Hey I have this problem when I start my 2000 996 for the first time every day, it will run rough, and you will hear some popping from somewhere. It will go away when the engine warms up. No fault codes. I just changed the spark plugs, no change. I didn't see any cracks in the ignition coils. I have 89k miles and i had the 60k mile service, so I'm assuming they changed the coils. On two different occasions I checked for loose vacuum lines and the weird thing is, after I do that, the problem will not be there the next day or two, then return. I did not find anything obviously wrong with the vacuum lines. I recently had a broken oil fill tube which i replaced. Since I live nowhere near a dealership, I took it to the euro repair shop locally and had them change the oil, and they used amsoil.

I work on it on the weekends, and this weekend I will change the oil to mobil1 5w50 or 15w50 and see if that helps.

My question,

If an ignition coil is bad, will it throw a code?
What else could be wrong?

thanks in advance

 

Hey man. Maybe take a short video of the sounds it's making,might help you get better answers from everyone.

 

Popping sound as in exhaust leak?

 

No its definitely not an exhaust leak because its not rhythmic. ill make a video soon.

 

Cold start issue...possibly something to do with secondary air injection system? The secondary air pump is located to the left of the airbox/oil fill, and runs for a couple of minutes during cold starts.

Try a cold start one day with the engine compartment open and listen carefully to see where the noise appears to be coming from...post results, that data will also help us provide better tips. Good luck.

 

I didn't get any of the popping i was getting in the earlier weeks, but you can hear another...hesitation? jerkiness? stuttering? I don't know what you would call it. But here's a link to my youtube channel, i have 3 videos: inside the car, outside, and around the block. the problem exists under 2500 rpm, usually between 1k and 2k rpm. you can see the camera shaking when it stutters. I have the PSE toggled on and off, i don't know if that helps.



http://www.youtube.com/user/mmddamian?feature=mhee

 

I saw in the video my oil level is higher than the marker on the dash. Think that could be it?

 

My car is cold natured and has to warm up before ir smooths out......????

 

Agree with '996Cab', sounds like a cold start issue but takes some more info to identify.

 

it seems like my cold start air pump isn't kicking on consistently. That and my remote key quit working. The relay and fuse is good for the cold start air pump motor. I shorted the relay for the pump and had it running on a cold start and it ran worse than with it off. Also checked the cold air valve and its switch, both fine. recently i got P1275 (oxygen sensor ageing delay bank 1 below limit value), P0102 (mass air flow sensor below limit value), P1118 (heating power o2s behind cat c. bank 2) codes. cleared them and put in my old maf (thinking maybe the new one has a problem) and then i got p0410 secondary air injection system cyl 1-3, p1411 secondary air injection system cyl 4-6, p0102, p1126 (multiplic mixture adapt lower load range) . I'm going to check the vacuum hoses and tank. do you guys think maybe its the ecu? If so, anyone have a spare i can try?

 

Issues with running straight come down to 3 things:
Air, Fuel, and Spark

Air is rarely a problem. Fuel usually comes down to pump or filter unless it's a weird one.

Sounds like spark. Have you cleaned your MAF and what have you done to the car? Spend $5 on MAF cleaner and either it solves it or you wasted $5 versus 10x that ore more.

 

yes ive cleaned the maf, and i got a new one too. changed the spark plugs, the coils look new (ive had the 60k mile service at around 68k, car now has 89k). new o2 sensors (genuine porsche). After I check the vacuum lines, if i cant get a hold of an ecu to borrow, im gonna have to break down and take it into the stealership.

 

Not necessarily. Even new coils go bad quickly sometimes - it's a turkey shoot. If they are working properly, don't change them. If they aren't, you can experience any number of apparent "other" problems. I used to have the "bucking bronco" problem on start-up as well. After putting up with if for a few months, the coil finally went bad enough to throw a code that told me what cylinder was problematic. Once I replaced - only that one coil, I had a smooth ride again. All the coils were only a few months old when the trouble started.

 

I recently have had a similar problem with my 03 c2 x51... The sound/ rattle would go away over 2000rpm. It ended up being my left side cat... I got a code I forget which one(306) or something like that... It's about 1800-2500 to fix depending on where you go

 

I just listened to your video... Definitely the same problem. My mechanic (very talented) told me to pay attention to it, but it's not a huge deal until you go in for emmisions.