Cam deviation from IMS?

Thinking about doing my variocam pads this winter or next. I called my indy shop to just see what they would quote me, I was curious. I told the service advisor my cam deviation numbers which are -8 on bank 1 and -4.5 on bank 2. He wanted to know all about the IMS, when it was done, what paperwork I have etc, and said they would need to drop the transmission and examine the IMS before taking on the job. His implication was the IMS install caused the cam deviation numbers. He quoted me 4 hours labor just doing diagnostics. I'm kind of spooked by this now. The IMS was done by the prior owner, maybe 4-5k miles ago. It's a roller bearing solution, I have photos of the PO's install but nothing else documented. You guys think inspecting the IMS is necessary? Car has 104k miles, the engine whines a little more than most at low revs and I'm pretty sure the whine is from the old variocam pads (I talked to the IMS vendor about that noise and he said definitely not IMS). It's a little rough at idle but no other issues and no engine codes.

Quotes source post: 19142269

I'm no Porsche mechanic but a couple years ago I did my own IMSB (roller bearing) replacement along with the bank 1 and IMS chain tensioners. About a year ago I did the bank 1 variocam pads and short chain. My deviations were -7 and -1, now they are -2 and -1 and stable*. I don't see how the IMSB could cause increased deviation unless it's badly worn, as in wobbly bad, but that would be obvious. Weak tensioners allow more chain slack increasing deviation so you could start there for a slight improvment. Bank 1 and the IMS tensioners are easy to do, bank 2 a little harder. Maybe ask for your indy's opinion. They've been superceded over the years too. Increasing deviation is cumulative wear: the chains (all five) and sprokets, chain guides (all seven) wear, and the tensioners weaken so at over 100k miles you've got your share of wear. * I will add that doing the above work only brought my bank 1 deviation down to about -4.x. I manually adjusted my sproket to get another -2.x degrees. Porsche didn't use hydraulic tensioners when they assembled the engine, they used a solid tool, so I compensated for this and other wear by advancing the sproket slightly.

You don't mention your year model but since you are talking about cam pads I assume you are talking about a 5 chain m96. On a 5 chain m96 the cam timing tool assures the Exhaust cam is properly timed but does NOT ensure the Intake cam is properly timed, and the Intake cam is where the deviation numbers come from.. For the Intake cam to be properly timed , the two small chains/gears have to be 7 pins apart ( on the dots on the gears) , the twp small chains cannot be worn, and the Intake cam timing pointer cannot be bent... So if you want perfect cam deviations I would suggest also replacing the two small chains while doing the cam pads.. For the IMS Bearing to have any effect on cam deviations it would have to be failing ( and would have metal in the oil filter or on a UOA ) .The wear on the two longs chain will be compensated for by the timing tool adjustment slots on the Exhaust cam gear..

Thanks. Yes, it's a 5 chain. I understand the shop's concern about the PO's IMSB work, but I really don't think it's contributing to the cam deviation on this car. No metal that I could see in the oil filter. If the cam deviation numbers were unstable, or if I had any other symptoms, I'd take it more seriously. Hearing that the shop wanted $600 in diagnostic fees before giving a quote was clarifying. I'm going to set this aside until next winter, or until I get a bank 1 code. My plan is to DIY it - drop the engine and do the four pads plus cam-to-cam chains.

Quotes source post: 19143005

As Skip said, it's highly unlikely the installation caused the deviation (unless they screwed something up royally, which in that case it probably wouldn't be running or running correctly). With the mileage the car has, the wear pads are done. It's hard to put a mileage on when they need to be replaced, but it's on average every 60k miles. I've seen them totally shot at 25k and perfect at 100k, so there are lots of variables. More than likely the shop who did the install had blinders on and just did the bearing OR the customer chose not to change out the wear pads. With one of the values at 8 degrees, it's needed the wear pads replaced now for quite some time. If the wear pads aren't the issues, then it could be chain stretch, cams were not timed properly or the sprocket slipped, or there is an issue with the IMS bearing or the IMS shaft itself. I'd also recommend dropping the oil pan at your next oil service to inspect for debris. You likely will find bits of the wear pads in there you should clear out.