thanks for the info and link. Glad to hear (I think) that the oil/drivers side may be unrelated to the main misfire issue at hand.

In looking at it a little bit further, I've now realized that my breather hose setup is basically trash. Really brittle, broke in the front/center of it, and also has a fair amount of dried sludgy stuff in it. Assuming that this wouldn't be cause of misfire, I'll wait to replace this until its back up and running.

Thanks again for your post

 

Also curious what the digits after the dash of the main codes means. For example, when I first ran scan I got:


16684-35
16686-35
16684-163
16686-163

Now, I just went out and 1) cleared codes, 2) swapped the misfiring cylinder's (#2) wire with another wire, 3) started/ran engine for a minute until CEL light came on, then 4) rescanned.

Here is what I got:


16684-35
16686-35
16684-35
16686-35


So what is "-35" vs. "-163 ?

 

I don't know what the extension is on those codes. RossTech doesn't say anything about them. But...go back to RossTech and read the possible causes for 16684.


16684/P0300/000768 - Ross-Tech Wiki


First one is air intake system leaking. That's what your crumbled breather system is, a big leak. I'd start with shoring up that. I've been known to put it back together with heater hose and clamps. Bshusted put me on to this pipe and I completely redid mine for about $50. Looks nice and will never crumble. As long as you're doing it take off the check valves on the back of the motor and clean 'em out good with gasoline. I'm not sure this is the cyl 2 misfire, but it would certainly account for the random multiple misfires.


It's going to be a balmy 30˚ today Ryan!

 

Thanks for the tip on the hose. ?, your hose looks to be metal (silver color), but when I search heater hose all I see is black rubber hose. Can you clarify what it was that you used, please?

 

Yea if you want to just get it running again, black heater hose in the bad spots with hose clamps will do. Bshusted here (I'm blaming him) got me going on rebuilding the whole thing. I went to McMaster Carr McMaster-Carr and ordered pipe, plastic tubing to transition to the existing plastic connectors and clamps.


89965K273 Multipurpose Aluminum Tubing, 5/8" OD, .555" ID, .035" Wall Thickness, 3' Length 1x10.85 = 10.85
52315K251 Extreme-Temperature Tubing Made with PTFE, 5/8" ID, 11/16" OD, 1/32" Wall Thickness, Black 2' 7.86/ft = 15.72
52545K25 Gap-Free Pinch Hose and Tube Clamp, 39/64" to 47/64" Clamp Diameter Range, 9/32" Band Width, Packs of 25 1x10.83

 

I've installed / done;
- new stock breather hose assembly
- 6 new plugs
- ohmed across coils/wires and confirmed to spec

Assessment:
Seems to start and run much better. Will idle in place for seemingly ever. Even with throttling up rpms

However, when I test drive it almost immediately throws same codes 16684 and 16686

I am tempted to throw $160 at it and buy a new coil, but know that isn't the smart thing.

Thoughts / suggestions ?
-

 

If you've done all of Bentley's tests on the coils, I'd tend to move to other possible problems. Keep in mind those coils are wasted spark coils. That means when 2 gets a spark, another cylinder (5?) gets the same spark but in the wrong part of it's cycle. So if the coil for 2 is bad, you'd get a misfire on a cylinder on the other side.


1. Fuel problems
2. Light a cigar (a good one, cheap ones suck) and blow smoke around all the crankcase ventilation system and intake and see if the smoke gets sucked in somewhere.
3. Swap injectors to see if the misfire moves.
4. At some point you have to consider a compression check for the number 2 cyl, but I'd want to swap injectors, etc to see if the misfire moves first.

 

audi/vw are tricky for misfires. if you got the specific resistance necessary, it could be the ecu. (last resort) Your 30v means your icm is built into your coil. with good resistance and no adjacent misfire, as already stated by another member, i would move on to what supplies the coil with needed input. ecu, crank angle, cam position sensor, and the physical connector to the coil. your accordion tube intake isnt cracked or broken? you looked into oil on the plugs further? cant expect a plug to fire saturated in oil or gas.

 

Thanks. I need to research injector DIYs now, don't know anything about then yet (or how to swap )

Re: your comments on "wasted spark" and problems showing on opposite side. Is there anyway the oil on drivers side (when I pulled out plugs) could result in misfire error code on other side ?

I'll do he smoke test when I have time and can work on it again

Thanks

 

Hi thanks for posting.

I just replaced the breather tube assembly which I think is what you are calling accordion. I'll do that smoke test to see if I find leaks

The oil was found in drivers side plug holes (4-6). My misfire code is for #2. Could that be related given opposite sides ?