2008 Sebring 2.7l Check Engine *long read*

[RamFan]

Hey guys,
yesterday I made an attempt at changing the spark plugs on my mom's '08 Chrysler Sebring with the 2.7l V6. The front three are easy as could be, simply take off the engine cover and there they are just sitting there. The back three are a different story, in order to get to them you need to take off the intake manifold, that was the problem I encountered. All bolts were removed everything disconnected and the thing wouldn't budge, I heard it creek twice so I stopped. Not my car, not going to be responsible for any damage. I showed my mom why I was stopping and she agreed, I took off the coil on one of the front plugs to show her how unbelievable easy they are to get to compared to the rear. I bolted the intake manifold back on and connected everything again. Turned her on and took her for a one mile drive around the neighborhood to make sure that nothing went wrong (even though the only thing I really touched was the coil on the one plug), sure enough nothing did.

Later that night I went to pick something up from the store and something told me to take her car for some reason. I get in turn her on and let her idle for about 2 minutes as I counted out my change

then bam, check engine light chimes on. Now, the engine sounds the same, has a little rough idle but this car has had off and on rough idles since she bought it. So I drive it for a 5 mile trip and it stays on. I go to work this morning and I take her car instead of the truck to see if I can notice anything, and nothing the light is still on but the engine sounds the same and it runs the same.

Apparently she has had the check engine light come on before, so she took it to a shop and said it was one of the spark plugs, but rather then replacing it they just swapped the plugs around and the light went off. Makes absolutely no sense to me how this would make a difference but apparently it did. I need to add that before I took it out after bolting everything back in I added a bottle of Prestone Complete Fuel System Cleaner (she lives in GTMO and the fuel is suspect as to who its supplied from. So here are my questions. Knowing that fuel system cleaners can mess with 02 sensors, how likely is it that the cleaner is responsible for this? If that isn't likely, what about what I did could have caused this, simply removing the coil? I'm at a loss ideas, obviously it is one of those two options but I can't figure it out.

An appointment has been made to have the plugs replaced.

Thanks

 

[RamFan]

What makes me think or at least hope its the cleaner is that the light didn't pop on immediately, but rather after a one mile trip then after a two minute idle. This makes me assume that the cleaner didn't get into the system right away. If it was the plug coil wouldn't the check engine light have come on immediately?

 

[taylo]

Take the vehicle to Autozone and have them pull the code. That should get you going in the right direction as to what could have happened.

 

[RamFan]

Originally Posted By: taylo
Take the vehicle to Autozone and have them pull the code. That should get you going in the right direction as to what could have happened.


Car is in Guantanamo Bay. Thus, no Autozone.

 

[sciphi]

Does she know anybody with a code reader who could pull the code for her? I know, you're probably down there visiting, and the code reader was the last thing on your mind.

 

[RamFan]

Originally Posted By: sciphi
Does she know anybody with a code reader who could pull the code for her? I know, you're probably down there visiting, and the code reader was the last thing on your mind.


Funny thing is I've got a Superchips Flashpaq for the Ram so I looked up online real quick if it would work for the Sebring and of course it does not. The local Autoport has one, but I'm not sure if you are familiar with NEX Autoports but they aren't exactly vehicle experts and the instrument you need always seems to be down or it never detects a problem. Of course though I will have them do a quick scan regardless whenever I bring it in just to double check.

Yes I'm here visiting during a break from school.

 

[JustinH]

Sounds like it needs new plugs in the rear. Next time you go to take out plugs that have been in for a while, try some PB blaster in the plug holes, then a breaker bar, real easy with it.

If you took the entire intake manifold off, you could have just replaced those plugs instead of leaving them.

 

[finalyzd]

I would try and take that manifold off, replace plugs and go from there

 

[goodtimes]

There are original hard copy service manuals on ebay, may be worth it to get a set. For my Chrysler TC van it tells exactly the steps how to do the rear plugs, doesn't involve taking off the manifold. Just my suggestion anyway, if you are going to work on the car. Another possibility is there is an air leak from the work on the manifold?

 

[RamFan]

So I drove to work this morning (took the car instead of my truck), car sat for three hour, then went to lunch and back home to eat it about 5-6 miles. The car was off for 15-20 minutes while I ate lunch went back out to return to work and the car started with no engine light, the light remains off 4 miles later. This is confusing me more and more.

All the plugs are original, I didn't replace the front ones. If I replaced them and told the shop to do just the rears there is a [censored] good shot that they would mess up that request some how. The mechanics are Filipinos and we have major language barriers when trying to describe a problem to them. Great guys and hard workers but their English skills are lacking. The car only has 16k miles on it any how so the fact that I even need to replace one of them is kind of annoying.

I intent to buy a Chilton manual for it I just haven't gotten around to it yet. Unfortunately I'm 99% positive that the entire intake manifold has to come off, if not I will be greatly surprised, the manifold completely covers the back end of the engine. I have just enough room to touch one of the coils with the tip of my fingers let alone some how fitting in the tools.

As previously said it still runs fine, well like it did from the factory, that doesn't necessarily mean fine lol. I'm not terribly concerned, once the plugs are replaced and this tank of gas is used if the problem still persists then I'll begin being concerned. Any ideas in the mean time?

 

[The_Jeff]

Do you have access to a base "car hobby shop"? Do they have a scanner?

Misfire diagnostics often require the car warmed up and or the throttle above idle. But dead misses make the CEL flash. I'd get the code.

Do you think availability of plugs is what made them swap them around? It's actually a good diagnostic, if the misfire follows the plug (and you can confirm with the scantool) you know the plug is bad.

 

[RamFan]

Originally Posted By: eljefino
Do you have access to a base "car hobby shop"? Do they have a scanner?

Misfire diagnostics often require the car warmed up and or the throttle above idle. But dead misses make the CEL flash. I'd get the code.

Do you think availability of plugs is what made them swap them around? It's actually a good diagnostic, if the misfire follows the plug (and you can confirm with the scantool) you know the plug is bad.


Yes we have a hobby shop but they don't have a scanner. Good point about swapping the plugs to see if the misfire follows, but in this case the misfire didn't follow so what would that mean? A bad coil perhaps?

 

[sciphi]

Bad coil is a possibility. Can you swap the coil around? If that causes the misfire, it's time for a new coil.

 

[2002 Maxima SE]

Removing the IM to get to the rear plugs is standard these days. Both my Maxima and my Taurus wagon require it (though with the Taurus, you can remove the windshield cowling and get them that way as well).