2010 SS misfiring after rain/moisture in air

[96SS10SS]

I'm at the dealer now for the second time this week related to misfires...

Background:

June 10 brought heavy rain to the Philly area. When I started the car the morning after the rain, June 11, it began misfiring. I shut it off and restarted it a few times and eventually it set the code and lit the check engine light. It ran ok for a few days but it resurfaced later in the week. I took it in Monday June 17 and they reported a #3 misfire and replaced the plug and wire.

Yesterday morning it rained on my way into work and when I started it at the end of the day, it began misfiring. I made an appointment immediately.

I came out this morning and there was dew on the cars. I started it up and drove to the dealer while it misfired the whole time.

The service guy just came out and said the #3 cylinder is misfiring along with random misfires in the rest of that cylinder bank. They called a technical service line and found out that there are some issues with valve springs but that wouldn't relate to misfires involving moisture. They are going to try swapping coil packs now.

Everything I have found about Camaro misfires relates to either the V6s or Fourth Gens.

Has anybody had moisture related misfiring issues with a bone stock LS3?

[Chevrolet Customer Svc]

Originally Posted by 96SS10SS

I'm at the dealer now for the second time this week related to misfires...

Background:

June 10 brought heavy rain to the Philly area. When I started the car the morning after the rain, June 11, it began misfiring. I shut it off and restarted it a few times and eventually it set the code and lit the check engine light. It ran ok for a few days but it resurfaced later in the week. I took it in Monday June 17 and they reported a #3 misfire and replaced the plug and wire.

Yesterday morning it rained on my way into work and when I started it at the end of the day, it began misfiring. I made an appointment immediately.

I came out this morning and there was dew on the cars. I started it up and drove to the dealer while it misfired the whole time.

The service guy just came out and said the #3 cylinder is misfiring along with random misfires in the rest of that cylinder bank. They called a technical service line and found out that there are some issues with valve springs but that wouldn't relate to misfires involving moisture. They are going to try swapping coil packs now.

Everything I have found about Camaro misfires relates to either the V6s or Fourth Gens.

Has anybody had moisture related misfiring issues with a bone stock LS3?

Hello 96SS10SS,

I am sorry your having misfiring issues with your Camaro. I understand the frustration you must have. You mentioned that you are back at the dealership. I would appreciate an update on the progress made as I would like to make sure this issue is resolved for you. If there is any assist I can lend along the way, be sure to let me know.

Reggie B.
Chevrolet Customer Care

[96SS10SS]

Thank you, Reggie. I will post any results.

[96SS10SS]

I just found this post, http://www.camaro5.com/forums/showthread.php?t=150509, but it doesn't help since mine is a trouble code situation.

To clarify the above: the check engine light has been flashing and the car has been running rough during the misfire periods. I know this is bad for the catalytic converters among other things.

[96SS10SS]

I just received a call from the Service Dept. They tried swapping coils and the problem remained at #3. They opened up the valve cover and found a broken valve spring. They're not sure what role the moisture played in the misfire.

[96SS10SS]

So I am forced to revisit this problem again...

I was driving home from a minor league baseball game in Reading, PA on Friday April 18 and was within about 30-40 minutes of my home when all of my dash lights came on and the engine light started blinking indicating a misfire.

After a while, I had to stop at a red light and it stalled. At one point I received the "power reduced" message. I was only able to chug along at 13 mph in first gear (up a hill no less) so I pulled off the road as soon as I could to get out and pop the hood. Nothing looked amiss so I decided to try to limp home as it was around midnight.

I started it up and it did not have "power reduced" anymore.

I pulled into my neighborhood, shut it down and called a tow truck the next morning.

The car has been in the shop since Monday, where it was scheduled to get new brakes and the 3.91 ring and pinion installed.

So far, I have heard very little from the dealer but it's another broken valve spring and I imagine they are looking for further damage.

I have no confidence in this motor as this is the second time it has been in for a broken valve spring with just under 60,000 miles on it. I'm going to hit the year limit on the powertrain in November 2014 and I'm not confident it won't happen again.

[96SS10SS]

Just picked it up today after a week in the shop...

They replaced the driver side cylinder head and a new intake manifold.

Last time it was the #3 intake valve spring that broke and this time it was a #7 (unspecified) valve spring. The replaced the spring and found a bad lifter during a leakdown test. They decided that the head itself was suspect so they replaced it. When they reassembled it, the car still ran poorly so they pulled the intake and found a melted intake runner in the same area as the broken spring.

This isn't a common problem for stock LS3s from what I've been able to find on here, so I called GM directly to see what gives...