Cmweber

Please Help!!!

I just purchased a 2001 996 a week ago. It ran fine for a few days, then one night I tried to start it up and the CEL started blinking, then solid, then blinking, etc. Since then, the idle is pretty rough, especially with the a/c on.

I put the code reader in, and I got P1130, P0300, P0301, P0302.

The car has 90,000 miles on it, and here is the rest of the story.

1. The night before, it rained pretty hard. It may have been the first time the car has gotten wet in months, as the previous owner kept it under a carport. My concern with wetness revolves around possible coil failure.

2. Also, I performed a oil drain plug swap. When I bought the car, I asked the owner to perform an oil change in my presence, so I could check the filter for particles (IMS). The filter was fine, but the previous owner had to reuse the plug gasket, so the car developed a slight drip from the plug. I ordered a new plug, and simply removed the old one, and shoved the new one in and tightened it. Some oil came out, but it was about 1/4 of a quart, so I replaced that amount of oil with new oil. Also, no more drip.

Any help or ideas would be greatly appreciated.

Cmweber

Also, it appears that the P0301 code was pending, and was able to be cleared by the OBD2.

Hurdigurdiman

Rain or dampness has nothing to do with the way the car is reacting. I know nothing about codes. The thing I would check is when the last time the spark plugs were changed.

(addition here) I would like to retract that first paragraph because of the posting from Macster. Now that is big news to me that a lot of rain would effect the starting of a Porche engine or any other engine for that matter unless the rain was landing directly onto the opened engine lid. I stand corrected and back out of this thread diligently. .

redridge

sounds like cracked coil packs

Cmweber

Does it make sense that coil pack problems would show up after a big rain?

Macster

Well, I'm going to have to disagree with Hurdigurdiman...maybe.

First, my disagreement: I believe leaving the car out in the rain has everything to do with the symptoms.

Two times now I have left my 996 (Turbo) out in the rain (overnight or during a full day of heavy rain) and both times upon cold engine start the engine was rougher than usual and the CEL came on.

P0300 and a couple of other P030X error codes, all misfires.

The coils are original and the car has over 92K miles. The plugs were changed a few K miles back and the Porsche tech reported the coils looked just fine.

I'll tell you what the tech told me the 1st time this happened to me: Clear the codes and drive the car. If the coils are truly bad the symptom will come back.

I went a bit further and several times left the car outside overnight and the misfires never resurfaced until I left the car out in a heavy rain storm this last 'winter' here in the SF bay area.

I will add though a caution and that is if at any time the engine starts to act up, CEL or no, run rough, lumpy idle, make noises, smoke, anything out of the ordinary shut off the engine and do not run it again until you have lined up a pro Porsche tech who will advise you.

I do not expect anything serious is lurking, but better safe than sorry.

Where I could agree with Hurdigurdiman is that P1130 code is a bit troubling. That's O2 sensing adaptation range 2 (cylinders 4-6) enrichment limit.

The #2 bank is running lean and the DME added fuel and added fuel until it reached its, well, enrichment limit.

This can come from an intake air leak, a too low of a fuel pressure (at least on that side of the engine), fuel injectors contaminated, or the fuel supply too low.

That the other bank didn't throw a related error code suggests the problem is not common to both banks which lets out the fuel supply being too low.

However my info is misfires should not be logged if the fuel level is 'too low'. So this kind of lets the fuel supply level cause go by the wayside.

It could just be one bad injector. The DME can only monitor a bank's worth of cylinders by the bank's #1 and #2 O2 sensors so if one injector is contaminated (and not flowing enough fuel) the DME will add fuel to all injectors of that bank. This can lead to rich misfires of the other (healthy) cylinders.

A blinking CEL signals rich misfires, misfires that arise from a condition that can dump raw fuel into the converters which can overheat and ruin the converters.

Thus you may want to get the car to a shop rather than just clearing the codes and driving the car around some more. The extra fuel in the healthy cylinders can contribute to accelerated wear and this fuel can dilute the oil with risk to the engine from this diluted oil.

Added: If you pushed me to name a suspect cylinder, and its suspect injector, I'd have to say "3". The misfires occurred in the #1 and #2 cylinders. These may be the healthy ones and they misfired from too much fuel.

Sincerely,

Macster.

C4CRNA

YES! and also check the area around the battery take off the plastic covering there and look to see that all the rains are free of leaves, dirt acorns etc.

Cmweber

It's funny you should mention the battery. When I give the car gas (in neutral), or turn the a/c compressor on, it almost appears as if the dash lights dim a bit. Not much, but just a bit for a moment.

I don't have much experience with a 911, so I wasn't sure if that was normal or not...

P.S. One other thing... During the heavy rain, the car was sitting in my driveway with the rear spoiler up (in manual), but the hood closed.

Thanks again for all of the help.

Cmweber

The rain stopped last night, so I figured I'd test my theory this morning. I read the codes again, which were:

P1130
P0302
P0301 - Pending

I erased the codes and started up. There was a rough idle, and the CEL started blinking again. Shut it down, read the codes.

Now only 1 code:
P0302 - Pending

Erased codes again...

Started again. Noticed the idle was completely smooth... Waited for the light... It never came on, so I took it around the block (just over a mile). The car ran fine... no CEL...

But, now it's raining again. I may wait for it to get real wet and see if the CEL comes back.

Thoughts?

C4CRNA

The is a voltage meter on the left side of the dash. Watch it! If with the ignition on(but car not started)
you will get the battery voltage should be near 12V
After starting the car you will get the alternator output.
Initially after starting the car it should go to 13.5 or 14V for a while till it gets the battery charged up from the starting drain. Watch this volt meter when the AC goes on and off and when you add lights heater fan etc a little dip in the voltage is the lag before the voltage regulator tells the alternator to charge the system. Could be normal to have a quick dip in voltage or the begining of the voltage regulator failure. You can just change the voltage regulator(but the alternator has to come out)
Or just replace it all(alternator) when it goes.

A little heat from your engine should dry out the coil packs pretty fast.

redridge

Im thinking coil packs... more so, the O rings, they may have cracks on them. I would check that vicinity.

Ericginpa

I'll chime in with coil packs as well.

Cmweber

Just an update

The car was still running fine today. However, I noticed that the coolant is well below the minimum line in the reservoir.

Now I'm concerned I could be dealing with a head gasket leak (or worse). The reservoir is the .03 revision. If I had coolant getting leaking in the engine, is that a situation that would get better on its own? Can that cause the CEL for misfires?

Thanks again... again...

Cmweber

Good point... The CEL was cleared, the light didn't just go away.

One other point... The low coolant light has never come on and the temperature is fine.

Cmweber

So I just brought the car to my local Indy. They are not open today, but they will get to it first thing tomorrow morning.

Once again, it was pouring down rain. The road was very wet and there were many puddles. On the way to the shop, I was in stop and go traffic (literally a red light every few hundred feet for a few miles). 3 or 4 times, when I stopped at a red light, the rpms would drop during idle and the CEL would flash. As I was looking for a place to pull over, the CEL always stopped blinking and the light wen completely out by the time I got to 20 mph.

Does this make sense to anyone?

My thinking is that the P030X codes make sense for misfire if I have bad coil packs getting wet, but my concern is that i do not understand the P1130 code. Additionally, the low coolant has me concerned that it could be related to the P1130 code and possibly be from a more serious problem. I added coolant this morning, and it didn't take very much. I would say the level was 1" below the minimum mark on the expansion tank.

Any thoughts are much appreciated...