Bit confused. Need help.

[storey618]

So Yesterday I drove the car over to my buddies and hung out all day. I left and came home for a few hours, I then decided I wanted to go to the car wash. Me and the girlfriend jumped in the car. As soon as it started it sounded bad. Like it was dead on a cylinder. It just got worse the more you let it run, to the point that it sounded like it was running on one cylinder. I pulled out motoza and did a quick log which shows afr readings off the chart and ignition angle that's very up and down but still on the graph. I got codes for bad primary o2, lower coolant sensor, p0011, and there was one more code. I think it may have been single cylinder misfire. I cleared the codes and figured lets drive it down the road to see if it clears up at all. When I did this the only codes that came back are 3 cylinders misfiring, and multiple misfire code. It would clear up when giving it gas but would nearly die at idle. I unplugged the maf and it ran the same. Also pulled the plugs and they are white, and the threads are rainbow. I've owned the car for nearly a year and the last time I changed the plugs was around when I got it. So does it sound like my o2 and plugs just decided to go bad? I know I had a p0011 code for timing in there which is what scares me the most. The timing belt was done by the previous owner around 50,000 miles ago.

[crazyquik22023]

So Yesterday I drove the car over to my buddies and hung out all day. I left and came home for a few hours, I then decided I wanted to go to the car wash. Me and the girlfriend jumped in the car. As soon as it started it sounded bad. Like it was dead on a cylinder. It just got worse the more you let it run, to the point that it sounded like it was running on one cylinder. I pulled out motoza and did a quick log which shows afr readings off the chart and ignition angle that's very up and down but still on the graph. I got codes for bad primary o2, lower coolant sensor, p0011, and there was one more code. I think it may have been single cylinder misfire. I cleared the codes and figured lets drive it down the road to see if it clears up at all. When I did this the only codes that came back are 3 cylinders misfiring, and multiple misfire code. It would clear up when giving it gas but would nearly die at idle. I unplugged the maf and it ran the same. Also pulled the plugs and they are white, and the threads are rainbow. I've owned the car for nearly a year and the last time I changed the plugs was around when I got it. So does it sound like my o2 and plugs just decided to go bad? I know I had a p0011 code for timing in there which is what scares me the most. The timing belt was done by the previous owner around 50,000 miles ago.

Tming belt was done 50,000 miles ago, I would definitely be changing that timing belt right away. 60k miles is the service interval. And who knows if the previous owner actually changed it when he said or not. A bad primary o2 can cause driveability issues but usually not like the ones you are describing. And spark plugs just don't "go bad" all of a sudden. I would set timing to TDC and verify timing is correct to start.

[MacFady]

60k miles is the service interval.

Where are you quoting this from? I've never seen that service interval mentioned anywhere. Is this a 1.8T?

[chad99]

You can take a quick easy peek at the top of the belt as well as a few of the belt teeth by undoing those two upper cam belt cover clasps.

[Charles.waite]

Where are you quoting this from? I've never seen that service interval mentioned anywhere. Is this a 1.8T?

This. The actual service interval is here: https://www.audiusa.com/content/dam/...-Year-2004.pdf

Its 75k. which was revised down from 95k or something.

It could be timing I suppose, but my thought is more electrical. A cascading failure like that where all of a sudden a handful of things go bad out of the blue, to me indicates an issue with wiring.

[storey618]

I put motor to tdc cylinder 1 and pulled the valve cover. Timing looked fine to me. Belt looks okay. I've always heard 75k is interval. Plugs, and new o2 did not fix the problem.

[storey618]

Also yes it is a 1.8

[storey618]

Just checked codes again. Had circuit low voltage 16967 (I believe that's what it was) and camshaft sensor code

[imnuts]

This. The actual service interval is here: https://www.audiusa.com/content/dam/...-Year-2004.pdf

Its 75k. which was revised down from 95k or something.

It could be timing I suppose, but my thought is more electrical. A cascading failure like that where all of a sudden a handful of things go bad out of the blue, to me indicates an issue with wiring.

Original interval was 105k, revised is 75k. For the 3.0, one is probably still safe at 80-90k mi, but that would be the furthest I'd push it. I'd stick to the 75k mi interval on the 1.8T just due to the shear number of timing belt issues I've seen posted here.

[storey618]

crank lined up, and cam lined up with valve cover. there are no marks on the chain but from what i count, it is at 16 apart. can anyone verify?

[Charles.waite]

Original interval was 105k, revised is 75k. For the 3.0, one is probably still safe at 80-90k mi, but that would be the furthest I'd push it. I'd stick to the 75k mi interval on the 1.8T just due to the shear number of timing belt issues I've seen posted here.

Amusingly (or scarily) the 2.0t uses 99% the same timing components (the crank gear is slightly ellipsoid vs totally round and the tensioner isn't hydraulically tensioned) and they pushed the interval all the way up to 110k (!!!) miles. Pretty nuts. No way I would trust the belt past 90k...

[storey618]

seriously guys...i need help here. i dont need to hear about the timing belt interval. i have a job and people to support, i need a vehicle to get me to work.

[ozMatt]

Quick google suggests P0011 is usually either the CCT or the solenoid that controls it. However I agree with Charles you had that many other electrical based codes that they may have triggered the P0011.
You need to check your wiring, fuses and relays.
You have two ground connections to check: One on the Valve cover and one on the firewall next to the Coolant Tank. Make sure these are clean/secure.
Check your coil pack harness. Peel back the boots on each connection and check for damaged wires. Might be worth checking the injector plugs as well.

Had any water on the car recently? (Rain, car wash?) Take the top of the ECU box, make sure it is dry inside. Check the relays and there is a 30A fuse in there too.

**I don't know if any of these suggestions may solve your problem, however you've already had the Valve Cover off, these are all common problems, and they do mostly relate to issues you're having, so you may as well make sure you have them all covered off.

[Let it snow]

Have you looked over your vacuum lines and your suction jet pump? Almost sounds like a big vacuum leak.

[crazyquik22023]

Where are you quoting this from? I've never seen that service interval mentioned anywhere. Is this a 1.8T?

I have replaced so many cylinder heads and engines due to timing belt failures on the 1.8t. For me I do it every 60k, I should have said that was my recommended interval, but yes you are right. That is not the actual service interval from Audi.

[crazyquik22023]

seriously guys...i need help here. i dont need to hear about the timing belt interval. i have a job and people to support, i need a vehicle to get me to work.

crank lined up, and cam lined up with valve cover. there are no marks on the chain but from what i count, it is at 16 apart. can anyone verify?

Can not see marks in that picture. Remove the splash cover and take a better picture from a higher angle. But Charles makes a good point above. Check ground connections, especially the main ecu ground behind the expansion tank.

[Charles.waite]

Quick google suggests P0011 is usually either the CCT or the solenoid that controls it. However I agree with Charles you had that many other electrical based codes that they may have triggered the P0011.
You need to check your wiring, fuses and relays.
You have two ground connections to check: One on the Valve cover and one on the firewall next to the Coolant Tank. Make sure these are clean/secure.
Check your coil pack harness. Peel back the boots on each connection and check for damaged wires. Might be worth checking the injector plugs as well.

Had any water on the car recently? (Rain, car wash?) Take the top of the ECU box, make sure it is dry inside. Check the relays and there is a 30A fuse in there too.

**I don't know if any of these suggestions may solve your problem, however you've already had the Valve Cover off, these are all common problems, and they do mostly relate to issues you're having, so you may as well make sure you have them all covered off.

All of this. Especially when our cars are getting older and older, doing engine work requires bending and moving wiring harnesses. The insulation on the wiring, over time and thousands of heat cycles) gets brittle and cracks. When you move the harnesses around it tends to crumble and fall off, exposing the wiring underneath. These exposed bits can short out and cause tons of seemingly unrelated problems, possibly like the ones you're seeing.

[storey618]

so i messed with the car a bit today and noticed one of my coil pack connectors is completely crack (cylinder 2), also i smoke tested... by that i mean i literally took off the throttle body side of my intercooler piping and vaped into it. i found a leak at the boost sensor that is pretty big. along with this i thought i had it narrowed down to the main problem being cam position sensor. i went to a local vw/audi shop in town and talked with the head mechanic. he said he has never had to change one of the cam sensors as they never go bad. he said it seems like a timing issue however, he says that if it was timing it wouldn't clear up while accelerating like mine does. the only codes im getting now are cylinder 2 and 4 misfire and when i moved cylinder 4 coil pack to cylinder 3 i acquired a backfire/pop. i dont know if i posted it last night but after i cleared the codes before work and tried to start the car it would just die, but today when i went outside the car actually started and ran again.

[imnuts]

I'd go with replacing the damaged coil pack connector, possibly all of them depending on how bad the others look like. Install new coils since it sounds like you may have at least one that is bad. And also repair the boost sensor, as that will likely affect how well the car is running. Once that's all done, check for potential boost leaks again, fix any newly found leaks and repeat until they're all gone. Verify the other wiring looks good, then clear codes and see if it is all better.

[Charles.waite]

The highly intermittent nature REALLY leads me to think its electrical in nature. Mechanical problems like leaks are usually steady state issues. An arcing wire can be fine one minute the short to ground the next. Then back again.

[storey618]

im going to cut the wrap off the loom tonight and inspect the wires. i just had a buddy offer me a jetta wiring harness for free, so im going to grab that after work. figure i can either patch the bad parts or completely cut it out and replace it with the jetta one. will be grabbing some rtv to fix the boost pressure sensor leak as well. ill update soon.

[diagnosticator]

When you moved the coil packs, from#4 to #3, (and #3 to #4,) you moved only the coil packs and not the wiring harness connectors still plugged into the coil packs, right? That is unlikely, I know, but that would explain the backfire with the coil packs swapped.

[storey618]

When you moved the coil packs, from#4 to #3, (and #3 to #4,) you moved only the coil packs and not the wiring harness connectors still plugged into the coil packs, right? That is unlikely, I know, but that would explain the backfire with the coil packs swapped.

lol no i moved just the coil. not the wires with them.

[storey618]

also i have a friend coming over with vag-com to check my car this thursday. hopefully i can finally get this shit figured out

[diagnosticator]

lol no i moved just the coil. not the wires with them.

Of course. However, when you said there were backfires after moving the coils, I thought it would be worth mentioning just in case.

[storey618]

fixed coil wire on cylinder 2 and put in a known to work set of 1.8t coils today. ran better but still bad. finally checked boost gauge which i should have done to begin with. car is sitting at 10hg hot or cold idle. which explains my afr being so high when i took the log the first day. think i either have a big vacuum leak or a dead injector. vag com should tell us tomorrow

[storey618]

Cars running again. Last night I came home and vaped into the intake. When I deleted the vacuum lines I put port plugs/caps on all the vacuum nipples. It must have dried out and shot off under boost which explains the random nature of the problem. Thanks to everyone for the help. This is the second time a simple boost leak had drove me crazy and taken my car out for longer than it needed to be