Reason for Motor Failure - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

GHOSST2012 · 03-07-2019, 12:10 PM

Hey guys I'm looking for some input. I have a 2012 camaro 2ss full bolt on with an f1a procharger. Motor was untouched. I have a misfire in cyl7 with oil on the cyl7 plug. The cylinder failed compression test with a 75. Shop had the heads checked and found 4 bent exhaust valves. I'm trying to figure out how this could've happened. The car was run at 9lbs of boost making 620 to the wheel on pump gas. I have an n2mb wot box with a pretty violent 2step. Do you think that's what caused the bent valves? The last time the 2 step was used was about 5 months prior to the engine failure. Car is daily driven and was procharged for 1yr 15k miles.

Batmanntexas · 03-07-2019, 01:25 PM

With 4 bent exhaust valves, only 1 cylinder had low compression? Did you perform the compression test or did the shop? Did they do a wet compression test as well?

I'd think the only way to bend a valve would be through some form of piston-to-valve contact. I don't have any experience with a 2-step, so I can't comment on that.

GHOSST2012 · 03-07-2019, 01:49 PM

I only checked the one that had the misfire. When I brought it to the shop they checked everything and confirmed cyl7 was the issue. Ended up ordering a 418 tsp short block. I just want to figure out what the original cause was so I can avoid the same issue from happening on the new motor.

bayarea408 · 03-07-2019, 02:14 PM

620 wheel on pump, what kinda fueling are you running. number 7 is notorious for being the first one to lean out when fueling starts to hit a ceiling.

ecreps · 03-07-2019, 02:21 PM

A bunch of bent valves sounds like a valvetrain issue to me. Broken timing chain, or a bunch of floated valves? Did you have an over rev situation? Are you still on stock valve springs?

GHOSST2012 · 03-07-2019, 04:32 PM

Completely upgrade fuel system with flex fuel capabilities. Definetly wasnt low on fuel.

GHOSST2012 · 03-07-2019, 04:33 PM

Stock valve train. No over rev situation but have bounced it off the rev limiter a few times.

stevieturbo · 03-07-2019, 05:20 PM

A violent 2 step can be hard on valvetrain.

And a new shortblock isnt going to fix valvetrain or bent valves lol.

bayarea408 · 03-07-2019, 08:11 PM

4 bent exhaust valves and only 1 cylinder is down? This shop has some explaining to do. I take it they set the car up and are doing the new 416 as well? Did you break any springs? Where did the tuner set your redline?

snap some pictures, this whole thing is vague its annoying.

*SSE 4 2SS* · 03-07-2019, 09:50 PM

LS3, L99, (manual or automatic) since the motor is untouched.... Was that 4 valves on one head, or the two heads. Which cylinders contained the bent valves... I'm guessing you floated some valves to have 4 bent....

What is the "rev" limiter set to, if it has been changed by the tuner. As was mentioned before, are there any broken springs, have the spring pressures been measured....

If you are running an L99 and it's untouched, I highly recommend you get a different cam and a full set of lifters, springs, etc, and swap all that out... Change the valve guides and seals.... It's entirely possible with bent valves there could be some damage to or from the valve guides, especially with the "violent" 2 Step.... Check the valve seats for any impact or material hammered into the surface from a valve coming apart or part of a piston leaving the cylinder after contact with a valve.... What did the spark plugs look like.... were all of the electrodes still in place or were they missing, burnt off or broken off.... Was any of the ceramic broken...

GHOSST2012 · 03-08-2019, 05:55 AM

I have an ls3. The rev limit is set to 6500. I wasnt told which valves were bent and there is no sign of damage anywhere else. They havent taken the pistons out of the block though. Cyl 7 plug was wet with oil on the threads even after putting in a brand new set and checking after about 4miles. Plugs were not damaged at all. After removing the heads cyl7 head port was caked in carbon/oil build up and top of piston was blackened. All other were fine.

GHOSST2012 · 03-08-2019, 05:59 AM

Here are a few pics

bayarea408 · 03-08-2019, 02:24 PM

are any of the push rods bent? sometimes when briefly over rev'd it can bend the pushrod and cause a valve float. Are there kiss markings on the piston top? scoring of the cylinder wall?

i'd look into the cylinder 7 injector as well, faulty leaky injector..drowns the cylinder causes a misfire computer shuts off injector 7 it still bleeds leaky fuel you now lean out in #7. Just a guess...

hillshooter · 03-08-2019, 02:56 PM

did the timing chain jump a tooth?

03-07-2019, 12:10 PM	#1
GHOSST2012 Drives: 2012 Camaro SS Join Date: Apr 2016 Location: Clifton NJ Posts: 162	Reason for Motor Failure Hey guys I'm looking for some input. I have a 2012 camaro 2ss full bolt on with an f1a procharger. Motor was untouched. I have a misfire in cyl7 with oil on the cyl7 plug. The cylinder failed compression test with a 75. Shop had the heads checked and found 4 bent exhaust valves. I'm trying to figure out how this could've happened. The car was run at 9lbs of boost making 620 to the wheel on pump gas. I have an n2mb wot box with a pretty violent 2step. Do you think that's what caused the bent valves? The last time the 2 step was used was about 5 months prior to the engine failure. Car is daily driven and was procharged for 1yr 15k miles.

03-07-2019, 01:25 PM	#2
Batmanntexas Drives: 2012 Camaro SS (2SS) Join Date: Aug 2012 Location: Stafford, VA Posts: 1,374 View My Garage	With 4 bent exhaust valves, only 1 cylinder had low compression? Did you perform the compression test or did the shop? Did they do a wet compression test as well? I'd think the only way to bend a valve would be through some form of piston-to-valve contact. I don't have any experience with a 2-step, so I can't comment on that. __________________ 745RWHP/634RWTQ on 93 @ 10psi 806/676 on E85 @ 10psi COTW 9/8/14

03-07-2019, 09:50 PM	#10
SSE 4 2SS Boosted Moderator Drives: Bone Stock LS3 Join Date: Sep 2009 Location: Marion Tx Posts: 15,495	LS3, L99, (manual or automatic) since the motor is untouched.... Was that 4 valves on one head, or the two heads. Which cylinders contained the bent valves... I'm guessing you floated some valves to have 4 bent.... What is the "rev" limiter set to, if it has been changed by the tuner. As was mentioned before, are there any broken springs, have the spring pressures been measured.... If you are running an L99 and it's untouched, I highly recommend you get a different cam and a full set of lifters, springs, etc, and swap all that out... Change the valve guides and seals.... It's entirely possible with bent valves there could be some damage to or from the valve guides, especially with the "violent" 2 Step.... Check the valve seats for any impact or material hammered into the surface from a valve coming apart or part of a piston leaving the cylinder after contact with a valve.... What did the spark plugs look like.... were all of the electrodes still in place or were they missing, burnt off or broken off.... Was any of the ceramic broken... __________________ If the car feels like it is on rails, you are probably driving too slow. -Ross Bentley Horsepower is how fast you hit the wall. Torque is how far you take the wall with you. “If everything seems under control, you're just not going fast enough.” Mario Andretti If you can turn, you ain't going fast enough...

03-08-2019, 05:59 AM	#12
GHOSST2012 Drives: 2012 Camaro SS Join Date: Apr 2016 Location: Clifton NJ Posts: 162	Here are a few pics Attached Images

03-08-2019, 02:24 PM	#13
bayarea408 Drives: T Join Date: Mar 2015 Location: CA Posts: 803	are any of the push rods bent? sometimes when briefly over rev'd it can bend the pushrod and cause a valve float. Are there kiss markings on the piston top? scoring of the cylinder wall? i'd look into the cylinder 7 injector as well, faulty leaky injector..drowns the cylinder causes a misfire computer shuts off injector 7 it still bleeds leaky fuel you now lean out in #7. Just a guess... Last edited by bayarea408; 03-08-2019 at 02:44 PM.

03-07-2019, 01:49 PM	#3
GHOSST2012 Drives: 2012 Camaro SS Join Date: Apr 2016 Location: Clifton NJ Posts: 162	I only checked the one that had the misfire. When I brought it to the shop they checked everything and confirmed cyl7 was the issue. Ended up ordering a 418 tsp short block. I just want to figure out what the original cause was so I can avoid the same issue from happening on the new motor.

03-07-2019, 02:14 PM	#4
bayarea408 Drives: T Join Date: Mar 2015 Location: CA Posts: 803	620 wheel on pump, what kinda fueling are you running. number 7 is notorious for being the first one to lean out when fueling starts to hit a ceiling.

03-07-2019, 02:21 PM	#5
ecreps Drives: 2014 1LE, 1996 z28 Join Date: May 2015 Location: United States Posts: 172	A bunch of bent valves sounds like a valvetrain issue to me. Broken timing chain, or a bunch of floated valves? Did you have an over rev situation? Are you still on stock valve springs?

03-07-2019, 04:32 PM	#6
GHOSST2012 Drives: 2012 Camaro SS Join Date: Apr 2016 Location: Clifton NJ Posts: 162	Completely upgrade fuel system with flex fuel capabilities. Definetly wasnt low on fuel.

03-07-2019, 04:33 PM	#7
GHOSST2012 Drives: 2012 Camaro SS Join Date: Apr 2016 Location: Clifton NJ Posts: 162	Stock valve train. No over rev situation but have bounced it off the rev limiter a few times.

03-07-2019, 05:20 PM	#8
stevieturbo Drives: it changes Join Date: Nov 2010 Location: Norn Iron Posts: 1,126	A violent 2 step can be hard on valvetrain. And a new shortblock isnt going to fix valvetrain or bent valves lol.

03-07-2019, 08:11 PM	#9
bayarea408 Drives: T Join Date: Mar 2015 Location: CA Posts: 803	4 bent exhaust valves and only 1 cylinder is down? This shop has some explaining to do. I take it they set the car up and are doing the new 416 as well? Did you break any springs? Where did the tuner set your redline? snap some pictures, this whole thing is vague its annoying.

03-08-2019, 05:55 AM	#11
GHOSST2012 Drives: 2012 Camaro SS Join Date: Apr 2016 Location: Clifton NJ Posts: 162	I have an ls3. The rev limit is set to 6500. I wasnt told which valves were bent and there is no sign of damage anywhere else. They havent taken the pistons out of the block though. Cyl 7 plug was wet with oil on the threads even after putting in a brand new set and checking after about 4miles. Plugs were not damaged at all. After removing the heads cyl7 head port was caked in carbon/oil build up and top of piston was blackened. All other were fine.

03-08-2019, 02:56 PM	#14
hillshooter Drives: 2015 Camaro SS commemorative Join Date: May 2015 Location: Utah Posts: 425	did the timing chain jump a tooth? __________________ 2015 Camaro SS, LS3 Stroker, PRC heads,CUSTOM CAM. AGP 68/68 with custom Hot and Cold side. Fore triple pumps, Holley terminator X. BMR drag suspension with carlyle brake kit. 15" ET drags and 17" skinnies. ZL1 3.73 gears , aluminum driveshaft. TH400 with circle D converter.