P0017 code and Knocking. Need help with next steps.

[jasonmesq]

Hey guys,
I'm new to ownership and new to the forum, but have already used the forum to exhaust my attempts to fix my issue and need some help to proceed.

Vehicle: 2008 Saab 97-x 4.2l Vortec. 190,000 miles.
History: Purchased the vehicle a few weeks ago for my girlfriend to drive after her Jeep killed its engine. Nicely maintained, recent full tuneup. Ran and drove great, with no unusual noises or malfunctions. I drove it for about a week, about 100 miles with no issue. Then, check engine light came on and it ran poorly and even died on me while driving a couple of times. Pulled the OBD code at is P0017 Crank/Cam Position Correlation - Bank 1 Sensor B. Then, it started knocking. Not a "tick" but a true knock which sounds like it is coming from top-end near oil filler, and knock increases with rpm.

Attempted resolution:
1. Inspected all wiring and connectors to sensors, cleaned connections and grounds, installed new battery. All wiring looked very good, no corrosion or oil contamination. No change.
2. Replaced Cam Position Sensor (CamPS). No change.
3. Changed oil and replaced Variable Valve Timing Solenoid (VVT). No change. (Oil that I removed was actually very new from tuneup.)
4. Replaced Crankshaft Position Sensor (CrankPS). No change.
5. Pulled off the serpentine belt and ran engine to confirm the knocking was not from an accessory. It wasn't. Knocking definitely seems to come from up top.

If I disconnect the battery or clear the code with my reader, once I start it and let it idle to temp, the code will come back after about ten minutes. I've not done any other "clearing" or "reset", because I'm not sure what may be needed.

So now I need your help for next steps to take.
1. Before I start pulling the valve cover off to look around, I'd like to test the electric signal at the plugs to each of the above-mentioned sensors and VVT. Can any of you tell me the readings I should get at each sensor plug while the car is running? I think on the CamPS and CrankPS there should be 12 volts at two of the wires, and the third wire sends the signal back to the ECU. But I don't know which wire is which to test.

2. The knocking sound is significant, and I'm wondering if it is the Cam reluctor/actuator. But I'm curious why that would just "suddenly" happen when the check engine light came on. Again, the vehicle ran great for a week.

Any tips and advice would be greatly appreciated to keep this safely on the road.

A bit of background on myself. I've worked on my own cars and others for over 30 years. I have significant mechanical and electrical experience. I currently own and drive seven vehicles (not included this one) but the only GM product I currently have is a 1953 Chevy pickup.....the easiest car in the world to work on!

Thanks, Jason

 

[Mooseman]

Sounds like something is up with the timing chain system, which would explain the code. That code is possible if the chain jumped a tooth somewhere or the chain tensioning system has an issue allowing too much slack. Could be the tensioner itself or the guides that broke, which has happened in the past. Check for aluminum bits or glitter in the oil. You could try removing the two plugs that cover the bolts for the chain guides and looking inside with a mirror or boroscope. Beyond that, The valve cover has to some off. If it is the guides or tensioner, you're looking at a world of hurt to replace these parts.

How to replace I6 timing chain and tensioner

 

[rchalmers3]

Sounds like something is up with the timing chain system, which would explain the code. That code is possible if the chain jumped a tooth somewhere or the chain tensioning system has an issue allowing too much slack. Could be the tensioner itself or the guides that broke, which has happened in the past.

@Mooseman, if the timing chain tension has become so loose that it causes poor running, stalling and knock, could it also have slipped time, thus creating valve/piston interference?

Or do you think the engine knock is simply chain slack? Your experience on this subject is appreciated.

Rick

 

[Mooseman]

@Mooseman, if the timing chain tension has become so loose that it causes poor running, stalling and knock, could it also have slipped time, thus creating valve/piston interference?

If it just jumped a tooth, Interference may not happen but would be out of time and cause compression and timing issues. Or it might not have jumped but the chain is so slack it's out of time.

Or do you think the engine knock is simply chain slack?

Could be both.

 

[mrrsm]

Just to Clarify for Post #5... The GMT360 GM 4.2L LL8 I-6 Engines do NOT use a Cog Style Timing Belt to control the Camshaft to Crankshaft interplay. They rely upon a single leaf Bicycle Type Linked Chain for this purpose.
[Mod edit: The post prior to this one referred has been deleted and poster banned as a spammer]

OP... Shooting a 360 Degrees Video of the Top, Front. Left Upper & Lower and Right Upper & Lower with paused, staged "Glamor Shots" would give us a much better idea of what is actually happening with the engine at idle.

This is another "On Topic" P0017 Code Thread which may prove helpful:

SOLVED! - P0017 Assistance

As stated in my thread; "I Must Be Crazy" -- I own a 2005 GMC Envoy XL; I want to believe my trim level is the SLE. It has all kinds of bells and whistles. LOL. 4.2L I6, 4X4, 185,000 miles. But I am to the point of pulling what hair I have left out. My post may need to re-directed as I am...

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