After dismantling the intake on my '02 VW TDI Jetta I discovered that the intake manifold was completely coated with a thick tar-like goo. The intake was more than 75% restricted (and the car still ran great!!). What’s going on? I noticed an oily coating on the hoses going to and from the intercooler. Oil consumption was normal (ie. not much). Is it possible that the turbocharger bearings are shot and leaking oil into the exhaust which is then recirculated via the EGR system into the intake? Is this in any way normal? The car has 145k miles on it. Thanks!
The reason why these intakes plug up is because of the crankcase gasses that get introduced into them. And the only thing that can be done is clean the sludge out of the intake and reinstall it, and wait until it sludges up again.
I have a couple coworkers who own these VW TDI’s. And to prevent this sludging problem from reocurring, we designed up filter system that seperates the oil from the crankcase gasses so the oil drains back into the oil pan, but the crankcases gasses get burned. They’ve had them on their engines for little over a year, and so far, so good.
Common on the diesels. Cleaning can be a DIY job. Some cars get little or non, and some a lot. I get very little. There are a number of theories about this. Some say it is related to the way you drive (I drive just the way that the theory suggest causes it and I have have little or no build up.) Others blame it on fuel or this or that … I don’t think anyone really knows.
As to why it ran fine, easy, VW diesels have lots of excess air so while it would appear that the clogging should slow things down, it really is not.
For a lot more on this subject than anyone would want stop by www.tdiclub.com Good Luck