StabiliTrak Issues from . . . Low Compression? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

RedstickSS · 08-01-2021, 07:40 PM

Hopefully you guys can help out a newbie, and I apologize if this has already been covered in another thread and if it seems long-winded.

I bought a '12 SS convertible two years ago. It's one of those cars I thought I'd never own and was ecstatic that one was parked in my driveway. It's been a blast to drive and have fun in - until 2 months ago when my CEL starting coming on. About the same time I started seeing the "Service StabiliTrak" message pop up. I got the codes P0306 and U0401 from my code reader, so I changed the plugs and plug wires then cleared the codes. It seemed fine afterwards, then the CEL came back a few days later. Pulled the same codes, P0306 and U0401, and the StabiliTrak message started appearing more frequently, especially at idle or speeds under 50. I took it to a dealership since I figured the problem wasn't something I could fix on my own. The diagnosis wasn't good.

Low compression on Cylinder #6 was leading to the StabiliTrak message. Their recommendation: a new engine. This made sense because the engine began to feel like it was misfiring. The cost of a new block puts getting one out of the question, so I starting watching some YouTube videos to get a better understanding of what to do about low compression. When I thought about the tell-tale signs, my car's not smoking and there's no oil in the coolant or vice-versa. When I pulled the plug from #6, no signs of oil on that either. I'm guessing I have a burned valve and that replacing the cylinder head would be a cost-effective solution.

I plan on taking it to an engine shop in town for a second opinion, but I wanted to see what you guys thought. Can this engine be saved or should I start stacking a lot of pennies?

morepowerjoe · 08-02-2021, 02:25 AM

What you need to have done is a leak down test to verify that it is a valve and not the rings.

RedstickSS · 09-22-2021, 02:45 PM

So far I haven't been able to find a shop that performs leak down testing, let alone one that's even heard of it. I was referred to a local speed shop that's familiar with these engines and set up an appointment, but that was a month ago with no reply.

I called another shop to further diagnose it but they mentioned something that seems "off" to me. I made it a point to mention I have the LS3, but they said all GM vehicles after 2007 have active fuel management regardless of the transmission type. The mechanic that answered mentioned they've seen problems with the engine with the lifters and camshafts, and I could understand that if I had the L99.

Can anyone shed some light on this? It's been my understanding that the LS3 does not have the AFM system installed - or do they know something I don't?

gtstorey · 09-22-2021, 02:54 PM

The LS3 doesn't have active fuel management, but it is probably the rare GM V8 engine without it since about 2007. If you aren't dealing with a speed shop, I'm not that surprised the mechanic wasn't used to it.

cdb95z28 · 09-22-2021, 05:35 PM

Ignore the Service Stabilitrak message and the U0401 code. The U0401 is an invalid data code that comes BECAUSE of the P0306. In simple terms the PCM throws the P0306 and the Stabilitrak/Traction Control module recognizes this that it cannot trust the data from the PCM. So it throws the U0401. Once you fix and clear the misfire P0306 code, the U0401 will disappear.

AlanRubin · 09-23-2021, 04:56 AM

Quote:

Originally Posted by cdb95z28

Ignore the Service Stabilitrak message and the U0401 code. The U0401 is an invalid data code that comes BECAUSE of the P0306. In simple terms the PCM throws the P0306 and the Stabilitrak/Traction Control module recognizes this that it cannot trust the data from the PCM. So it throws the U0401. Once you fix and clear the misfire P0306 code, the U0401 will disappear.

That's a total load of shit right there...

Yeah, listen to this guy, you'll be fixed in a jiffy...

cdb95z28 · 09-26-2021, 07:12 AM

Quote:

Originally Posted by AlanRubin

That's a total load of shit right there...

Yeah, listen to this guy, you'll be fixed in a jiffy...

If you're gonna call bs, well, give us all the proper explanation for why I'm wrong.

From the OP:

"Low compression on Cylinder #6 was leading to the StabiliTrak message."
I gave further explanation why that is happening. You, not so much.............

0stones0 · 09-26-2021, 08:27 AM

RedstickSS · 10-08-2021, 03:18 PM

Picked up my car from the repair shop. They showed me the old parts and what happened.

Compression on #6 was down to 21%. The culprit was the lifter for #6 intake being worn pretty bad and damaging a cam lobe, causing it to stay open longer than normal. No problems with the heads or the block. In all they replaced lifters in both banks and the camshaft. Now it's back to making happy, healthy V8 noises.

It certainly wasn't cheap to repair, but I can't argue with the results and it was half of what an engine swap would've cost. Now all it needs a good wash.

0stones0 · 10-08-2021, 05:01 PM

Quote:

Originally Posted by RedstickSS

Picked up my car from the repair shop. They showed me the old parts and what happened.

Compression on #6 was down to 21%. The culprit was the lifter for #6 intake being worn pretty bad and damaging a cam lobe, causing it to stay open longer than normal. No problems with the heads or the block. In all they replaced lifters in both banks and the camshaft. Now it's back to making happy, healthy V8 noises.

It certainly wasn't cheap to repair, but I can't argue with the results and it was half of what an engine swap would've cost. Now all it needs a good wash.

Glad you got it sorted.

cdb95z28 · 10-08-2021, 07:14 PM

Quote:

Originally Posted by RedstickSS

Picked up my car from the repair shop. They showed me the old parts and what happened.

Compression on #6 was down to 21%. The culprit was the lifter for #6 intake being worn pretty bad and damaging a cam lobe, causing it to stay open longer than normal. No problems with the heads or the block. In all they replaced lifters in both banks and the camshaft. Now it's back to making happy, healthy V8 noises.

It certainly wasn't cheap to repair, but I can't argue with the results and it was half of what an engine swap would've cost. Now all it needs a good wash.

Good to hear it's back

And the Service Stabilitrak message and U0401? It magically went away?

morepowerjoe · 10-09-2021, 01:13 AM

Yeah I'm glad you got it fixed too. I knew it had to be something with the valves that's why I recommended a leak down test. It's a good thing it didn't destroy the engine. But I can't believe you didn't go with a cam upgrade but I guess a stock engine has it's enjoyment as well, sometimes I miss mine. lol.

RedstickSS · 10-09-2021, 12:56 PM

Thanks for everyone's feedback. So far, no codes, lights, or anything funny going on. As far as a cam and other upgrades,

.

PaulsSS · 10-09-2021, 01:09 PM

Nice. what did it cost? I was quoted around 3k cam and lifters installed at a independent.

08-01-2021, 07:40 PM	#1
RedstickSS Drives: '05 Colorado, '12 Camaro SS Join Date: Mar 2021 Location: Baton Rouge, LA Posts: 6 View My Garage	StabiliTrak Issues from . . . Low Compression? Hopefully you guys can help out a newbie, and I apologize if this has already been covered in another thread and if it seems long-winded. I bought a '12 SS convertible two years ago. It's one of those cars I thought I'd never own and was ecstatic that one was parked in my driveway. It's been a blast to drive and have fun in - until 2 months ago when my CEL starting coming on. About the same time I started seeing the "Service StabiliTrak" message pop up. I got the codes P0306 and U0401 from my code reader, so I changed the plugs and plug wires then cleared the codes. It seemed fine afterwards, then the CEL came back a few days later. Pulled the same codes, P0306 and U0401, and the StabiliTrak message started appearing more frequently, especially at idle or speeds under 50. I took it to a dealership since I figured the problem wasn't something I could fix on my own. The diagnosis wasn't good. Low compression on Cylinder #6 was leading to the StabiliTrak message. Their recommendation: a new engine. This made sense because the engine began to feel like it was misfiring. The cost of a new block puts getting one out of the question, so I starting watching some YouTube videos to get a better understanding of what to do about low compression. When I thought about the tell-tale signs, my car's not smoking and there's no oil in the coolant or vice-versa. When I pulled the plug from #6, no signs of oil on that either. I'm guessing I have a burned valve and that replacing the cylinder head would be a cost-effective solution. I plan on taking it to an engine shop in town for a second opinion, but I wanted to see what you guys thought. Can this engine be saved or should I start stacking a lot of pennies? Last edited by RedstickSS; 08-04-2021 at 09:02 PM.

08-02-2021, 02:25 AM	#2
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,093	What you need to have done is a leak down test to verify that it is a valve and not the rings. __________________ DSS FX Forged Pistons, Eagle ESP L19 Forged Rods, ARP Head and Main Studs, TSP PRC 260 CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Performance Racing Lifters, CHE Trunnions , Molly Pushrods, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP 1 7/8" Longtubes with 3" TSP Exhaust, ZL1 Fuel Pump, Mishimoto Radiator, Mishimoto Oil Cooler, Tru Cool 40k Tranny Cooler, 3600 Circle D Converter, Fluid Dynamics Balancer Build Thread https://www.camaro5.com/forums/showthread.php?t=609817

09-22-2021, 05:35 PM	#5
cdb95z28 Drives: 2022 1SS 1LE A10 BCD WCT+PDR Join Date: Mar 2008 Location: Johnstown, PA Posts: 3,200	Ignore the Service Stabilitrak message and the U0401 code. The U0401 is an invalid data code that comes BECAUSE of the P0306. In simple terms the PCM throws the P0306 and the Stabilitrak/Traction Control module recognizes this that it cannot trust the data from the PCM. So it throws the U0401. Once you fix and clear the misfire P0306 code, the U0401 will disappear. __________________ 2022 1SS 1LE A10 BCD WCT+PDR2014 1SS 1LE NPP RECARO SIM-SOLD1995 Z28 M6 GSC PGM-SOLD1975 NOVA COUPE 300HP 350 TH350 FLASH RED-SOLD

09-26-2021, 08:27 AM	#8
0stones0 It don’t come easy. Drives: 2010 2SS RS M6 Join Date: May 2014 Location: WI Posts: 2,186 View My Garage	__________________

10-09-2021, 01:13 AM	#12
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,093	Yeah I'm glad you got it fixed too. I knew it had to be something with the valves that's why I recommended a leak down test. It's a good thing it didn't destroy the engine. But I can't believe you didn't go with a cam upgrade but I guess a stock engine has it's enjoyment as well, sometimes I miss mine. lol. __________________ DSS FX Forged Pistons, Eagle ESP L19 Forged Rods, ARP Head and Main Studs, TSP PRC 260 CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Performance Racing Lifters, CHE Trunnions , Molly Pushrods, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP 1 7/8" Longtubes with 3" TSP Exhaust, ZL1 Fuel Pump, Mishimoto Radiator, Mishimoto Oil Cooler, Tru Cool 40k Tranny Cooler, 3600 Circle D Converter, Fluid Dynamics Balancer Build Thread https://www.camaro5.com/forums/showthread.php?t=609817

09-22-2021, 02:45 PM	#3
RedstickSS Drives: '05 Colorado, '12 Camaro SS Join Date: Mar 2021 Location: Baton Rouge, LA Posts: 6 View My Garage	So far I haven't been able to find a shop that performs leak down testing, let alone one that's even heard of it. I was referred to a local speed shop that's familiar with these engines and set up an appointment, but that was a month ago with no reply. I called another shop to further diagnose it but they mentioned something that seems "off" to me. I made it a point to mention I have the LS3, but they said all GM vehicles after 2007 have active fuel management regardless of the transmission type. The mechanic that answered mentioned they've seen problems with the engine with the lifters and camshafts, and I could understand that if I had the L99. Can anyone shed some light on this? It's been my understanding that the LS3 does not have the AFM system installed - or do they know something I don't?

09-22-2021, 02:54 PM	#4
gtstorey Drives: 2010 Camaro SS2,L99, LSA SC Join Date: Aug 2017 Location: Huntsville, AL Posts: 2,143	The LS3 doesn't have active fuel management, but it is probably the rare GM V8 engine without it since about 2007. If you aren't dealing with a speed shop, I'm not that surprised the mechanic wasn't used to it.

10-08-2021, 03:18 PM	#9
RedstickSS Drives: '05 Colorado, '12 Camaro SS Join Date: Mar 2021 Location: Baton Rouge, LA Posts: 6 View My Garage	Picked up my car from the repair shop. They showed me the old parts and what happened. Compression on #6 was down to 21%. The culprit was the lifter for #6 intake being worn pretty bad and damaging a cam lobe, causing it to stay open longer than normal. No problems with the heads or the block. In all they replaced lifters in both banks and the camshaft. Now it's back to making happy, healthy V8 noises. It certainly wasn't cheap to repair, but I can't argue with the results and it was half of what an engine swap would've cost. Now all it needs a good wash.

10-09-2021, 12:56 PM	#13
RedstickSS Drives: '05 Colorado, '12 Camaro SS Join Date: Mar 2021 Location: Baton Rouge, LA Posts: 6 View My Garage	Thanks for everyone's feedback. So far, no codes, lights, or anything funny going on. As far as a cam and other upgrades, .

10-09-2021, 01:09 PM	#14
PaulsSS Drives: 15SS Camaro Join Date: Dec 2020 Location: US Posts: 345	Nice. what did it cost? I was quoted around 3k cam and lifters installed at a independent.