Hi all!
My truck, 2018 Silverado 5.3L very recently developed a new issue. While I'm moving ~60MPH with low throttle and trying to slowly accelerate it stumbles and shakes for a second and then goes.
Idle is stable, wide open throttle is stable, all other regimes does not seem to exibit any issues.
I don't yet have GM-specific scan tool, but generic one does not show any codes. Check engine light is also off.
I was able to reproduce this issue dirung the transition from V4 to V8, but also in V8 only, by locking the transmission in M5.
I also found couple of thread that seem to have similar issues and they point to MAP sensor. I removed MAP sensor, checked the connectors for corrosion - found noting suspicious, reinstalled it and it the truck still shivers under low acceleration.
I also tried to log MAP, MAF, Ignition Advence, Fuel Rail Pressure and Absolute Throttle position.
MAP seems to have stable reading, wide range of expected values from almost vacuum to atmospheric pressure. It follows the Absolute Throttle Position values with a slight delay, which seems correct to me.
Fuel Rail Pressure is stable during the srivers.
The only thing I've noticed is that these shivers happen when ignition advance drops to around 5 degrees.
The truck has 68000 miles on odometer and recetly had transmission replaced with remanufactured one (3000 miles ago). Engine oil is 3000 miles old, air filter is clean. The only thing that has recently changed on a truck are rims and tires, but I doubt this has anything to do with my current problem (I went from 285/45 R22 to 285/65 R18, external diameter is 1.5% greater, but I didn't even need to recalibrate my speedometer).
The truck and myself are located in Europe (Hungary), Silverado is extremely rare here, so there are no dealerships and parts take weeks and months to arrive.
I would appreciate any advice on how to diagnose and fix this issue.
My truck, 2018 Silverado 5.3L very recently developed a new issue. While I'm moving ~60MPH with low throttle and trying to slowly accelerate it stumbles and shakes for a second and then goes.
Idle is stable, wide open throttle is stable, all other regimes does not seem to exibit any issues.
I don't yet have GM-specific scan tool, but generic one does not show any codes. Check engine light is also off.
I was able to reproduce this issue dirung the transition from V4 to V8, but also in V8 only, by locking the transmission in M5.
I also found couple of thread that seem to have similar issues and they point to MAP sensor. I removed MAP sensor, checked the connectors for corrosion - found noting suspicious, reinstalled it and it the truck still shivers under low acceleration.
I also tried to log MAP, MAF, Ignition Advence, Fuel Rail Pressure and Absolute Throttle position.
MAP seems to have stable reading, wide range of expected values from almost vacuum to atmospheric pressure. It follows the Absolute Throttle Position values with a slight delay, which seems correct to me.
Fuel Rail Pressure is stable during the srivers.
The only thing I've noticed is that these shivers happen when ignition advance drops to around 5 degrees.
The truck has 68000 miles on odometer and recetly had transmission replaced with remanufactured one (3000 miles ago). Engine oil is 3000 miles old, air filter is clean. The only thing that has recently changed on a truck are rims and tires, but I doubt this has anything to do with my current problem (I went from 285/45 R22 to 285/65 R18, external diameter is 1.5% greater, but I didn't even need to recalibrate my speedometer).
The truck and myself are located in Europe (Hungary), Silverado is extremely rare here, so there are no dealerships and parts take weeks and months to arrive.
I would appreciate any advice on how to diagnose and fix this issue.
