Intermittent Ecu Cylinder Shutdown Events
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Intermittent Ecu Cylinder Shutdown Events
(Cross-post. Hoping that this sounds familiar to someone)
2018 D5 HSE Si6 with ~110,000 miles.
Vehicle history: Long block was replaced under extended warranty after #6 cylinder was positive for a blown head gasket at about 99,000 miles (phew!) Cause for the head gasket failure not know.
Event History: this has happened both before the long block and after. most recently, right before a 10hr Thanksgiving road trip where luckily we could limp back home and switch to another car. I don’t have info on what parts survived the swap and which ones didn’t, although i can check w the dealer.
Event Details: The vehicle runs absolutely perfectly (at least to the driver). All of a sudden (anecdotally, maybe during slow speed turns), the vehicle will start to shudder, power is drastically reduced, CEL light is on and/or flashing. Very disconcerting. it’s clear that not all cylinders are firing just from the rough running engine and lack of power. However, shutting the car off and restarting can clear the symptoms and the car is back to normal! What the actual f*ck.
are these misfires that appear and force the ecu to protect itself? they are obviously intermittent and does not happen very often. maybe four times in the last 25k miles. what are possible issues?
- a failing 02 sensor?
- a failing fuel pump?
- something else?
I don’t have the codes yet from this most recent event, but i will post em. i am more interested in folks’ experience or gut reactions.
Any help would be very much appreciated. again, i will post codes. This is so unnerving that confidence in car has been shaken despite being restored after replacing the engine (runs so strong and better mileage too!).
ok, i needed to wait until post-thanksgiving coma to get that out. Cheers to all.
2018 D5 HSE Si6 with ~110,000 miles.
Vehicle history: Long block was replaced under extended warranty after #6 cylinder was positive for a blown head gasket at about 99,000 miles (phew!) Cause for the head gasket failure not know.
Event History: this has happened both before the long block and after. most recently, right before a 10hr Thanksgiving road trip where luckily we could limp back home and switch to another car. I don’t have info on what parts survived the swap and which ones didn’t, although i can check w the dealer.
Event Details: The vehicle runs absolutely perfectly (at least to the driver). All of a sudden (anecdotally, maybe during slow speed turns), the vehicle will start to shudder, power is drastically reduced, CEL light is on and/or flashing. Very disconcerting. it’s clear that not all cylinders are firing just from the rough running engine and lack of power. However, shutting the car off and restarting can clear the symptoms and the car is back to normal! What the actual f*ck.
are these misfires that appear and force the ecu to protect itself? they are obviously intermittent and does not happen very often. maybe four times in the last 25k miles. what are possible issues?
- a failing 02 sensor?
- a failing fuel pump?
- something else?
I don’t have the codes yet from this most recent event, but i will post em. i am more interested in folks’ experience or gut reactions.
Any help would be very much appreciated. again, i will post codes. This is so unnerving that confidence in car has been shaken despite being restored after replacing the engine (runs so strong and better mileage too!).
ok, i needed to wait until post-thanksgiving coma to get that out. Cheers to all.
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Richard Gallant
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Oct 22, 2019 05:41 PM