Engine - Intake Valve/Combustion Chamber Carbon Buildup
Group: 15Number: 96-02
Date: Mar. 11, 1996
Subject:
Pistons, Combustion Chambers, Intake Valves (Carbon Build Up)
Model(s):
All with (Engine Code AAH, AFC)
Condition
Carbon buildup on the top of pistons, in combustion chambers, and on intake valves, caused by using fuels that do not contain a sufficient blend of detergents can result in:
^ Lack of performance or poor idling.
^ Malfunction Indicator Lamp (MIL) on.
Service
If a vehicle exhibits the above symptoms and is accompanied by any of the following Diagnostic Trouble Codes (DTC's):
- Verify the Knock Sensor torque is correct 20 NM (15 ft Lb).
See Repair Manual Group 28 for Knock Sensor checking.
If Knock Sensors are operating correctly the engine combustion chamber will require a chemical decarbonization.
- Following instructions, 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 (Can.) to remove carbon deposits. It will also be necessary to change engine oil after carbon removal. (Oil filter not required).
Wynn's V.I.C. can be obtained through your local Wynn's Oil representative.
Caution!
Use of any other cleaning fluid could damage emissions components, use only Audi approved Wynn's V.I.C.
Carbon removal will be performed within the original vehicle warranty period as a one time no charge customer satisfaction action (When the condition described above exists)
^ Be sure to attach a copy of the 1551 print-out to the work order for future verification.
Note:
Customers should be made aware that carbon build-up is largely due to fuels that do not contain a sufficient blend of detergents. Customers should be given the brochure "Facts about Carbon and Fuel Quality" (Literature No. W42 552710 0)* and advised to use Autobahn Gasoline Additive (ZVP 239 003) which is very effective in reducing carbon buildup when used as directed.
When procedure applies to vehicles within warranty use the following:
Claim Type - W2
Damage Code: 1560 16000 1
Decarbonization/Oil change
Labor Operation: 1560 561 75 TU
Knock sensors diagnosis
Labor Operation: 2872 720 60 TU
If vehicle returns with the MIL on, and showing the same DTC's after performing the decarbonization, contact the Audi Dealer Technicians Helpline.
* You will soon receive an initial supply of this brochure, additional quantities can be ordered by calling.