CEL 030x misfire codes

Started my Carrera this morning, seemed fine initially but then got a little rough as I was starting to back out of the driveway....flashing CEL came on, so pulled back in and switched cars to go to work. Hooked up the scantool tonight and car initially started w/o CEL but then came back on flashing. P0303 was the initial code, then second scan gave 0300, 0302, 0303. So a quick check of the forums has mentioned coil packs, and bad gas as two possibilities, among others. Coincidentally, the last time I drove the car (Wednesday evening) I DID indeed get gas (Shell 93, at a semi-usual place), but then also had an odd occurrence after I got home - went back outside for something and noticed it was wet underneath the car. Took a closer look, and coolant was dripping down from some place up above on the drivers side - the cylinder 1 -3 side, right? Looked from the top of the engine and couldn't notice an origin of the coolant leak there. The reservoir and surrounding area looked dry. The coolant leak went from a fairly steady drip (off multiple points of the bottom of the engine) to stopping completely in less then 30 minutes. Probably no more then 1/2 cup lost, but probably had to put more then that to get level between min and max after the engine cooled. Could all this be related somehow? My '04 has 85K on it. Never noticed coolant leaking before (in a year of ownership). A fairly thorough Carfax history detail of the previous two owners doesn't mention specifically plugs or coilpacks having been replaced before - unless plugs would fall under "recommended maintenance" (The report does mention separate items like the multiple brake fluid flushed/changes) I probably won't have the time to deal with it myself, so off to the local independent Porsche specialists, probably about 5 miles away. I assume I probably should have it towed?

If your reservoir cracked on the bottom and started leaking, pretty common by 85K, onto your possibly cracked, not uncommon, 85K coils trying to fire plugs with 85k on them. Certainly possible to throw a misfire CEL.

If the cooling system is topped up and as long as it is not gushing coolant you should be ok driving it 5 miles to the shop. This assumes you won't spend 30 minutes in traffic or have to drive 75mph to get there. I've driven several miles with what proved to be a split coolant tank in my Boxster without any harm. Through town but not a gruesome drive. I did wait until the morning commute traffic had died down a bit. (In fact I drove my Boxster a few hundred feet without any coolant in the engine at all after it all came out after I hit some road debris and busted a radiator. The car sat overnight and was dead cold.) Oh, if the during the drive the engine makes any noise out of the ordinary shut it off ASAP and do not restart. Get the coolant tank taken care of it that proves to be the source of the coolant. If the coils are original they are probably due to be replaced. The coolant could have played a role in the misfiring but if the coolant does that then damp weather will too. But have the tech inspect the coils while he's there. If the coils are done I'd replace the plugs too. I do not think reusing plugs in these engines is wise.

This from fpb makes the most sense but Mac, cmon "drive it to the shop". Why? Neither is a hard job and there are tons of DIY's here for both if you determine the above to be the problem.

I was responding to this from the OP: "I probably won't have the time to deal with it myself, so off to the local independent Porsche specialists, probably about 5 miles away. I assume I probably should have it towed?" You want to sell the DIY idea I suggest you speak to the OP.

Yep, I would prefer to DIY, but I think I don't have an open weekend until Oct 12Tth! But regarding driving the car to the shop...I'm not too concerned about the coolant level, but what about driving it with a flashing CEL and misfires? I guess the bottomline- I think AAA covers the tow, so better to be safe then sorry!

Its not your DD so maybe consider doing it when you can?

Missed the flashing CEL. In this case the car should not be driven. The flashing CEL signals the converters are at risk of damage due to unburned fuel reaching them which can cause them to overheat and suffer damage. (The misfires are deemed "rich" misfires by the DME.) The converters are expensive to replace. (Roughly $1000/bank not including labor for my 02 Boxster and that number is probably low for the 996 converters. For a 996 you could be looking at $3K to replace the factory converters with same.)

UPDATE- So did have the car towed to a local Porsche/VW/Audi shop, and the coil packs appeared to be original, so I had them replaced them all, along with plugs and oil changed since it was time for that and it was there, all for about $600. The car does run much better, so that's good. Now on to that coolant leak..... The tech did notice a "weeping water pump". After looking into the details of the pump, it is obvious that the leak I am seeing is not coming from the pump. There may indeed be some damp residue on the bottom of one of the small hoses below the pump, but not enough to drip and not where I have seen the dripping come from - which was farther back near the left rear tire. So I drove the car a few miles to get it up to operating temp and returned to my garage to see what I can see. The main drip appears to be coming off the large plug in the center of the picture below, with a slower drip a few inches to the right of the plug. Obviously the car was too hot to really get under it to see if/where the leak is originating from-presumably from someplace higher up? Whats back in that location that can be leaking coolant? Just the engine block itself?

Wow, your tech noted a "weeping water pump" and didn't assume the bearing is shot and the pump is probably done? Your water pump is due for replacement if it is original, and your coolant tank as well. Your shop can (and should have asked if you wanted them to) pressure-test your cooling system to verify where leaks are coming from. 996 water pumps and coolant tanks fall into two categories: those that have failed and those that are waiting to fail. Replacing the water pump is a couple-hour DIY; the coolant tank can be a bear, so I had that done when I had some other work scheduled. Once the bearing on the water pump is compromised, the shaft begins to wobble, and the blades shear off of the impeller, leaving you with a barely- or non-functional water pump and bits of impeller blade floating around your cooling system.

well, I believe I did have the option to keep it there and have the pump replaced, but he made it sound like it was common and okay to keep an eye on it. And after reading more about it, it does seem like it is something I could tackle....but it seems like it is not the source of the leak that I am seeing.

Yeah, sorry, not trying to be a *****. Yes, weeping at the water pump is common, but it's also an indication that the pump is done. When you have a leak at the pump, it (a) leaks most when the car is running and hot, and (b) can sling coolant, due to the centrifugal force of the shaft, all over nearby components. The abomination siamese mutant hose that connects the water pump to the overflow tank can also leak, and the original spring clamps can let go. How does the temp gauge look? Are you running hot?

Quotes source post: 10808286

My info is that is it ok for a water pump housing to have a bit of dried anti-freeze stain on it. The implication is there can be some seepage of anti-freeze past the seal. However, the techs told me that the size of stain is important. Too large is not ok. The techs would not tell what was an unacceptable size. In the case of my Boxster there was a stain and it did not extend all the way to the edge of the casting, but the pulley/shaft had play and the pump was bad. So my take is the stain should not be very large at all. What I was told was it was never ok to see wetness anywhere at the pump. If the pump has wet coolant coming from it it needs to be replaced. Whether this is the source of the coolant leaks I can't say but it is the source of one. And a leak that indicates the pump is close to mechanical failure as the leaking will almost certainly come with increased bearing play which can allow the impeller blades to contact the block and break the blades.

To OP, I can't guess where precisely your leak is coming from - I'm just pointing out the items in that area that are notorious for coolant leaks. When you get it nailed down, please let us know what the issue was.