5.3L Idle Vibration/Rough Idle Surge

Dropsix · January 23, 2015

The higher idle rpm seemed to help smooth things out a bit. Blackbear made the idle around 530-550 rpm. I guess I should have checked on the autocal after i uploaded. But it is definitely better. No more surging either. You can tell the truck is running, but its not nearly as bad.

How is it one month in now?

Silverado-Hareek · January 23, 2015

When I spoke with RX regarding the catch can, the guy on the phone informed me that at 11,800 miles when I installed my can, I probably already had a decent amount of build-up on my valves and may notice a rough idle at start up until the engine reaches operating temp. I get an intermittent rough idle that occurs randomly regardless of engine temperature but I wonder if this rough idling described in this thread and in my case is related to deposit build up on the valves?

Edited January 23, 2015 by Silverado-Hareek

fondupot · January 23, 2015

How is it one month in now?

Still good. Way better than stock. I had to return to stock for a few days and I was so annoyed at the idle vibration.

Dropsix · February 18, 2015

Does anyone else idle under 500 rpm at a stop light?

Dropsix · February 20, 2015

Still good. Way better than stock. I had to return to stock for a few days and I was so annoyed at the idle vibration.

Brought my truck into the dealer complaining about the misfire.

Obviously they said there was no misfire. I should have sat in the truck with the service advisor and made him see for himself.

I understand a tune would improve stuff but I feel like its insane Id have to do that. This is the first new car that I buy ever.

hotrodz37 · March 25, 2015

I am going to give this stuff a whirl this weekend and report back. One member used it and reported great things and any hesitation/stumble gone.

http://crcindustries.com/auto/intake-valve-cleaner.php

Here is the write up from the other gentleman: http://www.gm-trucks...take-clean-wow/

Edited March 25, 2015 by hotrodz37

Dropsix · March 25, 2015

I had the service bulletin performed where they "re-center" the mounts.

It did nothing.

Dirtybird31 · January 26, 2016

Notice the same rpm range on mine. Going to the dealer on Thursday. Almost 18,500 will ask about the spark plugs and ignition.

Chefkoepp · July 7, 2016

Intermittent engine vibration / shudder at idle solved!

I have a 2014 tahoe. 5.3L and have worked on this for a year. You don't have an engine problem, you have a maintenance problem. This is a multi step process.

******REMOVE BATTERY CABLE******

1)The mass air flow sensor needs to be cleaned with crc mass airflow sensor cleaner about every 10k miles; especially if you have a k&n filter. Oil Coates it and it miss reads.

2) you need to remove the throttle plate (4 10mm screws) and clean the front and back of the plate thoroughly with crc throttle body cleaner. After cleaning, take a clean towel, spray cleaner in the throttle body and wipe it out with the clean towel. This needs to be done every 10k or so miles or when you notice the shudder, or it starts shifting hesitantly.

Verify the wire connection is in good condition and no wires are loose. Verify the silicone gasket is in good repair and clean. I f not replace it.

**********(IMPORTANT)**************

After re attaching the throttle plate to the throttle body you must run the recalibration sequence for the engine.

1)re attach the battery cable.

2)turn the key to on (not start ) for 15 seconds.

3) make sure all accessories are off.

4) start truck and let idle till it fully cycles. About 8 to 10 mins.

5) turn engine off remove key

6) again put key in and turn to on posit in for 15 seconds

7 start car and drive at a normal pace. Don't race it. Take it on highway and it will continue to relearn shifting points.

Additionally, you most likely also have water in your tank due to ethenol absorbing humidity from the air. You need to run 3 or 4 successive tanks of water remover or HEET through your truck. Small water slugs also give your truck a shudder. But the easy way to tell if it is water is to park face down on a steep hill and the water will go to the front of the tank and not pool around the fuel pump. If you still have the shudder, it's the throttle plate and mass airflow sensor.

It's not that hard to do this so every 10k just do it. It will also make your vehicle shift better and reduce the hum of the active fuel system management.

Problem solved.

candu · July 31, 2020

Plugging up PCV orifice and line was causing idle surging on my ecotec3 5.3. Would go from 400-700 rpm every 3 seconds cycle. Turning AC on would drag this cycling lower. Some stutter and intermittent shake type vibration. Took the PCV connection apart on drivers side, mid point above the valve cover. Sprayed a few blasts of Brake & Parts Cleaner in both directions. Back together and started it. A couple of minutes of the surging, and then it settled in to steady 550 rpm. Turning AC on drops rpm to 500 for 2 seconds, then steady at 550. Be careful that you don't get too generous with the spraying. Better to do this procedure a few times than too much all at once. Carb Cleaner would work as well.