need help diagnosing codes, p0300 etc - 986 Forum - The Community for Porsche Boxster & Cayman Owners

juicepro · 08-17-2011, 02:56 PM

hello, i could use some help. i just pulled the following codes p0300, p301, 302, 304, 305. i know this means random misfire, whats my next step?

copsahl · 08-18-2011, 07:22 PM

What were the symptoms leading up to the CEL?

juicepro · 08-19-2011, 04:25 PM

just bought the car last week so i don't know the symptoms leading up to it. i only realized when driving above 5,200rpm(cel light flashes) so far i've checked for a vacuum leak, cleaned MAF and switched the coils around but still the same codes. i'm going to try changing out the sparks plugs and go from there, any suggestions please?

Johnny Danger · 08-20-2011, 04:29 AM

Quote:

Originally Posted by juicepro

hello, i could use some help. i just pulled the following codes p0300, p301, 302, 304, 305. i know this means random misfire, whats my next step?

You may find this link valuable .

http://boxster.wikia.com/wiki/CEL_Error_Codes

copsahl · 08-20-2011, 02:37 PM

If the faults are only at higher RPMs, I'd guess the misfires have to do with valves/valve timing. But, others on the forum may have a better idea.

juicepro · 08-20-2011, 05:48 PM

it doesn't look like this car has been serviced for a few years, i've ordered an air filter and plugs we'll see if that changes anything. thanks

Paul · 08-21-2011, 06:37 AM

Are you "feeling" the misfires?

juicepro · 08-21-2011, 03:06 PM

"Are you "feeling" the misfires?"
No, the car seems to feel and drive fine, but i only just got it last week so it's hard for me to have a baseline "feel" for this car.

Paul · 08-21-2011, 03:41 PM

I agree, let's see what new plugs do.

juicepro · 08-23-2011, 05:00 PM

just changed the plugs and now it's running worse than before, maybe the MAF?

mikefocke · 08-24-2011, 02:36 AM

What was its history before you bought it? Do you have a great local Porsche mechanic available (Someone with a PWIS or PSTII and the knowledge to use it)?

A flashing CRL light says "very serious...don't drive...you risk blowing the engine". Get professional help.

juicepro · 08-24-2011, 05:33 AM

sorry mike, i don't know much about the vehicle apart from it having 3 owners, the last owner had it for 3 years (30k) and never serviced it.
i was going to try and disconnect the MAF and see if it runs any better. if that doesn't work getting it towed to Fresno Porsche(60 miles away) is my last option. thanks for all the help guys! i'll keep you posted.

juicepro · 08-24-2011, 03:54 PM

just an update. car is running better today, back to throwing flashing CEL only above 5,200rpm. still planning to get it looked over by dealership but hoping to drive it there instead of tow. i'll cruse around town for a few days to see how it feels first.
i can rule out air filter, sparks plugs, MAF and coils.

juicepro · 08-30-2011, 07:34 PM

Hi guys, i got some bad news today. The dealership called and said i have vibration coming from the engine that is likely a failing IMS and that i would need an engine rebuild. The car is a 02 boxster 69k that i bought recently for $12k. I'm stuck and don't know what to do, any suggestions?

Topless · 08-30-2011, 07:50 PM

Quote:

Originally Posted by juicepro

Hi guys, i got some bad news today. The dealership called and said i have vibration coming from the engine that is likely a failing IMS and that i would need an engine rebuild. The car is a 02 boxster 69k that i bought recently for $12k. I'm stuck and don't know what to do, any suggestions?

Your options are to fix it or sell it as a dead roller for maybe $5K. Get a second opinion from a qualified Porsche indy who knows their stuff. If the IMS has not failed yet the motor can probably be saved. TRG is in Petaluma Ca, 911 Design in Montclair, Tony Callas in Torrance. All are excellent. Where exactly do you live?

juicepro · 08-31-2011, 05:25 AM

i'm going to start calling some independent porsche shops today, i live in the central valley but will probably have to get it towed to the bay area.
the car still drives, does this mean my motor is still ok?

san rensho · 08-31-2011, 06:52 AM

If the IMSB has not failed, then its possible to save the motor with an IMSB replacement, $1500-2500 is the going rate. The dealer usually will not replace IMSB, they want to sell you an entire motor.

DO NOT DRIVE OR START THE CAR and take it to an independant who can verify the IMSB diagnosis. One thing you can do is look at the oil filter for ferrous metal and drop the sump plate to look for pieces of the IMSB to verify the diagnosuis.