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Car in question: 1999 C4, M96.02, 41k miles (had it since 20k miles), original/stock IMS bearing
Alright, so I stumbled on some posts regarding durametric readouts for camshaft deviation to check into the health of the IMS. I remembered I logged a bunch of real-time parameters back in 2012 just to establish a baseline with my new Durametric tool at the time. I finally found my old hard drive with the data and to my surprise, my camshaft position 1 deviation read -8.97 cold at idle and varied down to -9.53 when driving around. Camshaft deviation, position 2 is solidly at -3.19 regardless of engine speed. On another post, I read that the durametric software may have had issues logging this parameter at the time.
No CELs, no logged errors, been running fine for the last three years, and yes, I drive the snot out of it. When I cut the oil filter I find the random tiny shards brown plastic from the variocam guides. I have a magnetic drain plug and have only seen a light amount of the typical fine metal on it. The previous owner kept meticulous records of all work done at the dealer, and no major engine work was ever done other than oil changes. I found a post about a potentially bent sensor plate on the cam where the engine is correctly timed but the sensor is reading the parameter incorrectly??
My thought at the moment is to not drive the car, pop the green plugs and check timing as well as pulling the sump pan for inspection. I also plan to log the camshaft deviations this week with the newer version of the software and see what I get. Assuming I get the same numbers, I have some questions:
1. Since the position 1 is moving around a little bit between running and idle (~0.78 degrees), should I start having my heart attack now?
2. If the timing is off by this amount, is it a simple re-timing of bank 1 if all else looks OK?
3. Dumb question also is how much timing adjustment can be made since the sprocket appears to have large slots for adjustment?
4. Another dumb question is if bank 1 skipped a tooth, would I know it already?
5. Should I just open up the bank 1 valve cover to inspect/replace the variocam pads? (trying to do the least invasive first)
6. Anything else to check/do?
Thanks for reading.