Camshaft adjuster failure?

[mc_hotmail]

My 2007 A4 quattro died. Timing chain cover removed. At TDC and timing belt still on, camshaft locking tool can be installed with no interference. The 3 sealing rings (06F198107A) of the camshaft adjuster were all destroyed.

When I turn the crankshaft, around the time one pair of intake valves fully open, I can see the exhaust cam is moving but the timing chain and intake cam do not move. Then comes a popping sound (likely from the cam adjuster), and the timing chain and intake cam "catch up" in a quick snap. Is the camshaft adjuster gone?

Camshaft Adjuster 06F109088J

[Hr4rge35]

I'm not an expert on this, just went through my own adjuster replacement that turned into a cam replacement but fwiw I wonder if, since the adjuster is hydraulically activated and you of course don't have oil pressure that is standard behavior. Is the tensioner and everything else in?

[mc_hotmail]

Yes, the tensioner is there and will extend fully right before the pop. I installed the 3 sealing rings and the tensioner last year by removing the cam bearing cage (stripped adjuster bolt). At that time, I don't recall the popping and snapping movements, but I also might not have turned the crank like I do now.

Today, I found this video in which the guy opened up the cam adjuster: VW Audi Cam Adjuster (Phaser) Cleaning | MK6 Golf R

It shows the inside piece driven by the hydraulics. It's solid and doesn't seem to break easily. Since mines still can maintain both cam positions after the pop, it wouldn't be the broken pin scenario shown in this Iceman's photo (right side): https://www.audizine.com/forum/showt...1#post12948845

@Hr4rge35 You're most likely right. I feel better now -- just need the 3 sealing rings.

[mc_hotmail]

An update to close this thread -- The cams behavior and popping sound described above are normal. Once I install the 3 new rings, crank the car, ignoring those horrific popping sound for a few seconds, the engine starts and idle, the popping sound goes away.

[Charles.waite]

Well, the adjuster should be locked at 0º when there is no oil pressure. I can verify this as I have a spare adjuster in my basement. Theres a spring loaded pin that locks the two halves together at rest then when oil pressure is applied to the pin it is pushed out of the lock and the adjuster can rotate according to the N249 adjuster mapping.

So your adjuster bolted to the end of your cam is toast it would seem. and when you're cranking it, and theres no oil pressure the adjuster internals are slamming against each other. Probably not a recipe for reliability as those components aren't meant to be smashing into each other like that...