Can’t find anyone with similar problems to me

darien kurtz · April 1

2019 Silverado facelift 5.3 103000 kms getting the generic Misfire code when I scan it it shows service esc, service parking break and a flashing CEL. It has a rough idle and clunks hard when coming to a stop almost like being rear ended. This isn’t what’s weird it also occasionally billows white smoke out of the tailpipe for around 10 seconds this only happens about once every 2000 Kms. It also backfires occasionally and sometimes is a little extra Smoky the smoke isn’t blue it’s a thick white but doesn’t smell like coolant it smells like gas the coolant and oil levels also never change the normal exhaust also smells very rich spark plugs look fine I changed them and the coils dealership says they don’t know what’s wrong with it can anyone provide me some insight?

Mike Duhaime · April 2

Try looking at this

you are past warranty but they may help you

Best to buy AllData DYI and look up issues before warranty runs out

there are a few more TSB's

#20-NA-166: Information on Malfunction Indicator Lamp (MIL) Illuminated - DTCs P050D and/or P0300 Setting on a Cold Start and/or Engine Runs Rough when Warm with No Codes - (Mar 21, 2024)

Subject:

Information on Malfunction Indicator Lamp (MIL) Illuminated – DTCs P050D and/or P0300 Setting on a Cold Start and/or Engine Runs Rough when Warm with no codes

Code P050D Description

During a cold start, the engine control module (ECM) commands dual-pulse mode during Open Loop operation to improve cold start emissions. In dual-pulse mode, the fuel injectors are energized twice during each injection event. As with misfire diagnosis, in dual-pulse mode the ECM monitors the crankshaft position sensor and the camshaft position sensor to calculate crankshaft rotation speed.

In normal operation, optimum fuel delivery during dual-pulse mode produces a steady crankshaft rotation speed. If the variations of crankshaft rotation speed exceed a calibrated value, the code P050D will be set.

Misfires on start up only, with high rates always on one cylinder, can be suspect for coolant entry at the liner to deck face casting or the casting line in the intake port of the cylinder head.

To inspect for this concern, add coolant dye to the system, run the engine through warm up, pressurize the cooling system after warming the engine to operating temperature (let the engine cool overnight) and inspect the suspect cylinder with a borescope for coolant dye evidence.

At times it may be necessary to remove the head for inspection.

If the head casting line is the concern, the intake port will be wet with a coolant oil mix.

This could be the cause of a running rough warm concern with or without codes.

The location of where the coolant is running down in the port will also look washed down.