Engine Performance - Fuel Quality and Carbon Deposits

88audi06

Applies To: ALL VEHICLES WITH GASOLINE ENGINE ALL MODEL YEARS

Subject: Fuel Quality and Carbon Deposits

Number: 15 Group: 88-01

June 9, 1988

Engine

Research by Audi and other manufacturers has shown that the performance of gasoline engines today is directly related to the type and quality of fuel used.

Fuel without the proper additives can cause carbon deposits to collect on fuel injectors and intake valves.

The build-up of carbon deposits can cause the following conditions:

^ unstable idle ^ power loss
^ surging ^ engine run-on
^ misfiring ^ pinging/knocking

The extent of the carbon build-up varies depending on the type of fuel used, operating condition. etc. Refer to current service literature for further description of !he deposit grading system.

Moderate/heavy deposits (grades 4-10) can only be removed by cleaning or replacing the injectors and by using the "Kent-Moore Carbon Blaster" to clean intake valves.

Light deposits (grades 1-3) on intake valves can be removed as follows:

^ check that fuel and ignition systems are adjusted to specifications.
^ add one 20 oz. bottle of "Autobahn Gasoline Additive", P/N: ZVW 246 001 to fuel tank

Note

Fill fuel tank completely. Do not refill fuel tank until the fuel gauge reads 1/4 full.

CAUTION

Do not exceed the following recommendation:
Oil change Maximum treatments
interval between oil changes
5000 miles 2
7500 miles 4


Prevention

Prevent carbon build-up through the use of gasolines containing the proper deposit control additives. Suppliers such as Shell, Chevron and Amoco sell gasolines containing these additives. Other suppliers may be located in certain areas. Canadian owners should consult with their local service stations or oil company about available gasolines with additives.

In areas where gasoline containing deposit control additives is unavailable, carbon build-up can be controlled as follows:

^ add one 6.5 oz. bottle of "Autobahn Gasoline Additive", P/N: ZVW 246 003 to fuel tank before every fill up

Note

Fill fuel tank completely, Do not refill fuel tank until the fuel gauge reads 1/4 full.


CAUTION

Part numbers are for reference only. Always check with your Parts Department for latest information.