Jacobn5

I've been having persistent problems for over a year now with my 2.0 tfsi misfiring at idle. More specifically misfiring when the car drops below 1000rpms when at idle, and only when in park. It is running rich and misfires sporadically on all 4 cylinders. In this time frame, I replaced (in this order) spark plugs, fuel filter, diverter valve(the orange seal broke and was causing boost leak only) and all the timing chain parts up to new thread lock bolts. The misfires seemed to start all at the same time but I was still new to cars when this started so i'm not completely sure. These are the current codes on my car
000768-000769-000770-000771-000772-000370
each misfire code says Sporadic: Value of resistance too great
and the Too rich code says Value of resistance too great
and in the past, these codes have come up occasionally -000545-000546-004874-000290-000136
and all of these as well say value of resistance too great
Any advice helps I really don't know where to go from here

SMac770

What is the engine involved? CCTA or CBFA? Have you replaced the PCV? But that it's only a problem in park seems very odd. As well as being rich rather than lean. You replaced the spark plugs but not the coils? Haven't replaced the fuel injectors yet?

As for codes, get VCDS, run a full autoscan, save that log to a file, post the saved text (posting by copy/paste direct from VCDS into a browser window usually means the formatting is all jacked up, same if you do "print", don't do "print" to a file). That should make more sense than whatever the above is.

Jacobn5

sorry didn't see the response, It is the CCTA , i have not replaced the pcv but when i remove the oil cap the car imitates a vacuum leak by which if im not mistaken indicates the pcv valve is fine( might be misinformed). I havent done coil packs as the problem would have gotten much worse by now and all 4 cylinders starting misfiring around the same time, and i have not done fuel injectors. Also currently i am unable to use vcds as i dont have the plugin
the above link is a video of my engine

SMac770

CCTA is basically the transverse version of the CAEB, though technically the CCTA is a EA888 Gen1 engine so there's a bit more to the differences (including CCTA doesn't have VVL on the exhaust cam).

As for the PCV, if it's the original black cap, you should measure 0.6 inHg (20 mbar) of vacuum on the dipstick tube. It appears the CCTA always stayed back cap (current PCV revision is AH), there was no transition to the 100 mbar white cap (current PCV revision AK).

So your idle is fine and remove the oil fill cap, then it idles rough. That's a good exhibit. But it's not specifically a measurement of vacuum per se.

The other thought is carbon build up on the valves, or on the throttle valve. You might look to the throttle valve to see if build up is interfering with closing. And carbon build up on the valves seems to vary widely; I have little of it but others get lots of it. It too could interfere with clean idle.

There might be more in those P codes, assuming they are P codes and not DFCCs, but I don't care to go looking up each of the numbers to see what they represent.

Jacobn5

It is looking likely that i'm going to walnut blast the intake valves and reseal the injectors and intake manifold.

As for the pcv, i was checking it out the other day and inside the hose connected to the intake manifold there was a decent little bit of oil. Covering the intake manifold with my hand i started the car and some white smoke was coming out of the pcv hose connecting to the intake manifold however the engine still seemed to be running rough, should i replace the pcv or is this normal( I have the AH version)

And one more question, would you know what the ticking sound is that starts 6 seconds into the video, it goes away when i revved the engine then came back

SMac770

Sounds like the N80 valve, the EVAP purge valve that manages the pull of charcoal canister vapors into the IM. If you disconnect the electrical plug on it, the sound will stop if it's the N80 "getting old", but not necessary "failed". The PCV is one thing that feeds to both the IM and the turbo inlet; the N80 is the other thing that feeds to both the IN and the turbo inlet (see that small hard line below the PCV to IM hose). On the CAEB, the N80 is integrated into the line set to the IM and the connecting hose to the turbo; a bit of a pita to replace. Not sure if the transverse config is the same.

When you pull the oil cap and it makes that funny sound, I don't have that on mine, that gurgling noise. But your idle didn't seem to get bad when you did that. Doing that on a CAEB that's working, it'll immediately have a rough idle. There should be some oil presence in the PCV outputs (which is why if you disconnect the hoses to the intercooler, you'll likely find some oil there too). The crankcase vapors are pulled through the main oil separator on the block, then through the fine oil separator (what everyone calls the PCV), and then dumped into the intake path (either into the IM vacuum at idle, or the turbo inlet vacuum during boost).

I use a paint stirrer stick to get a better isolation of noises: I hit the N80 at 1:20.

For the PCV, you need to actually measure the crankcase vacuum (vacuum gauge on the dipstick tube), it should measure 20 mbar (0.6 inHg). So there should be some, but almost none. That might be why it doesn't rough idle so bad on "large air intake leak"; the white cap versions the CAEB got later bump that to 100 mbar (3 inHg). I don't know why you'd have any smoke coming from the PCV.