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Oil Sludge in the 1.8L Turbocharged Engine

Sludge is the thickening of engine oil. It’s caused by moisture, heat, and other contaminants that break the oil down, causing it to gel and reducing its flow and lubrication qualities.

Sludge in Audi’s 1.8L Turbocharged Engine

Certain 1997-2005 Audis have a 1.8-liter turbocharged engine with a tiny 3.7-quart oil capacity.

The turbochargers in these engines are hot and, according to some mechanics, there is simply not enough oil to properly dissipate the heat. The small oil capacity also removes any margin for error on oil changes, owners better not be late or they’ll pay the price.

Volkswagen did install “oil coolers” in some of these Audis, but owners say they didn’t do much other than leak.

An Extended Warranty

In 2004, VW extended the warranty on some cars to 8 years and unlimited mileage. They also offered to help compensate owners who’ve had oil problems and already paid for repairs. In order to be eligible for that help, however, you had to provide documentation showing “adequate maintenance records”.

Unfortunately, Audi has a different definition of “adequate.” Owners who threw out one oil receipt, missed an oil change by a few miles, or decided to save a few bucks and change their own oil were all known to have their claims denied.

The situation was bad. Even Len Hunt – who was then vice president of VW – said he thought the requirements for consumers to get reimbursed were too strict.

“When you’ve got a reputation for not such stellar quality, you’ve to treat the customer properly. Sometimes your rules and regulations and the culture of the company can be a little bit harsh when it gets translated down to the customer level,” he said. “We’ve got to have some latitude in there.”

Class-Action Settlement

VW and Audi were sued multiple times for their strict requirements, their unwillingness to help owners, and accused of committing fraud.

VW eventually eased the restrictions on sludge claims and reached a settlement agreement on their lawsuits. They denied any wrongdoing in the process.

Settlement Provisions

  • Owners will be compensated 100% of the repair costs if they can prove they performed the last two oil changes within the recommended specs before any oil sludge or engine failure started. There is a 20% “permissible variance” on those time and mileage limits.
  • Owners will receive 50% of the the repair costs if they cannot provide proof that the last two oil changes were made within the recommended specs before the oil sludge or engine failure happened.

There is additional information about Audi and Volkswagen oil sludge problems on

Where This Problem is Likely to Occur

Model Gen Years PainRank
A4 Gen 2 2001–2004 7.71

What Owners Are Saying

“This car is a NIGHTMARE. I own the A4 1.8T Quattro and it has been one problem after another. Unbeknownst to me, my entire engine was replaced in 2003 and due to the oil sludge issue (Audi issued a recall for this problem) I am having several other engine problems.”

2002 A4 owner in Atlanta, GA

“I May, 2008, the oil light came on, we had a qualified mechanic check the vehicle thoroughly and no problems were found. 2 days later, the engine completely shut down and the vehicle has been inoperable since that time.”

2003 A4 owner in Columbus, OH

“The engine oil light illuminated while driving. The engine was inspected, and it was discovered that there was heavy oil sludge. The oil pump had to be replaced. The car had only 26,000 miles at the time of the repair.”

2003 A4 owner in Nashville, TN

Story Timeline

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OK, Now What?

Maybe you've experienced this problem. Maybe you're concerned you will soon. Whatever the reason, you can help make sure it gets the attention it deserves.

  1. File Your Complaint is a free site dedicated to uncovering problem trends and informing owners about potential issues with their cars. Major class action law firms use this data when researching cases.

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  2. Notify CAS

    The Center for Auto Safety (CAS) is a pro-consumer organization that researches auto safety issues & often compels the US government to do the right thing through lobbying & lawsuits.

    Notify the CAS

  3. Report a Safety Concern

    The National Highway Traffic Safety Administration (NHTSA) is the US agency with the authority to conduct vehicle defect investigations & force recalls. Their focus is on safety-related issues.

    Report to NHTSA

  4. Contact Audi

    Audi Support

    2200 Ferdinand Porsche Drive Herndon VA 20171 USA

    More info for international customers

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