WHELPS! I drove my car yesterday and going to place then back. I was going 75 mph and then got stuck in traffic hours and slow down from 75 mph. Bam! All the the sudden my car rough idling and bogging while I was driving. I was confused and my father was with me. He told me could be spark plugs. So, I drove to my parent's home and parked my car. I shut off then start again and it still does the same thing like Subaru. I shut it off again and pulled out my spark plugs, all spark plugs come out ok. The engine is bone stock with no tune or modified into it yet at 71,000 miles on it right now. Couldn't figure out why and what's going on with the car. I checked for pipes popped out and nope still intacted. Anybody experienced this problems ?

 

Bump, Anybody ? I don't have any check engine light pop up yet.

 

misfire bro

 

YEP, It does misfire.

 

I looked up and seeing LNF owners have rough idle or misfiring will pop up check engine light on. I have no check engine light and it has not popped up yet. Still does the same thing, it's really frustrating.

 

I'm not too sure what it may be. If you can I'd post up a video of it. With no CELs or anything, bogging and a funky idle isn't descriptive. A video will get you better answers. And have you performed an actual boost leak test or just a visual check?

 

Did you rev it really high recently? Pull valve cover and see if a lash adjuster is broke.

It's common on the LNF.

 

No, I had not rev high yet. I rev it up to 3000rpm most of the time.

 

my turbo went bad and I have misfires, you should check that

 

I pulled my spark plugs and they all seem fine.

 

Pull the valve cover and look for broken lash adjusters.

Also check the evap purge selenoid for failure.

 

Yep! It's my evap purge solenoid. I took it out and check if it blow and nope it don't blow or rattle inside solenoid. It's dead solid, I am gonna get new 1.

 

Wait, it should be solid, you should not be able to blow through the purge selenoid.

But I have had several that died and you couldn't blow through them.

I generally had a pending P04.. code that wasn't setting a CEL.

 

The video said you're not supposed to be able to blow any air through it. So it's probably fine. Another thing to check is your MAF sensor. It doesn't hurt to clean that once and a while. Just get a can of CRC Mass Airflow Sensor cleaner and spray in on the fine little wires in the MAF sensor. I was having symptoms similar to yours and that fixed it.

 

go fill your car up and if it struggles to start its the purge solenoid and if it starts fine check the lash adjusters and your maf

 

AH Crap! I took my car to Chevrolet and they will find out what's wrong with my car. Since there's no check engine light on and I can't hear to pointed out what's the problems is. I will find out either today or this coming Monday.

 

well good luck and keep us updated

 

U could just unplug the purge solinoid and see how it runs. Bad solinoid usually doesn't make car that rough.

 

I tried that and got new evap purge solenoid. Still run rough, it could be something else. I just find that hard to believe that my car was running perfect 2 days before and yesterday all day until I got stuck in traffic jam. Then BAM! Running like crap after that and 20 miles all the way to my parents. Today tried to fix the problems but couldn't figure it out. I had to take it to Chevrolet and they will find what's the exact problems then I'll fix from there.

 

Almost 90% of idling issues are VAC related. Check for vac leaks.

 

I agree with this.^ it sounds like you slipped a pipe when you let off the gas and now have a vac leak. Any black smoke out the tailpipe? Are the plugs black? I can't tell.

 

I checked my pipe and they are all bolt down tight. And surprisingly no my muffler don't puff out any black smoke at all. Plugs are not black by the way. LOL!

 

A visual on the pipes isn't enough. You have to leak test the system. Do you have stock intercooler. Was it cold where you are?

 

I have only ZZP intercooler on, I sold stock intercooler few months back. Yeah, it was cold where I am at. I don't see that is the issue here. I dropped off Chevrolet already and they will let me know on Monday for sure.

 

Boost leak test