[tagraf]

AWM Engine Misfiring; what is that noise?! Video included with details!

Hello everyone!

Quick story -- the Passat started misfiring. It got to the point where it couldn't keep running when throttle was pressed. Had to tow it to a shop. Some $300 of labor later, they indicated there may be an issue with the timing but couldn't verify it. They wanted $700 for it. No way, Jose, I decided to take it back and take on the work myself.

The problem is that I'm deaf. I need your expertise in listening skills; please see the long video to see if any of this makes sense. Point them out and I'll rip into it. I have got to figure this out because I can no longer leave the car on my property broken (it's been like this for months! ).

Specs of this car:
Year: 2003
Model: Passat B5
Platform: AWM
Engine: 1.8T

I already have it all taken apart -- just need additional insight.

Thank you!

 

[tagraf]

Here are the pics:

 

[Tomvw]

First thing is to scan it and post all of the codes.

Someone with a stethoscope would be a great help to narrow down where the noise is coming from.
To eliminate parts, remove the accessory drive belts one at a time.

 

[Hirnbeiss]

That's an unusal sound to be sure, but it may be an effect of the misfiring rather than a cause. Was the AC on at the time?

 

[tagraf]

Hey all, sorry for the delay in my response! I had been so busy. I had it scanned some months ago and it did not come up with anything useful other than "MISFIRE" on all four cylinders.

P0300
P0301
P0302
P0303
P0304

I do not have anyone around with a VAGCOM now to assist me. I also took out coolant and cannot put it back together to start it up again. At this point, I'm looking for some common causes and want to identify it. The local VW shop told me that timing is likely off. So I need to know how to determine that. Any tips?

 

[Tomvw]

It is likely you have vac/air leaks causing the misfiring, check check intake, vac lines, and PCV system.


Timing:
Turn the crank to align the TDC mark on the pulley with the mark on the bottom TB cover, check the alignment of the marks on the cam pulley and upper rear TB cover.
If about 180 degrees out, turn crank one full turn and re-check.

To check the timing chain you need to remove the valve cover and check the 16 roller count, also check the timing marks on the camshafts & bearing caps.

Check the 16 roller count as shown at the bottom of this link: (Note offsets)
17748/P1340/004928 - Ross-Tech Wiki

 

[jjpark]

Looks like the motor was moving pretty excessively. You might have bad motor mounts because to me some of that sporadic rattle sounds like metal against metal on the left side. Especially at .45 seconds right before you moved the camera to the left side.

 

[tagraf]

I want to thank Tomvw for pointing out what may be the easiest case ever. But... it's not over. I feel hesitated to declare this as the root cause of all things because I did drop this off at a European shop. My question is... if it had existed the entire time, why didn't they find it earlier? In fact, they should have already found it. Either way, they never told me. Here's how I found it:

Boom. What in the world happened? This obviously goes to one of the intakes. If this breaks, this would explain why all cylinders were misfiring (right?).

What part is this? How do I replace it? I need to put it back together and see if it runs. If it does, then this Passat's a keeper!

 

[berg07]

Is the serpentine belt tensioner moving too much in the video? Is it supposed to move like that?

 

[tagraf]

Hey all, it looks like an air intake valve snapped off too. It says "Made in Germany", part number 02 07 02 (can't find it in Google) with a number 23. What part is this?

Serpentine belt is tight. When it misfires, engine would shake violently sometimes.

 

[Electron Man]

The vacuum hose in this photo

is part of the evaporative emissions system. You can use a 3-way Brass Barb T-fitting for 5/16" hose (like this) instead of sourcing the plastic tee (which will eventually crack again) from the dealership.

You can either use Norma clamps or the one-time use clamps as replacements.

To remove the broken off plastic piece from the rubber hose, use a 6mm allen wrench inside the hose as force against the broken tee you want to push out of the hose. That plastic is stout...attempting to remove the broken tee piece from the hose using pliers is futile.

The valve you mentioned, btw is a check valve. It's available from German Auto Parts.

 

[tagraf]

Excellent. Good idea. As a temporary measure, I've bypassed the check valve and plugged it so I can determine whether that's the actual issue.

To my unfortunate demise, the car now will not start, no crank, no clicking, no sound whatsoever. Really suffering here. I'm trying to figure out why it's not starting although I'm getting electricity.

 

[Tomvw]

NO CRANK.
1 Check fuse #14 and fuse #6. With ign on, use a meter or test light to check for 12V on both sides of both fuses.
2 Check relay #13, (and relay #12 if it exists). Connect a wire from pin 30 to pin 87 in the relay socket/s.
If it works with the relay/s jumpered, there is a fault in the relay or its control circuit.
3 Check Ign switch. ( should have 12V on term 50b with the key in start position)
( should have 12V on term 15 with the key in on position)
4 Check wiring from term 50b on ign switch through relay/s to term 50 on starter solenoid.
With the key in the start position, if there is 12V at term 50 on the solenoid, the starter or solenoid is faulty.
Note: With the key in start position, if there is more than 1V between the battery negative and the starter body,
there is a fault with one of the main ground cables.
5 Check from Ign Sw 50b through the relays coils, & switches to ground.

NOTE: Ignition switch terminals 50 & 50b are sometimes shown as connected together in the switch.

If your relays have these terminals 30 (12V from ign sw 50b*), 87 (12v output), 86 (12V from ign sw 50b*), 85 (ground via clutch/NP switch or alarm system).
If your relay is numbered differently, 30 and 87 are the N/O contacts, 86 and 85 are the coil connections.

* If there is a relay in position 12, this voltage is supplied from the ignition switch 50/50b through relay 12 to relay 13.
Note: Relay #12 is not a standard relay, it has electronic control.

This image might not be the same as yours, but it can be used as a guide.