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rob's garage

Rob MacGregorLAURA LEYSHON

Hi Rob,

I bought a used Audi 2001 A4 1.8 turbo and afterwards found black engine goop inside the oil filler cap. I did some research and found that Audi took responsibility, recognized this problem and extended the engine warranty by factory for eight years - unfortunately now expired.

To open up the engine and check heads is very expensive for a car with 168,000 kms on the clock that is only worth $9,000. What to do? Should I worry since I do want to keep it and pass down to kids?

Thanks in advance.

Steve

Well Steve, a couple of things are in play here.

You have a chronic and terminal case on your hands.

If you pass this car on to your kids ? Well, nothing says love like being given a hole in the driveway that you pour money into.

Sorry if that sounded cruel Steve, but I'm afraid that's what going to happen.

It would be easy for me to start on a Turbo Audi rant but they are not alone in their "Black Death" misery. This was a term that was sometimes used in the 80s to describe the black molasses found inside engines. This is not to be confused with the old standby "you got carbon on the valves!" which was made famous by Walter Matthau in the movie A New Leaf. For all you car buffs, there are some hilarious car scenes in this movie. Pull up a You Tube search for it - the opening scene is a hoot.

To be fair and I know it's no consolation to you Steve, but the list of new vehicles afflicted with this terminal disease is fairly long.

  • Audi - 1997-2004
  • Chrysler - 1998-2002
  • Dodge - 1998-2002
  • Hyundai - 1998-2004
  • Lexus - 1997-2003
  • Toyota - 1997-2003
  • SAAB - 1999-2003
  • Volkswagen - 1997-2004

This list is not exhaustive as not all engines made by these manufacturers are sludge-prone. Much of the time the problems are caused by turbo charging - more accurately, the heat caused by turbo charging. That said, if the engine support systems, such as the cooling system, crankcase ventilation (PCV) and the overall mechanical condition of the engine are not up to snuff, there are no guarantees that the engine will hold up over time.

The cooling system needs to be in perfect order especially on a turbo engine. Unfortunately buying a used car can't always guarantee this to be true. It's also necessary to use very high quality synthetic oil that has a very low sulphated ash content. With extreme heat, these particles can be forced to congeal and start the formation of sludge. New engine designs coupled with low hood profiles for aerodynamics, have caused engineers to develop low capacity oil pans. Oils do four things; they lubricate, seal, clean, AND COOL. If an engine design does not allow for much more than five litres in the crankcase, an option may be to install a larger than normal oil filter. Although it's not much, every little bit of extra oil you put inside the engine will help. And finally, the PCV system must be clear of carbon and sludge build-up. It is vital that the crankcase fumes are purged out of the internal cavity of the engine as these fumes carry corrosive particulates that also contribute to the formation of the sludge.

Steve, in short, heat is the enemy and you need to take as many precautions as possible to mitigate temperature increases under the hood. I can't help your overhaul process, nor what your children will think of you after you have given them this car, but I can suggest the installation of an external oil cooler on top of the points I have already outlined.

Good luck Steve.

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