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Sudden P0300/P0301/P0302/P0303 codes

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Old 09-29-2017, 08:56 PM
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srmorse
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Default Sudden P0300/P0301/P0302/P0303 codes

Hi all...first off I'm a newbie having just bought a 2000 Carrera Cab last weekend...and drove it back from Alabama to NY with no problems. But today started the car for a store run and as I got about 1/4 mile away the CEL started flashing. Turned right around and parked at home and pulled the codes. Codes were all misfire and appears to affect the entire drivers bank...so other pending or stored codes. Car has driven flawlessly for about 1500 miles in past week with no other symptoms of anything amiss.

I know that often indicates coils...but seems odd all three on one side would happen at once. MAF I suspect would affect both sides (although maybe not). AOS is very recent...guidance on how to whittle down causes and things to test. It's already going to a local shop for check over on Tuesday as well...as I think I may have pinion bearing starting to make noise...frustrated for sure that the first week has been a bit rough other than the 1200 mile drive back which was awesome.

Thanks in advance...look forward to people's thoughts...
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Old 09-29-2017, 10:09 PM
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Chris(MA)
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Does it run rough? tried resetting the codes and see if they come back?
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Old 09-29-2017, 10:58 PM
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Bank 1 (driver's side) has given me misfires. My issue was cracked coils aggravated by a coolant leak.

If you don't have records or an idea of when the coil packs were last replaced, it's a relatively inexpensive option to start troubleshooting. Coils & plugs, then retest. Crank sensor is a cheap replacement that can cause misfires, though having only one bank cause issues seems like something local triggered it while leaving bank 2 ok. The coolant expansion tank is driver's side along with some piping, so that's why I brought that up. I guess mayyyybe fuel pressure sensor or something specific to the bank one fuel rail could cause it to stop detonating, but I'm not familiar with that system yet.
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Old 09-29-2017, 11:09 PM
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Originally Posted by Chris(MA) View Post
Does it run rough? tried resetting the codes and see if they come back?
Yup...it does indeed hesitate, and that is when it starts the flashing CEL. I did reset codes and it does indeed come back. Last night was first time having the car where it got down to around 50 degrees and lots of dew this morning. Codes are same...no other codes beyond the 4 misfires. Have not brought up to full operating temp though today to see if goes away. Did not want to damage cats...
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Old 09-29-2017, 11:11 PM
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Originally Posted by TonyTwoBags View Post
Bank 1 (driver's side) has given me misfires. My issue was cracked coils aggravated by a coolant leak.

If you don't have records or an idea of when the coil packs were last replaced, it's a relatively inexpensive option to start troubleshooting. Coils & plugs, then retest. Crank sensor is a cheap replacement that can cause misfires, though having only one bank cause issues seems like something local triggered it while leaving bank 2 ok. The coolant expansion tank is driver's side along with some piping, so that's why I brought that up. I guess mayyyybe fuel pressure sensor or something specific to the bank one fuel rail could cause it to stop detonating, but I'm not familiar with that system yet.
I do have record of coolant expansion tank being recently replaced and no signs of coolant leak. I have good records on the car but did not see anything for coils since at least 2009...plugs and tubes show to be done in 2011. I've ordered coils and plugs from Pelican and will start there for sure. Likely will pull MAF tomorrow as well and clean. Was also wondering about fuel delivery...but is at low RPMs and came on REALLY suddenly...
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Old 09-29-2017, 11:24 PM
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Sounds like you're on the right track. Bank 2 is where the ugly cylinder stuff happens with the m96 so I'd try not to sweat it too much until you get new coil packs & plugs in. Preexisting or not, these things will happen. Let us know how it goes.
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Old 09-30-2017, 01:19 PM
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Default new pending code 1340

So this morning I was checking for any potential vacuum leaks and bringing car up to temp to see if there was any change in misfire behavior...but also now getting a pending P1340 code. Believe this means cam timing adjustment issues potentially?
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Old 09-30-2017, 02:48 PM
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A couple of suggestions:
1. Ask here for a competent M96 Indie in your area. His diagnostic time could save you $$$$
2.Get Durametric to know the details of the fault codes.
If you suspect some coils - replace them all.
But be prepared for 'while you are in there' issues like spark plug tubes+O rings + plugs.There ar lots of other things to observe/check.
Read a lot on the M96 .Don't think it is just another car engine. It will bite you. Think of it as a helicopter engine and be prepared for lots of learning.Then see 1. above - often cheaper in the end.
Oh and one word to be wary of "Deviation" -see 2. above.
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Old 09-30-2017, 04:18 PM
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Originally Posted by Schnell Gelb View Post
A couple of suggestions:
1. Ask here for a competent M96 Indie in your area. His diagnostic time could save you $$$$
2.Get Durametric to know the details of the fault codes.
If you suspect some coils - replace them all.
But be prepared for 'while you are in there' issues like spark plug tubes+O rings + plugs.There ar lots of other things to observe/check.
Read a lot on the M96 .Don't think it is just another car engine. It will bite you. Think of it as a helicopter engine and be prepared for lots of learning.Then see 1. above - often cheaper in the end.
Oh and one word to be wary of "Deviation" -see 2. above.
Excellent point on finding a good indie...I have been referred to R&D Automotive in Albany...but I would like to hear from folks in the Albany, NY area on any references. I did order coils and plugs as well as cam position sensor from Pelican. I see in records a recent plug tube and o ring change...but nothing on coils...so to rule those out I will replace all as well as plugs. Seems odd that three may go at once and on one bank...so with the pending P1340 I thought the cam position sensor was a good step to try as well and even if not the culprit at least I will have a just in case spare...
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Old 09-30-2017, 04:56 PM
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CAM sensor ? Do you mean CRANKSHAFT ? The Cam sensor seldom seems to fail. The Crankshaft Position Sensor is a more likely culprit to fail when hot.It is very difficult to r&r the CAM sensor unless you also r&r the AOS ,which is also awful - but your Indie knows all this ! Check for oil in the spark plug tubes anyway.
Misfire codes on just one Bank - Vacuum leak there? Are the Lifters ticking on that Bank?

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Old 09-30-2017, 08:27 PM
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Originally Posted by srmorse View Post
Excellent point on finding a good indie...I have been referred to R&D Automotive in Albany...but I would like to hear from folks in the Albany, NY area on any references. I did order coils and plugs as well as cam position sensor from Pelican. I see in records a recent plug tube and o ring change...but nothing on coils...so to rule those out I will replace all as well as plugs. Seems odd that three may go at once and on one bank...so with the pending P1340 I thought the cam position sensor was a good step to try as well and even if not the culprit at least I will have a just in case spare...
Once you get into misfires that prevent normal operation I think you're best served by stopping driving & waiting until you expect it to be ok (ex. after new plugs & coil packs are installed). Seeing cam deviation is not good and further reinforces the ECU's message that something is off mechanically. I would stop driving at all & flatbed it to the garage that can properly fix it. AAA is a good resource to have.
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Old 09-30-2017, 09:18 PM
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Yes, forget about coils and MAF, you have a mechanical issue in bank 1. Camshaft timing is off too much and you need a Durametric to diagnose it further. Physical inspection of cam timing is also needed. Should try not to drive it again to avoid damage.
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Old 10-01-2017, 01:26 PM
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Originally Posted by srmorse View Post
So this morning I was checking for any potential vacuum leaks and bringing car up to temp to see if there was any change in misfire behavior...but also now getting a pending P1340 code. Believe this means cam timing adjustment issues potentially?
Didn't have the misfires but I had the P134(1) code (pending) from my 2002 Boxster when its engine was behaving like the engine in your car.

Turned off the engine and upon restart all was well and drove it 30 miles home. Next business day got the car in the Porsche service department and tech diagnosed the problem as a VarioCam solenoid/actuator failure (with the Boxster engine one can't distinguish between the two when it comes to not working right) and both were replaced. Asked tech about the other bank's solenoid/actuator should they require replacement and he said no error codes, no symptoms, no signs of any problems, not they do not need to be replaced so they were left alone.

60K+ miles later engine still running just fine. Other bank's solenoid/actuator is original and has covered over 315K miles.

While my Boxster engine didn't misfire I observed the fuel trims were all over the map. Mentioned this to the Porsche tech when I dropped off the car and he said this is normal. It arises because the cam is not positioned where it would be -- advanced or retarded as it should be -- the oxygen sensor readings on that bank are wrong. The DME adjusts fueling to try to get the desired oxygen sensor readings but because the problem is a mechanical failure readings will not hit the desired targets and the DME will eventually adjust the fueling too far and misfires are the result.

Best to arrange to flat bed the car to a qualified shop for a professional's diagnosis and repair.
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Old 10-01-2017, 05:14 PM
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There are simple tests on Renntech to verify the Solenoid resistance and the integrity of the solenoid wiring harness. These tests are not intrusive but they are time consuming and demand a methodical approach.
Before you dismiss it, just price a replacement Actuator !The solenoids are comparatively cheap at about $500 ! And then there is the R&R
If you want help with Actuator/Solenoid testing and R&R , probably better to start a separate thread ? It is not for the feint of heart
https://www.renntech.org/forums/tuto...d-swap-in-car/
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Old 10-01-2017, 06:57 PM
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Thank you all very much for helping out here....I'm already learning a lot. I am a long time car guy and have a pretty sizable background in working on my own cars, but I also know that this is significantly more complicated and the penalty for taking the wrong step could be very pricey. I already have an appointment with R&D Automotive on Tuesday...they were going to look over the car after my purchase...but I'm going to call them tomorrow and see if I should wait until after I put in the new coils (those won't arrive until Thursday), or load it in the trailer and bring it down to them on Tuesday anyways.

I'm definitely not driving it...I have however started it a couple times. I did find a vacuum leak...on the drivers bank at the intake manifold vacuum port (part #99611015152). It was wobbling and shooting a little MAF cleaner at it when idling raised rpms a hair. Also it is much warmer today (around 65) and I stated the car in garage...still a hair rough on idle...but no codes after letting it idle from cold idle to warm idle.

Will keep folks posted as II'm hoping that whatever it is I'll be able to help others down the road...but may be delayed a few days depending on shop visit, coils etc...and while I don't think coils, plugs and the replacement vacuum port will fix it...they are items that need to be replaced anyway for peace of mind and help isolate the root of the true problem!
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