Service
Perform the following:- Connect VAG 1551 or VAS 5051 scan tool.
- Select Address word 01 "Engine Electronics".
- Select Function 08 "Read measuring value block".
- Read and print measuring value blocks 4, 6, 32, 55 and 60.
- Check for Diagnostic Trouble Codes (DTCs) stored in DTC memory.
- Print any stored DTCs.
- Take corrective action for any stored DTC according to the DTC table in the OBD II Fuel Injection & Ignition section of the 2.8 Liter V6 5V Repair Manual.
Note:
In most cases no DTCs will be found.
- Check for correct fuel level (vehicle must not be out of fuel).
After vehicle sits for a minimum of several hours (preferably overnight):
- With ignition switched ON.
- Check engine coolant temperature sensor for reasonable values in measuring value block 4 (must read approx. ambient temperature).
- Check throttle body for proper mechanical function.
- Must operate smoothly between closed and wide open throttle.
- Crank engine while observing throttle angle specifications in measuring value block 60.
- Throttle angle must be greater than 60.
- Check and record fuel pressure.
- If coolant temperature sensor, throttle body and fuel pressure are OK:
- Remove all spark plugs and perform a compression test and cylinder leakage test on all cylinders (record results).
Note:
Low compression may indicate carbon particles are present on the intake and/or exhaust valves and in the combustion chamber (causing the valves not to seat properly)
If compression and leak check are OK:
- Contact the Dealer Technician's Helpline.
If compression and leak check are not OK:
- Install old spark plugs.
To help prevent any future carbon deposit buildup:
- Install new engine coolant thermostat Part No: 078 121113 G using new 0-ring Part No: N901 368 02.
- Temperature gauge will read slightly higher due to thermostat operating temperature increase from 87° C to 92° C.
- Depress throttle fully and crank engine until engine starts then switch ignition OFF.
- Following instructions in the kit, use Decarb Tool Kit US 9025 along with Wynn's(R) X-Tend(R) V.I.C. Combustion Chamber Cleaner: Part No: 61510 (U.S.), Part No: 61512 (Canada) to remove carbon deposits.
- It will also be necessary to change engine oil after carbon removal. (Oil filter not required).
Wynn's(R) V.I.C. can be obtained through your local Wynn's(R) Oil representative. For your local Wynn's Oil representative call 1-800-98X-TEND.
Caution!
Use of any other cleaning fluid could damage emissions components, use only Volkswagen approved Wynn's V.I.C.
- Make sure to attach a copy of the 1551 print-out to the work order for future verification.
Note:
Customers should be made aware that this type of carbon build-up may be due to fuels that do not contain a sufficient blend of detergents. Customers should be advised to use Autobahn Gasoline Additive (ZVW239 003) which is very effective in reducing and preventing carbon buildup even if the fuel used does not contact a sufficient blend of detergents.
- Remove spark plugs.
- Disconnect injector wiring and crank engine for minimum of 30 seconds.
- Reconnect injector wiring.
To help prevent any future carbon deposit buildup:
- Install new spark plugs Part No: 101 000 067 M (NGK BKR6EQUPA).
Note:
Perform the following only with a fully charged battery
- Start engine (if necessary depress throttle fully and crank engine until engine starts). Continue to run engine until warm.
With engine fully warmed:
- Road test vehicle under load with engine between 4000 to 6000 RPM's for approx. 10 miles (use appropriate lower gear to stay within legal speed limits).
Procedure is complete.
When procedure applies to vehicles with-in the New Vehicle Limited Warranty, use the illustration above.