LLT Experts I need your help! - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

lscamaro · 04-08-2015, 10:31 PM

I need the help from all the LLT geniuses who still roam around here. I posted in another thread but I'm posting here again, I'm having issues with my LLT. I'm hoping I can get some ideas tossed around to maybe figure out the root of this problem. Here's what happened:

On a drive back from out of town, about 10 miles out from arriving home, I felt the car struggle while going up a hill in cruise control. The car downshifted like normal but upon making up the hill, it didn't switch gears and accelerated on its own. Gf even thought I was being dumb by "showing off" but the car was doing it on its own. A few miles later, the dash lit up with the traction control, ABS, and service stabilitrak lights coming on. No CEL. I kept going hoping to make it home. Finally, I made it in town a couple of minutes later but upon reaching the first stop light, the RPMs dropped all the way down to 0, and the engine died on me. I tried to turn it on, and it struggled on the first attempt. I tried again, and on the second attempt it struggled again but turned on. I raced to my GF house since I was only a couple of blocks away and her house was closer to me. We got there and I turned the car off, checked under the hood and all looked normal. I left her house, car fired right up, and I tried to make it to a local auto zone to try to get a code reader to see what came up. Well I didn't even make it 4 blocks when the RPMs again dipped on me and the car died. I tried to give it gas for the RPMs not to dip but it did nothing. That was it after that.
I tried to turn the car on and it would turn on but the RPMs would dip and the engine would die immediately. It wouldn't idle. Fair enough, we called a tow truck and had it towed to my house. The next day I turned on the car, and this time it fired up but it was backfiring and knocking horrendously. Turned it off. Had OnStar run a diagnostic and it came back that the CEL light was malfunctioning and only thing coming up was a O2 sensor code for running rich. Which I noticed when I could smell gas from the exhaust. I reset the battery.
That brings us to today, it fired right up, no knocking and no backfiring. But when I took it out for a drive, all power was gone. Had OnStar run another diagnostic and they said nothing came up this time.

Any ideas? Sorry for the lengthy post. Could it be timing chains, leaks, electrical, etc? Any and all help is welcome!

TooCool5 · 04-09-2015, 11:20 AM

Timing chains almost always set a code. Can't remember P0008?
Sounds like you have something else going on.
Could pull the valve covers to check. Maybe consult a dealership mechanic
who frequently works on the LLT.

According to this post:
A rattling sound especially on cold start-up is one of the early warning signs slack is developing.
http://www.certifiedmastertech.com/w...hain-problems/

KMPrenger · 04-09-2015, 12:50 PM

What mods do you have done to the car? Are you running a ported LLT intake?

EDIT:

OK...never mind I saw in the other thread you posted this: "The only things left are my vararam, the mace spacer, and my catch can (which apparently isn't doing a good job at all)."

between the Vararam, and the spacer, do you think you could have a bad vacuum leak? A leak will definitely cause bad idle conditions, but would have to be pretty bad for the car to die I'd think. I'd pull the vararam off at least and check it. If you think its worth doing, and still have the stock intake, I'd throw that puppy back on there (and remove the spacer as well) and see what happens.

hworth18 · 04-09-2015, 01:01 PM

Check to make sure the clamps on Intake are tightened down. I had a Vararam and the screw clamp on the throttle body side kept loosening up.

lscamaro · 04-09-2015, 02:54 PM

Quote:

Originally Posted by KMPrenger

What mods do you have done to the car? Are you running a ported LLT intake?

EDIT:

OK...never mind I saw in the other thread you posted this: "The only things left are my vararam, the mace spacer, and my catch can (which apparently isn't doing a good job at all)."

between the Vararam, and the spacer, do you think you could have a bad vacuum leak? A leak will definitely cause bad idle conditions, but would have to be pretty bad for the car to die I'd think. I'd pull the vararam off at least and check it. If you think its worth doing, and still have the stock intake, I'd throw that puppy back on there (and remove the spacer as well) and see what happens.

I did have the ported manifold, why? I don't anymore though. I've removed everything to see what happens and it turned on, idled fine and I took it for a drive and all the power is gone.

Quote:

Originally Posted by hworth18

Check to make sure the clamps on Intake are tightened down. I had a Vararam and the screw clamp on the throttle body side kept loosening up.

I took off the vararam to see what happens.

TooCool5 · 04-09-2015, 09:23 PM

This may be a shot in the dark but here goes, have you cleaned your MAF lately?

lscamaro · 04-09-2015, 09:57 PM

Yes I have, clean it every 2-3 oil changes.

lscamaro · 04-09-2015, 09:59 PM

Well to update this thread, a mechanic who is a friend of our family came over and just as expected, NOTHING bad happens.... of course. He took it out for a drive anyway and said he didn't feel anything. Something weird though is that when we hooked up the scanner to it, nothing came up except for a code about the check engine light being broken.

TooCool5 · 04-10-2015, 01:31 PM

Quote:

Originally Posted by lscamaro

Well to update this thread, a mechanic who is a friend of our family came over and just as expected, NOTHING bad happens.... of course. He took it out for a drive anyway and said he didn't feel anything. Something weird though is that when we hooked up the scanner to it, nothing came up except for a code about the check engine light being broken.

Could this be a bad tank of fuel? We have seen this on LLT's before.
http://www.camaro5.com/forums/showth...light=chemtool

CEL Light broken, that's odd, does it light up when you key up the car?
Maybe the Bosch ECU/PCM is going out. Later models have fins on them to keep them cool.
Could it have a connectivity problem at the harness? I once had an eclipse that had no cell, after
unhooking the battery and putting the ECU harness on and off a few times, the cel started working.
Got my code and fixed the poor running car.

Keep Trying all the easy stuff first through process of elimination you should find it.

Ventmaster · 04-10-2015, 02:41 PM

+1 on the bad or contaminated gas theory.

Also how many miles on the car? And have you looked at the sparkplugs- maybe one from each side just to be sure? Maybe a cat getting plugged up-

Good luck and keep us posted!

lscamaro · 04-12-2015, 06:00 PM

Quote:

Originally Posted by Ventmaster

+1 on the bad or contaminated gas theory.

Also how many miles on the car? And have you looked at the sparkplugs- maybe one from each side just to be sure? Maybe a cat getting plugged up-

Good luck and keep us posted!

About 84k on the car right now. Would contaminated gas really cause all this? Especially the car dying completely? I understand it might cause backfiring and some knocking but causing a car to completely die?

Wouldn't a spark plug also not let the car turn on smoothly?

menendez1293 · 04-12-2015, 07:27 PM

Right now I am thinking a Vacuum leak somewhere, a bad tank of gas/faulty injector or a bad spark plug. I would start by pulling the plugs and see if you can find anything there. Then I would check any vacuum lines that you can.

I know its not the LLT, but I recently had a vacuum leak in the PCV system of my Cruze Eco and that caused it to idle horribly. It was to the point where if I was at a light long enough the RPMs would dip close to the point where the motor would stall. Luckily for me, that was a common problem with the 1.4T in the Cruze/Sonic so it wasn't hard to find once I knew what I was looking for.

lscamaro · 04-19-2015, 10:55 PM

Well to try to get to the bottom of the problem, I decided to try disconnecting the battery first to try to get rid of any possible electrical gremlins. I also took off my vararam and mace spacer since I wanted to check the manifold filling was still intact. It was. And then I let it sit overnight. I turned it on in the morning and now nothing. I don't know what happened. Its been working fine since. I took it out, beat on it a bit to hopefully replicate the problem and nothing. I have no idea what happened and can't figure it out because the car is now acting perfectly. Anyone got any ideas? I'm glad its fine for now but without knowing what happened to it it makes me a bit paranoid the car might leave me on the side of the road at any time.

IBM camaro · 04-19-2015, 11:23 PM

I'm sorry man it could have been a problem with the ECU that glitched out, either that or a short somewhere in some computer component, the battery being off makes me think that it was just a glitch because if it was a physical problem it would have happened even after you let it sit with the battery disconnected, I hope it gets better man my bmw e90 won't start anymore and it might be the ECU electrical stuff sucks

04-08-2015, 10:31 PM	#1
lscamaro Drives: 2011 CGM Camaro LS A6 Join Date: Jan 2011 Location: San Antonio, Texas Posts: 10,305	LLT Experts I need your help! I need the help from all the LLT geniuses who still roam around here. I posted in another thread but I'm posting here again, I'm having issues with my LLT. I'm hoping I can get some ideas tossed around to maybe figure out the root of this problem. Here's what happened: On a drive back from out of town, about 10 miles out from arriving home, I felt the car struggle while going up a hill in cruise control. The car downshifted like normal but upon making up the hill, it didn't switch gears and accelerated on its own. Gf even thought I was being dumb by "showing off" but the car was doing it on its own. A few miles later, the dash lit up with the traction control, ABS, and service stabilitrak lights coming on. No CEL. I kept going hoping to make it home. Finally, I made it in town a couple of minutes later but upon reaching the first stop light, the RPMs dropped all the way down to 0, and the engine died on me. I tried to turn it on, and it struggled on the first attempt. I tried again, and on the second attempt it struggled again but turned on. I raced to my GF house since I was only a couple of blocks away and her house was closer to me. We got there and I turned the car off, checked under the hood and all looked normal. I left her house, car fired right up, and I tried to make it to a local auto zone to try to get a code reader to see what came up. Well I didn't even make it 4 blocks when the RPMs again dipped on me and the car died. I tried to give it gas for the RPMs not to dip but it did nothing. That was it after that. I tried to turn the car on and it would turn on but the RPMs would dip and the engine would die immediately. It wouldn't idle. Fair enough, we called a tow truck and had it towed to my house. The next day I turned on the car, and this time it fired up but it was backfiring and knocking horrendously. Turned it off. Had OnStar run a diagnostic and it came back that the CEL light was malfunctioning and only thing coming up was a O2 sensor code for running rich. Which I noticed when I could smell gas from the exhaust. I reset the battery. That brings us to today, it fired right up, no knocking and no backfiring. But when I took it out for a drive, all power was gone. Had OnStar run another diagnostic and they said nothing came up this time. Any ideas? Sorry for the lengthy post. Could it be timing chains, leaks, electrical, etc? Any and all help is welcome! __________________ Click Picture for Build Thread

04-09-2015, 11:20 AM	#2
TooCool5 Drives: 2010 Camaro 1LS 3.6 LLT V6 325 HP Join Date: May 2009 Location: LS Posts: 4,242 View My Garage	Timing chains almost always set a code. Can't remember P0008? Sounds like you have something else going on. Could pull the valve covers to check. Maybe consult a dealership mechanic who frequently works on the LLT. According to this post: A rattling sound especially on cold start-up is one of the early warning signs slack is developing. http://www.certifiedmastertech.com/w...hain-problems/ __________________ 2010 Camaro Auto, Inferno Orange, Titanium Interior, Gearhead Wheels AIRAID CAI Last edited by TooCool5; 04-09-2015 at 11:34 AM.

04-09-2015, 12:50 PM	#3
KMPrenger Drives: 16 Camaro SS, 15 Colorado Join Date: May 2009 Location: Jefferson City, Missouri Posts: 13,944	What mods do you have done to the car? Are you running a ported LLT intake? EDIT: OK...never mind I saw in the other thread you posted this: "The only things left are my vararam, the mace spacer, and my catch can (which apparently isn't doing a good job at all)." between the Vararam, and the spacer, do you think you could have a bad vacuum leak? A leak will definitely cause bad idle conditions, but would have to be pretty bad for the car to die I'd think. I'd pull the vararam off at least and check it. If you think its worth doing, and still have the stock intake, I'd throw that puppy back on there (and remove the spacer as well) and see what happens. __________________ 2016 Camaro 1SS - 8-speed - NPP - Black bowties 2010 Camaro 1LT V6 (Sold. I will miss her!)

04-09-2015, 01:01 PM	#4
hworth18 Jus' Cruzin Drives: 2017 Camaro 1SS Krypton Green Join Date: Oct 2012 Location: Northeast Oklahoma Posts: 1,108 View My Garage	Check to make sure the clamps on Intake are tightened down. I had a Vararam and the screw clamp on the throttle body side kept loosening up. __________________ “The moment you think you know what’s going on in a women’s head, is the moment your goose is well and truly cooked” -Howard Stark

04-09-2015, 09:23 PM	#6
TooCool5 Drives: 2010 Camaro 1LS 3.6 LLT V6 325 HP Join Date: May 2009 Location: LS Posts: 4,242 View My Garage	This may be a shot in the dark but here goes, have you cleaned your MAF lately? __________________ 2010 Camaro Auto, Inferno Orange, Titanium Interior, Gearhead Wheels AIRAID CAI

04-09-2015, 09:57 PM	#7
lscamaro Drives: 2011 CGM Camaro LS A6 Join Date: Jan 2011 Location: San Antonio, Texas Posts: 10,305	Yes I have, clean it every 2-3 oil changes. __________________ Click Picture for Build Thread

04-09-2015, 09:59 PM	#8
lscamaro Drives: 2011 CGM Camaro LS A6 Join Date: Jan 2011 Location: San Antonio, Texas Posts: 10,305	Well to update this thread, a mechanic who is a friend of our family came over and just as expected, NOTHING bad happens.... of course. He took it out for a drive anyway and said he didn't feel anything. Something weird though is that when we hooked up the scanner to it, nothing came up except for a code about the check engine light being broken. __________________ Click Picture for Build Thread

04-10-2015, 02:41 PM	#10
Ventmaster Drives: 2017 1SS 6spd Join Date: Jan 2011 Location: Utah Posts: 2,879	+1 on the bad or contaminated gas theory. Also how many miles on the car? And have you looked at the sparkplugs- maybe one from each side just to be sure? Maybe a cat getting plugged up- Good luck and keep us posted!

04-12-2015, 07:27 PM	#12
menendez1293 Emerald Coast Camaros Drives: 2010 Camaro 2LT/RS M6 Join Date: Nov 2009 Location: Tallahassee FL Posts: 9,687 View My Garage	Right now I am thinking a Vacuum leak somewhere, a bad tank of gas/faulty injector or a bad spark plug. I would start by pulling the plugs and see if you can find anything there. Then I would check any vacuum lines that you can. I know its not the LLT, but I recently had a vacuum leak in the PCV system of my Cruze Eco and that caused it to idle horribly. It was to the point where if I was at a light long enough the RPMs would dip close to the point where the motor would stall. Luckily for me, that was a common problem with the 1.4T in the Cruze/Sonic so it wasn't hard to find once I knew what I was looking for.

04-19-2015, 10:55 PM	#13
lscamaro Drives: 2011 CGM Camaro LS A6 Join Date: Jan 2011 Location: San Antonio, Texas Posts: 10,305	Well to try to get to the bottom of the problem, I decided to try disconnecting the battery first to try to get rid of any possible electrical gremlins. I also took off my vararam and mace spacer since I wanted to check the manifold filling was still intact. It was. And then I let it sit overnight. I turned it on in the morning and now nothing. I don't know what happened. Its been working fine since. I took it out, beat on it a bit to hopefully replicate the problem and nothing. I have no idea what happened and can't figure it out because the car is now acting perfectly. Anyone got any ideas? I'm glad its fine for now but without knowing what happened to it it makes me a bit paranoid the car might leave me on the side of the road at any time. __________________ Click Picture for Build Thread

04-19-2015, 11:23 PM	#14
IBM camaro Texas HT5 Drives: IBM Join Date: Oct 2012 Location: Tx Posts: 1,335	I'm sorry man it could have been a problem with the ECU that glitched out, either that or a short somewhere in some computer component, the battery being off makes me think that it was just a glitch because if it was a physical problem it would have happened even after you let it sit with the battery disconnected, I hope it gets better man my bmw e90 won't start anymore and it might be the ECU electrical stuff sucks