Oldskhl

I have a 2004 D3 BFM 174k miles (41k by me), Bentley and VCDS free. No special tools, just std shop tools.

Timing belt, water pump, tensioner, thermostat replaced ~9k miles prior. Replaced ignition coils and plugs ~12k ago

Sitting at a long light I feel a blip like a misfire and a few seconds later engine starts smoking--could be fan wasn't running?. Kill the ignition since I am sitting at light and then start a minute later to pull into the gas station lot. Car studders a bit and making noise while driving. Kill the engine let sit and start back up after a few. Sounds quieter. Toe it to VW Technology in Marietta where Orlando diagnoses as cam tensioner (driver side). When the car is started at idle engine sounds fine, no OBD2 codes. Apply gas and nasty noise.

This leads me to a few questions.
1. What are the chances that I escaped with just tensioner/pad damage?
2. What are my chances I can fix this without pulling the timing belt, etc.

I see threads about just pulling the valve cover but need to make sure it makes sense in this scenario. Really $750 and two days labor is high end I want to spend. Otherwise I might as well part out and buy a new ride.

The car body is a bit rough so I don't want to drop a ton of money or time into it, but I also have money invested. New tires, compressor, struts etc.

Oldskhl

Forgot to add, this all occurred on the way to the shop to replace a headlight assembly (low and aim not working) and to find intermittent coolant leak.

Junius

When I had to replace my camshaft tensioner (passenger side) over a year ago, the symptoms were a nasty chain rattle noise at hot idle, slight rattle at startup, decreased and sluggish performance, and cam timing codes. All you have to do is to replace the cam tensioner and chain. While the original tensioner is about $800 per side just for the part, I purchased an aftermarket one on ECStuning.com for $350 plus $30 or so dollars for the chain. But I do believe the timing belt has to come off in order to do the job. You might as well do valve cover gaskets and spark plugs as well since the valve cover has to come off. I believe I did find a piece of the tensioner in the oil pan, so I had my mechanic clean the oil pan and oil pump filter out. It's been a year since I repaired mine and the car has been great. I put over 16,000 miles on this tensioner and its holding up quite well. No noise or rattle.

Oldskhl

Junius I read your prior posts. I will be ok buying Chinese parts on eBay-- tensioner and chain are under $200. My understanding is that if you have to pull the chain due to damage you have to pull the front bumper and redo timing. I am wondering what relation the car overheating is to this failure. It was smoking and the valve covers are bubbled pretty bad. Car was under 'low' for coolant due to intermittent leak. I am afraid I have more problems.

richard-tx

Cheap Chinese aftermarket parts don't last. I would only use them on a car I was going to immediately sell. There was a fellow that bought Chinese aftermarket upper control arms. The arms folded the first time he did a panic stop.

Oldskhl

I don't see any aftermarket that is not Chinese made and my $50 front axle has been fine for 28k miles. 1k in parts doesn't make sense for me. If I can get another 20k miles on the car I'd be happy.

Junius

Yeah I wouldn't use any Chinese parts when it comes to things like chain tensioners. Especially from EBay. It's quite a big job and you really don't want to redo that job over again. Like I said, I ordered mine from ecsTuning, which is a reliable source. As far as the coolant loss goes, you probably want to check the waterpump (since you've recently done the timing belt job), the coolant resorvoir, or most commonly, the oil cooler (located on the front passenger side above the alternator and very common place to leak coolant for 04-06 A8s).

Oldskhl

It's most likely oil cooler as coolant is ending up near passenger wheel, reservoir was replaced already. Let me see what the parts are for that. Thanks.

Junius

Yeah replacing the oil cooler is a heck of a job. It requires removing the exhaust manifold to get the bolt out. According to the book, "the engine must be removed".

Oldskhl

Ordered the parts to replace tensioner and chain on driver side and pad on right. Assuming I can get it back together and running properly with Bentley manual --I have to attack the oil cooler leak. Hopefully the head gaskets aren't toast from the engine overheating.


Do-able in two days? I have never tackled mechanical on engine before--tons of suspension work though and got all the tools ready