bad and not letting the valve close all the way. That would be part of the leak down issue.

IMHO I didn’t watch past the 5min mark of the video because I kinda agree with the mechanic. Something was wrong and for them to find out what they would have to do certain things to inspect the car and while in the middle of doing all of that whatever was about to go very wrong went wrong.

I’m just stumped because the last time I started it up (after putting IM back, new ignition coils, calibrated injectors, etc) it ran pretty good for the first minute before the misfire kicked in. Here is the link to the video.

After this I only pulled the spark plugs to do the leak down test. I find it nearly impossible to believe that whatever was going on with cylinder 3 to cause the misfire decided that once it got to the shop was a good time to catastrophically fail. The chances of that are theoretically the same as what it would take to start a new planet. It kills me that they took the car and immediately started to drive it instead of checking ANYTHING. It came in with wires dangling, no front bumper, and vice grips on a hose. What about any of that indicates it is something you can just get in and drive without any prior checks? And the timing of the calls… First to ask about the spark plug being cross threaded, then 11min later to say the spark plug was “smashed” and a hole in the piston. It doesn’t add up.

1:20 - primed, resting PSI up to 30
1:40 - continue priming fuel pump, resting PSI rises to about 60psi then drops to a resting point of 55psi which I believe is what it should be
3:05 - put garage door up before starting the car, clicking noises following are me logging into VCDS and setting up some measuring blocks. PSI is staying relatively steady. Drops to ~50PSI before starting
7:52 - start motor for first time since having removed and split IM, replaced oil check valves, cleaned/calibrated injectors, new ignition coils, etc. Started up RIGHT away and idled as expected (a bit rough) for everything that was removed and worked on. Fuel pressure was steady at 60psi while running
8:49 - misfire begins on cylinder 3, starts running very rough just like before all of this. Put me back to square one as I thought I was doing okay with the first ~1min or so of it running.
9:48 - turned it off

From that aspect I agree it shouldn’t have been started.

While I can’t say for sure what happened I would point out that all of the issues seem to have pointed to cylinder 3 before and now that there is catastrophic damage its on cylinder 3. If you had issues on say a cylinder that had no issues before this. I would lean more in the direction of possible issues from the shop but something serious was going on with cylinder 3

You would have to tear down the motor to really get a good idea on what happened and what went wrong.

You might have had a bent rod that could cause issues and remember on cold starts misfire reconition isn’t on right away. After the car turns on and comes into closed loop that will read off all of the sensors and start showing signs

Quick update for anyone that might be interested…

Got a replacement engine from wrecking yard, had a forum member take a look at it prepurchase (thank you Vinny!) and have been slowly tearing into it, prepping for a new life in the Avant.

On the old engine: I stripped the upper oil pan locking bolt (t45) when trying to remove it so I could insert the crank lock pin/bolt and take the chains and heads off. Also broke off a bolt extractor trying to get it out. Waiting to get a nut welded onto the face of the bolt head and then I’ll finally get to see what really happened in there. So far I’ve shaken what looks to be valve keepers from the intake manifold.

WOW well great work. It sucks that all this keeps coming up but now that you have two motors you should be able to really get everything you need to get the car running strong again.

What a disaster! good luck on the rebuild

Thanks! Getting there… just had a machinist re-cut a 30* face into the exhaust valve seats to recenter the valve on the seat. Looks like it had been wallowing out the seat and was only going to get worse. Valve guides are measuring at 0.6mm when limit is 0.8mm so it’s close…

When I took the heads off this is what the pistons/bores looked like (some carbon chunks, oil) from sitting for 18mo or more. I hope no carbon really got stuck between the top piston rings when rotating the crank to TDC before taking the heads off.

What do you guys suggest for cleaning the gunk out of the bores without getting carbon damage at the piston ring? I was thinking an overnight soak in two pistons that are higher up on the stroke so that when rotating down the carbon is soft and wont do damage. Not sure what’s best. I’m a newb and this is all new to me

https://yd5bqa.bn.files.1drv.com/y4mAgYtWPfoRogShvZuqXOi7ov0ZVVL3ncntDNcj3YWAbzlKmUODWDWsoy_lVxO85KMIpMTw8yDgh1QHpU4lvKn90GGhqTcQA2PUeIs4gE8HNvaLu0Cvo50tnl_bpAYggkXw7klH3pGSSpHV5r4CcR0-BdbCRyZrBaa8Z64j09QVo2MmSJHZTDAif7jwwES73BFK4hT_z5E3su-JuDox8oBNQ?width=1024&height=768&cropmode=none

https://bqqnsg.bn.files.1drv.com/y4mCeWi3hrIpmTaaM0In0FeNYn7Ms8K27IufMhT8WrTAgg0817CDHIhBTwdya3_KL3ycVK2Fpv5z1aTAWG-4QroA6AtUm6DekjPQrgolUZFnRv_rlQWSS7UR3nNr7X7_bgtUVzt_-2AqQZ_BaMBj5gMSflJBcNZjrWU1M_kX7sHM3NF6tie_2AM-OVtlJ4U-rsQ-1Lz34J_IOZC8PTArL4t4g?width=1024&height=768&cropmode=none

OMFG those 4 cylinders look terrible.

A good soak at TDC position would be best. If you have the oil pan off I don’t think it would be as big of a deal.

Haha yeah, don’t look great but they do look worse than they actually are! Wipes off easy enough and I’m honestly not worried about getting the pistons looking nice.

I just want to make sure I’m doing the best thing when rotating to TDC the pistons that are already at the bottom, or lower down on their stroke. I want to make sure that I don’t do any damage if any carbon chunks already got stuck between the top ring and the bores when initially rotating to TDC for removing the heads, etc, because yea, as you noted, this looks pretty nasty and it was all in there when I was initially rotating that little bit. Maybe I’m paranoid?

Google photo links
Initial Piston/Bore Inspection
https://photos.app.goo.gl/hbSFgd7bFwHHgvXB6

Closer Piston/Bore Inspection - Minor, careful cleaning
https://photos.app.goo.gl/ppRvZAh7izatYeVD8

WTF the one side 5-8 looked terrible.

spray penetration lube on the topside of the walls and the bottom side under the piston then free spin the motor to make sure there is no carbon bits in there use an air hose to blow between the pistion and the walls.

First start: https://photos.app.goo.gl/vyA8ZVVxnu3pDpav7

Update!
Started it up last week and it seemed to be great, at first, then I realized the loud tapping wasn’t going away.
https://www.youtube.com/watch?v=zK6F7jcsTtE
https://www.youtube.com/watch?v=BhtwxjQp6fI
After a lot of consultation the consensus said it was likely collapsed lifters that haven’t pumped up yet. I got a mechanic’s stethoscope and turned it back on for the first time since Friday and let it idle twice for a total of maybe 5 minutes combined. Couldn’t exactly pinpoint the noise but it is definitely most pronounced in the back of bank 1 and there is some noise in the front of bank 1. Bank 2 is fairly evenly quiet across the cylinders. Definitely not the same ruckus as bank 1. The noise is most pronounced around the cam sprockets and cylinder 4 rockers/lifters/valves. Pulled the oil cap to check and make sure oil was flowing around and it began to idle very rough and almost die out. I put the cap back and turned it off. Bank 1 spark plugs are brand new and still look brand new. Noticed first leak of the job - a coolant leak around the passenger side aux radiator. Haven’t investigated it yet but it was enough to get my distilled water and remnant coolant mixture to boil (or maybe just a strong simmer) in the overflow tank.

Bank 1 valve train looks somewhat fine from what I can tell without removing the camshafts. There is maybe heat scoring on the edge of some of the intake lobes:

https://cufjrq.bn.files.1drv.com/y4m4OhxBfo-omjlGfKP9P-b4pgarTZ6D9gTbRofFInfOdHn-_frveOH9T6N11RXc_EAaZlYKNJzUPvONGmMa15u2BCbN1QHjasVN7DUkOjPZoFzMrcCWG9iTp-ipwxLo3xFDFoFIaMyLc5geyesjYz-fwfwfP47clUKkt8AtJaFJkDZSa41G2ObGyS6XlPUrUaNAf7RlB6cGgmKvg-akWqm7A?width=660&height=495&cropmode=none

How they looked right before the VC went on:

https://qmqyig.bn.files.1drv.com/y4m6ge4Icj2wP41z7VInL1FzjDVj3381mfgvCoDhpRI5nSmBkeyLLgoV9hGX5qGKrZFFEwjNL2Mf41k8T701yPA2MnCk9UEBZemkv7Ucw4dddN4nKSo-RY8coEAIKcvXk_yik58K2PlFd7Tq1HNYa_JG4NhWASPsVDUqeGlcbmGcf-uY_AkKYWc7kjOoqIGzm82SwHfbI0KRQqLVmgK_JeMUg?width=660&height=552&cropmode=none

Bank 1 timing chain is taught as can be and at least both the intake and exhaust cams are aligned - haven’t taken off the bank 2 VC yet to confirm timing hasn’t jumped. I can’t find anything that looks off when I stare down into the timing chain cave from the top of bank 1.

https://dvyl6a.bn.files.1drv.com/y4m_JtM7TOBTinanuUE5FdJfi8UPgOw2NDu2VzyPUTvB4j-CrHeSIX5GXwfqU3oWl7-JkjWC7gZVgHTpeLLJAM4df2ebPlzy2rwgK7RgXAMKqGTIt1B0kYSV1A9Ok3ddmvrBzX0HXPXVGJnZc_12ea03LC5bxgSzJqmH7ERZtG-Z5ya4DgjAZD0v_FqX2UQJgSYdwgttYSal9eaMBY5PaOYYA?width=660&height=495&cropmode=none

I was hoping to find some obvious mistake, and maybe it’s still there and I’ve missed it. I guess there is still the possibility that the lifters haven’t pumped up? I took a closer look at some leftover lifters and I guess I don’t really understand how this issue of the lifters needing to fill with oil really applies to our particular setup. Can anyone help explain or have any thoughts?

Couldn’t get to the bank 2 VC tonight (stupid oil dipstick bolt)
Will test your theory on cylinder 4 piston to see if it’s anything obvious on the bottom end.

Also, the pcv is new.
Open to any and all thoughts!

Ok watched the first start video and you have either a loud injector or a lifter still not up. I helped a friend recently that had his car parked all winter start the car and get all the small maintenance done. When we started it… it sounded just like your car.

Get the vag com and if there is one or two cylinders that are missfireing now check them with the vag com. ITS NORMAL for motors that haven’t been started in the past 6 months to have a lifter that leaks down.

On the car I worked on it took almost 1/2 an hour for the lifter to pump back up and then the car ran fabulous.

How long did the car run for.

Your wife sounds very supportive.

Hey good to hear from you - hope you’re doing well!

Total run time is roughly 10 minutes by now, 2 minutes of actual driving and it felt great with minor pulls to 4-4500rpm (last Friday). Would it be able to count misfires with this little of run time? I know it is groups 15, 16, 17 for misfire counts. (newb questions :slight_smile: )

I took VC off and dry cranked it a few times, posted a new video to YT. Can’t really hear it with the VC off, everything looks and sounds like it’s moving well. Oil is pumping out of the rocker levers. No metallic noise.
https://youtu.be/N2tj4iZfN5E

Was given a good thought to look into from Vinny on AZ that it could be the new chain tensioner. In this video I’m focusing on the bank 1 timing chain tensioner.

The tensioner moves around quite a bit but I don’t know that I’d call it noisy. Other than this, I’m at a bit of a loss other than, like you said, it being a lifter that hasn’t pumped back up. This replacement engine sat for over 18mo by now and they were installed and head bolted down about 1mo prior to starting (assembly lube was used!) There is a good thread here with a brand new bank 2 tensioner failing but that moves around quite a bit more. Doesn’t mean mine isn’t bad. https://www.audizine.com/forum/showthread.php/757695-Do-any-timing-chain-experts-have-advise

Ran it with the valve cover off. Tensioner looks stable and taught. Not sure where the sound is coming from if it’s timing related. Could still be a lifter…? Does the exhaust cam sprocket cap/bolt look concerning or is it just the optical illusion from the cap not being perfectly centered? i quadruple checked the timing with the T40047 setting gauge several times after everything was torqued down. no issues installing torquing this cam bolt. I did find that one of the new bolts I received was bent from the factory but that was caught and replaced.
https://youtu.be/hLDZbPOPRMQ

Suggestions? thoughts? I’m willing to test just about anything before pulling the engine. Including putting it back together and just driving it :slight_smile: I really don’t want to blow this one up so if driving it is questionable, that would be good to know.
Dry crank video for quick reference and comparison:
https://youtu.be/N2tj4iZfN5E

YT playlist being updated with videos.