Engine - Poor Performance in Extreme Cold
Group: 20Number: 01-01
Date: NOV. 13, 2001
Subject:
Diesel Fuel, Cold Weather Conditioning for Driving at Temperatures Below 0°C (32°F)
Model(s):
New Golf, New Jetta with 1.9L TDI 1999-->2001
New Beetle with 1.9L TDI 1998-->2001
Supersedes T.B. Group 20 Number 00 - 03 dated Dec. 8, 2000
Condition
Poor diesel engine performance in ambient air temperatures below freezing 0°C (32°F) can be caused by a condition known as diesel fuel clouding (gelling/waxing), a result of improperly winterized/conditioned diesel fuel provided by fuel suppliers.
Water contamination in diesel fuel can also cause similar conditions as the result of ice accumulation in the vehicle's fuel system.
Service
To prevent the possibility of this condition occurring, recommend to diesel powered vehicle owners that a quality diesel fuel winterizer/conditioner be used during winter months. Volkswagen of America, Inc. recommends using Stanadyne(TM) One Shot Performance Formula All Season Diesel Fuel Conditioner in the correct amount per tank full of fuel as listed below.
CAUTION!
DO NOT use diesel fuel additives containing alcohol! Alcohol WILL NOT address fuel clouding (gelling/waxing) conditions. Using alcohol will damage the diesel injection pump.
CAUTION!
Part numbers are for reference only. Always check with your Parts Dept. for the latest parts information.
- Add 8 oz. (235 ml) per 15 gallons (60 ltr) of diesel fuel of Stanadyne(TM) One Shot Performance Formula All Season Diesel Fuel Conditioner directly to fuel the tank. Part No: ZVW 340 002.
Note:
For vehicles which will be operated at temperatures below -30°C (-22°F) add 12 oz. (355 ml) per 15 gallons (60 ltr) of diesel fuel.
To determine if condition is due to diesel fuel clouding (fuel gelling/waxing) or water (ice! moisture) contamination in the fuel system (tank, lines, fuel filter) use the following steps:
Diesel fuel system, inspecting condition
- Check fuel system for small air leaks i.e. air bubbles in:
^ Fuel filter (insertion hole of regulator valve out of round)
^ Fuel lines
- Repair or replace as necessary.
Diesel fuel, inspecting condition
WARNING!
When working on ANY fuel system, ALWAYS read and follow Repair Manual CAUTIONS and WARNINGS!
- Remove fuel gauge sensor/fuel reservoir assembly from fuel tank (see appropriate Repair Manual Group 20 Fuel tank and components, removing and installing).
- Observe fuel condition for contamination or clouding.
Fuel with water contamination:
If fuel is contaminated with water (ice/moisture):
- Drain fuel system (tank lines).
- Replace fuel filter.
- Add (8 oz. (235 ml) per 15 gallons (60 ltr) of diesel fuel) of Stanadyne(TM)/One Shot Performance Formula All Season Diesel Fuel Conditioner directly to fuel tank Part No: ZVW 340 002.
- Close fuel system, reinstall fuel gauge sensor/fuel reservoir assembly.
- Add new clean diesel fuel from a known winterized source.
Note:
Fuel contamination which includes water accumulation is not covered by Warranty
DO NOT install Part No: 1J0 919 183H (fuel gauge sensor/fuel reservoir assembly) for fuel contamination.
Fuel, clouding:
If fuel is clouding (gelling/waxing):
- Close fuel system reinstall fuel gauge sensor/fuel reservoir assembly.
- Allow vehicle to sit indoors long enough to bring fuel temperature up to approx. 13°C (55°F) (may take several hours).
- Remove fuel gauge sensor/fuel reservoir assembly again and observe fuel condition again.
^ Cloudiness (gelling/waxing) should no longer be seen.
- Add the correct amount (8 oz. (235 ml) per 15 gallons (60 ltr) of diesel fuel) of Stanadyne(TM) One Shot Performance Formula All Season Diesel Fuel Conditioner directly to fuel tank.
Note:
For vehicles which will be operated at temperatures below -30°C (-22°F) add 12 oz. (355 ml) per 15 gallons (60 ltr) of diesel fuel.
- Thoroughly mix the additive with the fuel. To enhance fuel flow and engine performance during cold weather:
- Install Part No: 1J0 919 183H (fuel gauge sensor/fuel reservoir assembly).
Fuel gauge sensor/fuel reservoir assembly, installing
- When installing fuel gauge sensor/fuel reservoir assembly (see appropriate Repair Manual Group 20 Fuel tank and components, removing and installing).
Fuel gauge sensor/fuel reservoir assembly, installed position
- Mark on sensor must align with mark on fuel tank (arrows).
^ Return line -1-, blue or with blue markings must be attached to connector marked R".
- Install fuel supply line -2-.
Note:
After installing fuel gauge sensor/fuel reservoir assembly ensure that supply line -2- and return line -1 - (marked R) are securely clipped into fuel tank.
Additive, ensuring distribution throughout fuel system
- Start and run engine approx. 10 minutes to ensure conditioned fuel has circulated throughout the system.
Warranty
Fuel contamination which includes water accumulation is not covered by Warranty.
- Review with customer the necessity of obtaining fuel from a known winterized source during colder weather.
When performing fuel clouding diagnosis and installing a new fuel gauge sensor/fuel reservoir assembly in vehicles within the New Vehicle Limited Warranty. use the table as shown.