2016 Tahoe Shakes RPM Drops and engine dies

[Dabadelic]

Recently I had some issues with my 2016 Tahoe. To make a long story short, very infrequently while at idle this truck will begin to shake and the rpm drop to 250 or so and bounce from there to about 500 before it dies or I shut it off. When I restart the truck it takes it 6-10 seconds before it will fire instead of the normal 1.5 seconds. At this time I was getting P50D code. After this happens the truck acts mostly normal and I have been able to drive 600 miles or more between incidents. I have noticed while at stop lights a vibration and can see the rpms dropping to about 800 and bouncing back up to 1000 while this is happening.

The dealer found #3 cylinder not firing right and determined it needed new injectors so they replaced the left bank and all 8 plugs and wires. New Radiator. Pressure tested all good. Drove it 400 miles all seemed ok. It just did the whole engine shake and died again about an hour ago. Did start back up after 2 attempts with no error codes showing. I shut it back off.

What would cause the engine fuel supply to get disrupted only every now and then and otherwise act fine for hundreds of miles?

 

[Big Mama]

How old is the battery?

 

[Dabadelic]

How old is the battery?

3 months.

 

[gat0r]

how many miles do you have?



a user on another forum reported bad fuel. they pumped & cleaned tank & had to replace 1 injector due to crud in system.

another said, dealer performed a global recalibration on the ecu and did valve/injector and intake cleaning.



per the OBD site:
Causes for this code may include:
-Vacuum or air intake leaks
-Bad spark plugs, plug boots, or ignition coils
-Insufficient fuel pressure/volume
-Defective ECT sensor
-Shorted or open circuits or connectors

 

[1BADI5]

Sounds like the dealer just engaged the parts cannon and didn't actually diagnose the issue.

- Call them and ask them what the long and short term fuel trims were.
- dead cyl #3, did they pull the valve cover to see if the lifter was sticking? The lack of movement in the rocker arm would be indicative of a sticking/stuck lifter.

Where your issues are intermittent, actual diagnostics needs to be done. All they did was look in the system and saw, this is the most likely cause - replace this, this and that.......fire and forget.

 

[Thaxton80]

Recently I had some issues with my 2016 Tahoe. To make a long story short, very infrequently while at idle this truck will begin to shake and the rpm drop to 250 or so and bounce from there to about 500 before it dies or I shut it off. When I restart the truck it takes it 6-10 seconds before it will fire instead of the normal 1.5 seconds. At this time I was getting P50D code. After this happens the truck acts mostly normal and I have been able to drive 600 miles or more between incidents. I have noticed while at stop lights a vibration and can see the rpms dropping to about 800 and bouncing back up to 1000 while this is happening.

The dealer found #3 cylinder not firing right and determined it needed new injectors so they replaced the left bank and all 8 plugs and wires. New Radiator. Pressure tested all good. Drove it 400 miles all seemed ok. It just did the whole engine shake and died again about an hour ago. Did start back up after 2 attempts with no error codes showing. I shut it back off.

What would cause the engine fuel supply to get disrupted only every now and then and otherwise act fine for hundreds of miles?

Did you ever find the issue? Mine has been dropping for a while but just now started the delay in starting.

 

[Bob2C]

Check the grounding cable on the back of the engine. It’s on the driver side I believe. Also check your battery cables. I read in other forums that it has been an issue. Check the resistance and the grounding.