VW breathing

Dec. 1, 2013

This TSB applies to all 2008-2013 VW models equipped with the 2.0L engine. The engine may exhibit rough running, engine noise or MIL on with DTCs P0300 (random/multiple cylinder misfire), P0301, P0302, P0303, P0304 (per cylinder misfires), P2279 (intake air system leak), P1297 (charger throttle connection / drop in pressure), P1093 (Bank 1 fuel measuring system 2 malfunction) or P2187 (system too lean at idle, Bank 1) stored in the ECM.

A faulty PCV valve will allow pressurized intake air back into the valve cover/crankcase. This pressurized air can blow out of several openings. The oil filler cap, air filter and dipstick should first be checked for evidence of oil blow out.

-          With the engine off, remove the engine cover and locate the hose connecting the intake manifold to the crankcase. Disconnect the hose from the intake manifold side and clean off any residue with a cloth. Blow into the hose. If there is some air resistance, then the check valve is operating correctly. If there is no resistance, then the PCV valve should be replaced.

-          With the engine running, disconnect the hose from the valve cover. Plug the hose and check idle quality. If the idle quality improves, replace the PCV valve.

-          With the engine running, remove the dipstick. If the idle quality improves, replace the PCV valve.

-          Remove the oil fill cap. Place a stiff piece of paper over the fill cap opening. The paper should be sucked against the hole within a couple of seconds if the PCV valve is operating properly.


The best measurable way to ensure the functionality of the system is to view fuel trim readings in MVB32. If faults pertaining to this part are found, do not erase the faults. Proceed with the steps as outlined in this bulletin, prior to following the GFF test plan to avoid erasing fuel trim readings.

  1. Using VAS tester to read current fuel trim level in MVB 32 field 1 (idle fuel trim) and field 2 (part throttle). Nominal values are 0 +/- 3 in both fields.
  2. Replace the original valve with a “test” part. A know good test part should be kept for further cases.
  3. Make sure that no additional loads such as A/C and heated seats are turned on during the test.
  4. If the noise goes away or the engine is no longer running rough, valve replacement is recommended.
  5. Using the VAS tester, run basic settings 32 for at least five minutes.
  6. While running basic settings 32 for five minutes, fields 1 and 2 for fuel trim readings can be monitored.
  7. If fuel trim values improve and move closer to 0, valve replacement is recommended.
  8. If values do not improve, re-install the original part. Use of GFF is permitted at this point.