I had my '18 L494 in to the friendly local dealership twice in the past 2mo, and both times I reported a handful of issues, each time including a report of a DTC related to crankshaft position sensor DTCs as well as audible engine knock.
The first visit (late July), my starter motor was deemed faulty and was replaced; the crankshaft position sensor error(s) were deemed related to that issue (a causal relationship here is not clear to me), and the DTC apparently didn't resurface, so I took the vehicle back and carried on.
The second visit, in late August, was mainly scheduled since I pulled codes for the first time since getting the vehicle back about 3 weeks afterwards, and saw a crankshaft position sensor error with "Current Fault" designation. I scheduled another service visit and was informed that the DTC was in the "previous fault memory" and so would not be investigated. The software was updated on the vehicle (relating to my other concerns) and I let the dealership's service department know that I'd keep an ear out in case the engine knock got worse.
This past Friday, after some tooling around on some desert roads, I could tell the knock was a bit more pronounced, and the idle a bit rougher. After getting back to pavement and airing up, I saw my CEL now on (solid, amber), and saw no other messages (even when checking the "Check Messages" option in the gauge menu option, it read "OK"). Strangely, despite the lack of any additional message, I noticed as soon as I pulled away from airing up that I was in limp mode (aka "reduced power output" mode).
I made the <10mi trip back to the hotel in limp mode; the exhaust had some new gurgles and pops that I'd imagine sound somewhat like those on the SVR. I grabbed my code scanner from my room, headed back to the truck, and saw:
Pending Faults:
- P000A
- P000B
- P0024
- P0087
Historic Fault:
- P0021
I also took a video to capture the motor sound at idle:
The vehicle was dropped off at the nearest dealership Saturday morning (1 Sept), and at COB today (4 Sept) I'm still awaiting status on what parts will have to be ordered. I drove it 6mi there under its own power after confirming w/ the service department that a solid amber CEL and limp mode meant I could still make the short trip.
I'm genuinely hoping that serious engine work won't be necessary on a truck that's barely past 3mo old with about 6k mi on the clock. I guess the best case scenario is a new crankshaft position sensor, maybe a new timing chain tensioner (read about this plaguing generations past), and I'd guess a leak-down test for good measure to be reasonably sure the internals check out.
Worst case? Who knows.
To further complicate matters, I'm stuck out-of-town in a hotel I'd planned to check out of this past Saturday; luckily, I can work from here. Somehow I have a sneaking suspicion though that the Roadside Assistance benefit involving "reasonable reimbursement of out-of-pocket expenses if a warranty-related disablement occurs more than 50 miles from home" won't be as clear-cut as the verbiage makes it seem.
The first visit (late July), my starter motor was deemed faulty and was replaced; the crankshaft position sensor error(s) were deemed related to that issue (a causal relationship here is not clear to me), and the DTC apparently didn't resurface, so I took the vehicle back and carried on.
The second visit, in late August, was mainly scheduled since I pulled codes for the first time since getting the vehicle back about 3 weeks afterwards, and saw a crankshaft position sensor error with "Current Fault" designation. I scheduled another service visit and was informed that the DTC was in the "previous fault memory" and so would not be investigated. The software was updated on the vehicle (relating to my other concerns) and I let the dealership's service department know that I'd keep an ear out in case the engine knock got worse.
This past Friday, after some tooling around on some desert roads, I could tell the knock was a bit more pronounced, and the idle a bit rougher. After getting back to pavement and airing up, I saw my CEL now on (solid, amber), and saw no other messages (even when checking the "Check Messages" option in the gauge menu option, it read "OK"). Strangely, despite the lack of any additional message, I noticed as soon as I pulled away from airing up that I was in limp mode (aka "reduced power output" mode).
I made the <10mi trip back to the hotel in limp mode; the exhaust had some new gurgles and pops that I'd imagine sound somewhat like those on the SVR. I grabbed my code scanner from my room, headed back to the truck, and saw:
Pending Faults:
- P000A
- P000B
- P0024
- P0087
Historic Fault:
- P0021
I also took a video to capture the motor sound at idle:
The vehicle was dropped off at the nearest dealership Saturday morning (1 Sept), and at COB today (4 Sept) I'm still awaiting status on what parts will have to be ordered. I drove it 6mi there under its own power after confirming w/ the service department that a solid amber CEL and limp mode meant I could still make the short trip.
I'm genuinely hoping that serious engine work won't be necessary on a truck that's barely past 3mo old with about 6k mi on the clock. I guess the best case scenario is a new crankshaft position sensor, maybe a new timing chain tensioner (read about this plaguing generations past), and I'd guess a leak-down test for good measure to be reasonably sure the internals check out.
Worst case? Who knows.
To further complicate matters, I'm stuck out-of-town in a hotel I'd planned to check out of this past Saturday; luckily, I can work from here. Somehow I have a sneaking suspicion though that the Roadside Assistance benefit involving "reasonable reimbursement of out-of-pocket expenses if a warranty-related disablement occurs more than 50 miles from home" won't be as clear-cut as the verbiage makes it seem.