Volkswagen has, in my opinion, the worst possible customer service out of any company I have worked with. Their negligence in manufacturing a defective product (1998-2004 Passat 1.8/2.0 liter engine) and not outright recalling it is inexcusable and a complete safety hazard. I personally own/owned a 2001 Passat station wagon with the 1.8L turbo engine. The term Coking is what I am referring to but Volkswagen has been coining the term Oil Sludge in an attempt to erase liability on their end. Yes they did the 'service' of extending the warranty to eight years from the date of purchase, but what happens when the warranty runs out. You are, at that point, stuck with a defective product, which should have been recalled from the beginning, and spending an exorbitant amount of money to fix it. I have been back and forth between the dealership and the, lack thereof, 'Customer Care' line for weeks with NOTHING done to resolve the issue. Volkswagen knows what the problem is, knows they made a major mistake, and knowingly turned their back on customers. I continue to be treated with less than adequate service and feel compelled to tell everyone how unreliable their product and customer care line is. Volkswagen continues to show they do not believe in their product and the recent happenings with the 2008-2009 models equipped with DSG reconfirms my complaint.

I have a 2001.5 Pasaat GLS Wagon. I recently "de-sludged" the engine myself per VWs Technical Bulletin. I found no evidence of oil sludge in my engine. I did however find a considerable amount of oil coking. There was coked oil crystals (looks coffee grounds with almost diamond like hardness) throughout the crankcase vent system. Vent passages were fully plugged at the oil filer base and at the valve cover vent outlet.

The sump pick-up screen was also plugged with coked oil crystals. This is the source of the oil pressure light.

Oil sludge is dirt and contaminants mixed with moisture in the oil that forms a gelatinous type substance. Coked oil is residue that develops when oil encounters high temperatures. All oil will coke if subjected to enough heat.

Oil sludge is primarily due to poor maintenance practices- improper oil changes versus vehicle usage (short trips without getting the engine to full temp to burn off the water). Oil coking is primarily due to an error made at the design phase when calculating the heat rejection requirements.

I spoke with the Service Manager regarding this issue. He advised VW has had little problem with the 1.8T in other application - smaller cars. Basically VW has put a relatively small turbocharged engine at a high BHP output into a fairly large car without increasing the oil capacity. It is basic physics with work and heat. The result the oil cokes.

Shame on VW for blaming this latent design defect on the customer for poor maintenance practices. They require the customer to provide all oil change receipts to verify oil changes since new. Very few folks keep these records and VW darned well knew it when they initiated this policy. They are clearly mitigating liability.

I do my own maintenance and keep a log book on everything. Our car has had oil changes every 5000 miles religiously. I buy oil in bulk and do not keep receipts. Needless to say VW will not even cover the parts for me. I have ~$2000 in this. - oil pump. both turbo lines, all crankcase vent lines and hoses, gaskets, etc.

VW has introduced a larger oil filter to try and get the oil capacity increased. They have now changed the oil spec twice.

I fully realize design problems are made and have been involved with a few myself. It is not so much the errors that are made but how a company stands behind their product that matters.

Even with this problem I would have looked at VW again had they stood up and did what is right. What bothers me more than anything is VW's misrepresentation of the truth and then gaming the warranty. Not now, not ever will I look at VW again.

Bottom line the root cause from the evidence I have seen is insufficient oil capacity and oil cooling to absorb the heat in this application.

Based on all the problems we have had with this car it is painfully obvious VW is so far from 6-Sigma, from design, maintainability (god awful), all the way to after market support, it is not funny.

As an aside the Service Manager advised I get rid of the car stating it will coke again. He was amazed we got 155k out of it. He stated he has not seen one go this long. He also stated they will coke even with synthetic oil - pretty much confirms the latent design defect...

Due to him being straight up I very likely will go back to the dealership and look at another make of car they carry. Did I say never ever again VW?