'08 Redline, misfiring and backfiring

[RagtopGuyinTX]

I've got a '08 Redline that intermittently that will misfire but not set a check engine lamp and will also intermittently backfire thru the intake or the exhaust.

Does anybody else's car do this? I've had it to the dealer more times than I care to talk about and they claim they can not duplicate it and these cars have a rough idle normally. I've searched the forums but nothing really pertains to the '08's.

The car has 10k on it, this started when it had 5K

[Bogie]

Originally Posted by RagtopGuyinTX

I've got a '08 Redline that intermittently that will misfire but not set a check engine lamp and will also intermittently backfire thru the intake or the exhaust.

Does anybody else's car do this? I've had it to the dealer more times than I care to talk about and they claim they can not duplicate it and these cars have a rough idle normally. I've searched the forums but nothing really pertains to the '08's.

The car has 10k on it, this started when it had 5K

The dealer claims a rough idle? Mine idles very smooth.

What kind of gas are you using, and where is it purchased?

[RagtopGuyinTX]

Originally Posted by Bogie

The dealer claims a rough idle? Mine idles very smooth.

What kind of gas are you using, and where is it purchased?

I've tried Chevron, Shell, Texaco, Costco, and Valero. Mostly 93 octane, a couple tanks of 89. It does not seem care. I had previously read about that and tried to eliminate this factor.

It did set a misfire check engine lamp once, the dealer explained "your spark plugs are broken" and they installed new ones. The car ran excellent when we picked it up, nice smooth idle, the car ran better than when we first picked it up. After a couple hundred miles the car soon began running like it had before but fails to turn on the check engine lamp.

[mbeardsley]

I don't know why they would say you should have a rough idle...mine sure doesn't.

Have you tried a different dealership ?

[willis]

I also have a 08 RL. Mine idles very nice. At what RPM do you have a miss?

[Skip]

Originally Posted by RagtopGuyinTX

I've tried Chevron, Shell, Texaco, Costco, and Valero. Mostly 93 octane, a couple tanks of 89. It does not seem care. I had previously read about that and tried to eliminate this factor.

It did set a misfire check engine lamp once, the dealer explained "your spark plugs are broken" and they installed new ones. The car ran excellent when we picked it up, nice smooth idle, the car ran better than when we first picked it up. After a couple hundred miles the car soon began running like it had before but fails to turn on the check engine lamp.

Iffen you can take it to another dealership please do. If not check your plugs and make sure they are the right ones for the Sky you have. And there are numerous threads about the plugs. Search sparkplugs and you will see the current number....Skip...

[Celt03]

A possible scenario is ...
something as simple as a plug wire not seating itself properly on the plug ... believe me when I say that can be a real PITA to figure out.
And what you describe sounds like it.
Can be caused by not being put on correctly or could be caused by a bad wire.
And that can cause plugs to go bad prematurely.
The plugs & wires are pulled and checked but then the wire will work its way looser & looser - causing rough idle, loss of power, etc.

[RagtopGuyinTX]

Originally Posted by mbeardsley

I don't know why they would say you should have a rough idle...mine sure doesn't.

Have you tried a different dealership ?

Saturn of Temple is 1.25 hrs north
Saturn of San Antonio is 2 hrs south

Saturn of Austin, where the car was purchased is about half an hour away. They have had the car 4 times now for the same issue and "can not duplicate it". I'm reluctant to tie up half a day taking it somewhere else only for them to tell me the same thing.

[RagtopGuyinTX]

Originally Posted by willis

I also have a 08 RL. Mine idles very nice. At what RPM do you have a miss?

It always has somewhat of a rough idle, the misfire I've noticed usually happens when I come off of a highway, come to a stop light and it is there in traffic for 30-45 seconds, idling. One cylinder will miss 3 or 4 time in a row then work, then miss once or twice more, by this time the light has changed and I'm driving off. After this it usually doesn't come back until I've been on the highway again.

[RagtopGuyinTX]

Originally Posted by Skip

Iffen you can take it to another dealership please do. If not check your plugs and make sure they are the right ones for the Sky you have. And there are numerous threads about the plugs. Search sparkplugs and you will see the current number....Skip...

I made a promise to myself when I purchased this car never to work on it so I really don't know what plugs they put in it. The service manager explained there was a TSB out about it and they installed "hotter plugs" I really didn't have the patience to explain to him that the TSB was for certain '07's and after a specific serial number the cars were built with the correct plugs.

Oh, by the way, I borrowed the line in your signature the other day about learning to dance in the rain.....Thanks! It made somebody stop for a while and think about things.

[RagtopGuyinTX]

Originally Posted by Celt03

A possible scenario is ...
something as simple as a plug wire not seating itself properly on the plug ... believe me when I say that can be a real PITA to figure out.
And what you describe sounds like it.
Can be caused by not being put on correctly or could be caused by a bad wire.
And that can cause plugs to go bad prematurely.
The plugs & wires are pulled and checked but then the wire will work its way looser & looser - causing rough idle, loss of power, etc.

I could only wish it was this simple, they have had it since 3/31 and have only picked it up last night. They claim to have driven it extensively, put 30 miles on it, and have checked "everything twice"

[Bogie]

Originally Posted by RagtopGuyinTX

It did set a misfire check engine lamp once, the dealer explained "your spark plugs are broken" and they installed new ones. The car ran excellent when we picked it up, nice smooth idle, the car ran better than when we first picked it up. After a couple hundred miles the car soon began running like it had before but fails to turn on the check engine lamp.

Sounds like the plugs may be a symptom of a larger problem.

[Celt03]

Actually - I have seen this very thing happen twice. Both vehicles were new - both went in & out of the dealership's shops a number of times. The first one - the problem was NOT discovered by the dealerships but by an acquantaince of the owner.
The 2nd one - was discovered by my hubby because he had witnessed the first one.
Both were caused by a manufacturing defect in a plug wire that caused it to not seat correctly & slowly work thier way loose. The rough idle & misfiring would then ruin the plugs - resulting in the vehicle running worse & worse.
One vehicle was a Ford & the other was a Chevy.

And the check engine light never came on with either of them.
Put new sets of plug wires with new plugs - problem was solved..

[Darkwing]

Celt I think you have a very valid point. If the problem gets worse as the car warms up the 'rubber'/neoprene/plastic parts get softer..metal expands... well worth looking into. Even though these are 'coil over' setups that don't use conventional type plug wires, there still can be a problem with the individual coil or the wiring dealing with temperature or humidity extremes.

[RagtopGuyinTX]

Originally Posted by Bogie

Sounds like the plugs may be a symptom of a larger problem.

I think when they installed the plugs they cleared the codes, maybe the ECM had to relearn some of the engine sensors and that is why the issue came back in the next couple of hundred miles.

[RagtopGuyinTX]

Originally Posted by Celt03

Actually - I have seen this very thing happen twice. Both vehicles were new - both went in & out of the dealership's shops a number of times. The first one - the problem was NOT discovered by the dealerships but by an acquantaince of the owner.
The 2nd one - was discovered by my hubby because he had witnessed the first one.
Both were caused by a manufacturing defect in a plug wire that caused it to not seat correctly & slowly work thier way loose. The rough idle & misfiring would then ruin the plugs - resulting in the vehicle running worse & worse.
One vehicle was a Ford & the other was a Chevy.

And the check engine light never came on with either of them.
Put new sets of plug wires with new plugs - problem was solved..

Next time I go to the dealership, I'll mention it and see if by chance they missed it. Thank You!

[compdoc777]

I build and work on motors a little more advanced than the Ecotecs so let me put my two cents in here.

That scenario does not make sense in this motor. Yes there is a problem, and no plug wires is not it. These cars have coil packs not plug wires. If one was loose it would have been removed and re-inserted into the shaft and thus solved the problem, but the only problem with that is these coil packs are bolted down to the motor. So getting loose would not happen.

Depending if it is just one spark plug that is being affected then you may have a bad coil pack or igniter same thing. Each cylinder is an individual igniter or coil pack.

Now you may be facing something different could be a wiring problem from the ECU to the engine causing the it to misfire by grounding out to the body somewhere on the chassis and this is very hard to find. As I am going through a simular problem at the moment.

It could be caused by improper fuel from an injector or wiring to that injector or even a valve related issue.

I would suggest you take it to a dealer that will put a little more effort into the problem like that, because yes it is a symptom of a bigger problem and one that can cause a serious failure.

Also call and report the dealer that told you that the spark plus was bad and idling rough is normal to Saturn Corporate.

[Celt03]

The plug wire defect was in the area of how the plug & wire seated together.
Point is - any part can be defective.
And often it is the simple (& inexpensive) things that cause some of the biggest problems.
We have learned - check the simple things FIRST.

Another scenario - a minute crack in the ECM that is not visible to the eye could also cause this type of problem.
We know of a case that it took almost 6 months to track that problem down. The heat causes the crack to expand & run rougher - cooled down - still rough. Eventually - crack will become larger & larger - then the car will begin to stall.

[cfjara]

Originally Posted by compdoc777

It could be caused by improper fuel from an injector or wiring to that injector or even a valve related issue.

Yep i wouldn't rule out the fuel pump.

[Red Sky at Night]

I just posted a thread on the Technical Discussion forum. Check your injectors. I had the same symptoms and new injectors from GM Engineering corrected the problem. Next time you take it for service tell them your problem and have them check your VIN number.