So today I changed my valve cover gaskets (left and right, used the 2004 cover) and changed all 6 plugs. I did not buy new coils or boots, simply re-used the old ones. I did use a bit of dielectric grease and ensured that the boots were firmly over the new plugs. Now the car barely runs, it stalls unless I step on the gas, and it sputters even doing that. Sounds like it may be misfiring but no CEL yet. Anyone experience anything similar? I am thinking I may have disturbed one of the electrical connections, although I was careful to put everything back where it was. I also was gentle removing the coils and boots, but maybe I disturbed them. Are there any other solutions? I have read that the symptoms sound like they could be the IACV or the MAF sensor, but I did not change either of them, I don't think I even touched them. So many things are connected/disconnected in this process, it's tough to pinpoint what may have gone wrong. Any ideas? Thanks in advance.

 

You need to hook up your vehicle to OBD II scanner to check for error code and impending error code. Did you clean the throttle body and move the butterfly?. You need to do the throttle relearning procedure.

 

I haven't done the OBD II, I guess I will try to run it until it throws a code. I'm pretty sure it will eventually.

 

So chances are you might have goof up on the intake manifold gaskets or forgot a vacuum hose considering that all has to come off to get to the rear valve cover and plugs (guessing 3.5 since you did 2004 valve covers). Sounds like you have one knarly vacuum leak.

Suggest you re-verify you got everything back together properly.

S

 

I also did not clean the throttle body. Didn't want to disturb anything unnecessary.

 

Still going to say vacuum leak.

 

Yes, it's a 3.5 2002. I will verify them once again, it is quite possible that I missed one. I also bought one new coil and replaced it into each of the six cylinders one by one (very tedious) so I don't think it could be a coil unless 2 or more went bad at once.

 

I don't think it would be coils based on the behavior...unless you forgot to plug the coil packs in all together on the back side.

S

 

Im thinking the little springs inside the boots may not be making contact. Does everyone replace the boots when doing the plugs? I didn't do that, maybe I should have.

 

I'd say I agree with the vacume leak. Check all vacume lines and that they're back in the proper locations. I think even with a boot not making contact you would probably hear it arcing a little. Even if that was the case or if you possibly cracked a plug by overtightening or a bad coil you would definitely have a misfire but the fact you said you had to give it throttle to stop it from stalling would point more toward a vacume leak I would think.

 

It's really hard to mess up coil pack swaps, and I've personally never heard of folks having issue with the contact springs. . I've never heard of anyone having problems with the springs that make contact with the plug. So I really doubt the coil pack change is your problem.

S

 

Out of sheer desperation I decided to change all 6 coils, now the car is back to normal. Thanks colt149, maximase, and ac max92 for your feedback!

 

ah, the old shotgun approach

 

I guessing the replacement of the coils had you re-installing the IM which fixed the vacuum leak...but hey, new coil packs are good!

Glad everything is up and running well.

S

 

Yea, I think you are 100% correct. I too had this problem after changing plugs and the rear valve cover. Car would barely stay running. I decided to take the manifold back off--reinstalled it and everything was good. The intake manifold wasn't sitting properly.

 

I guess I will never know, but I couldn't find anything else out of place so I went with the coils. As long as I'm up and running, it's all good.