Porsche Cayman 987.2 2.9l cylinder 4 misfire

Hey guys, First of I want to apologize for the long post. New owner of a 987.2 base, manual. Black on black and a spec I would pick out myself if I was ordering one. So in a sense a perfect car for me. I bought the car more than half a year ago and I can easily say it has been more impressive than I could ever dream of. However just recently I started having a weird problem. I have a misfire on cilylinder 4. Also the car has a little bit of a rough idle. I just though it's how those engines work, since it's my first Porsche and tbh, I have never even been in one (apart from a brief couple of km ride in the first Cayenne model, which doesn't count). Also twice now, I had smoke on start up. I daily drive the car (it is my dream car, so I decided I will just drive it regardless of the km/miles I put on it) and it never smoked. For 8.5k kms I had to put in less than a liter of oil, which everybody says, it's perfectly normal. Never had an error for oil or anything, I just have the habit of checking it and if it drops to the middle I just add some. Even now after all the cold starts and etc, it has happened only twice. Rest of the time 0 smoke on start up. I changed all the spark plugs and the coil on cylinder 4. Oddly enough the car ran better for like 200 km, but then it threw the error again and now we are back to the rough idle. When the misfire happens I get a yellow check engine light that just disappears after couple of seconds and then we are back to normal. I read, a solenoid could be the culprit, however I can't find any part numbers and also I don't want to throw parts at it without getting some information first. If you got to the end thank you so much for your time and I hope somebody had a similar issue and can help me out with some information.

Sounds to me like an ignition ( spark plug ) coil is failing. I replace the #2 cylinder coil on my 09 987.2 last weekend (83K miles) because of the check engine light, reduced power warning and stumble. Sound like yours is getting ready to die.

Have you inspected all of the coils for cracks? Usually once one starts to go, the rest are not far behind. I replaced all 6 at one go because after many years and heat cycles, I prefer not to have to worry about them failing individually. also do you have a code reader handy to read the codes?

Hey, Thank you all for the suggestions. I don't have a code reader at hand, but when we did scan it, it had a cylinder 4 misfire error. Saddly I don't know the code. Maybe I will try changing all the coil packs before looking into the solenoids. Still not sure to be honest.

I suggest checking them first… see what mine looked like - small fine cracks (not on all 2-3 only if i recall correctly). https://www.planet-9.com/posts/2161576/

FWIW, mine had no visible cracks or defects (other than it wouldn't work).

@StreetBl8s It wasn't clear how you got the code or what the actual code was. It sounded like you replaced ALL 6 plugs but only cyl #4 coli pack. Not to disparage your ability, but are you sure you replaced #4 pack and got the plug correctly torqued? It is a tough one to get a socket on, especially a torque wrench. I've also found some confusing info on google's AI Overview which was wrong. So I've included a previously posted graphic of the 987 cylinder layout

As I recall my code was P0302 "Cylinder 2 Misfire Detected," which illuminated the Check Engine light. I also got a “Reduced Power” warning on the Tach display. Yours should have been P0304 What "solenoids" are you referring to? If the VarioCam solenoids, I can't see how a solenoid failure would throw a misfire code.

Sorry - this will be a bit long, I've quoted everyone so far because I have a few comments/suggestions on each post: I snipped much of the post - since it was sort of a brain-dump single paragraph. "Better questions get better answers" - me. Please read: https://www.planet-9.com/threads/before-posting-a-technical-question-read-this.253613/ I'll try to summarize what you posted: - You've owned a 987.2 for about 6 months and it's been WONDERFUL! - It recently became less wonderful when it started throwing a CEL (Check-Engine-LIght).. and idling a bit rough - Once in a while it blows a puff of smoke on startup, but it doesn't seem to be consuming much oil - You read a code somehow indicating a misfire on cylinder 4 - but we don't have the exact code handy or what it was read with - You don't have a Porsche specific code reader so you tried throwing parts at it hoping to fix it (#4 coil) - but have thought better of that technique and came here for help I think that's it. I'll address each of these: - Damn right - these are wonderful cars - when running correctly. You have the 2.9L engine, an engine noted for being reliable and pretty much bulletproof with a minimum of care. - Well - that means something is wrong. The CEL comes and goes - which is interesting. Is there a pattern to this? I suspect there is - it comes as the engine is warming up, then with some driving it might go out. - The puff of smoke is "normal" - all horizontally opposed engines that don't have 'pinned rings' will do this once in a while when all the ring gaps line up, and some oil leaks past them into the cylinder. On startup that oil is burned off - it's a tiny amount of oil and not worth worrying about unless it becomes persistant and does it on every startup. - We really don't know what the ECU thinks is wrong. A common OBD-II code reader is of very limited value on a Porsche. It only tells the error codes involving emissions, and it's limited in what it can tell you. What you need is a PORSCHE SPECIFIC code reader - it reads the information the ECU is storing away about what's happening. - I'd suggest going to our diagnostics forum and looking at what's around for your car. One that a lot of us use are the Foxwell tools. With the Porsche specific software you're into it for less than $200, which pays for about 40 minutes of labor (or less) at a Porsche dealer, and maybe 60 minutes at an independent. You will find lots of uses for the tool once you have it. It's my suggested first tool purchase I'd suggest for a Porsche owners. OK - we'll continue down the other messages.. With the limited information we have - a bad coil is a good first "guess" - but it is a guess, we don't have info allowing for a definitive answer. He has already replaced the coil that matches the cylinder he's getting the OBD-II error code on. I don't think he's done either of these things - and both are useful. I agree on replacing all of them at once. It's Eilenberger's Law of Parallelism.." (see my sig for the laws). When one fails, it's identical twin (or in this case quad couplets) aren't far behind. Not unreasonable. Since you changed one coil - that doesn't mean that another one hasn't failed.. but we DO need that Porsche specific code reader, and it's lots cheaper than a set of coils.. Yup. That's what they do, but since you've gone to the trouble of removing them, to me it makes sense - just replace ALL of them. The work is a PITA. Money is fairly easy. That happens also. Code reader will help turn that up.. Good info to have. I keep a copy of that in my glove box (I'm strange that way..) Since this engine is installed backwards compared to a 911 engine, even skilled mechanics have been known to get the cylinder numbering wrong. We don't know that yet - we need the codes from the ECU that Porsche hides there. I suspect as "solenoid" - we're referring to a fuel injector. The VarioCam+ solenoids would toss errors on one complete bank of the engine (1-4, or 5-8) OK - so what do we do next? We need to do a bit of looking at values with the Porsche code reader. I'd be looking at: Misfires - are there misfires on all the cylinders, one bank of cylinders, or just specific (one or more) cylinders? Cam timing - desired and actual. A worn timiing chain can result in these not matching. These should be within a degree or two of each other. If they're not there is something wrong, variocam adjuster, control solenoid, timing chain. What are these values O2 sensor valuies and switching pattern for before cat and after cat Fuel trim - should be close to zero again. The last item - fuel trim is what I'd be looking at first. If the CEL pattern is as I described, on with a cold engine, going out when the engine warms up - there are several things this might be: Leaking injector - one that dribbles fuel into the cylinder when the engine is off - then you have an extra-rich mixture on cold start causing the CEL that goes out when the engine warms up A failing catalytic converter - the cats don't work well cold, so the engine is made to run rich on cold startup to "fire off" the cats (get them up to temperature where they work). I'd be looking at the O2 sensors before and after the cat. The before should show a switching pattern as the mixture is adjusted from rich to lean cylinder by cylinder. The after should show a flat-line meaning the rich exhaust gas has been processed correctly by the cat coverter - giving straight line output. If ANY switching pattern shows on the after O2 sensor - you have a cat converter that isn't working correctly. Possibly failing SO - that's my initial thoughts. If you can find someone with a Porsche tool, or even better a Porsche PIWIS - which can do guided diagnostics - you'll know enough to come back to us with "better questons" and we might be able to give "better answers.." We really need the Porsche codes and a few numbers (cam deviations if any, and fuel-trims for each cylinder.) Good luck!

Thank you so much for taking the time to explain everything in such detail and I do apologize for the format of my initial post. I will try to get a Porsche code reader and get back to you with the error codes. Another thing that happened is I bought a Redex petrol system cleaner, but the car actually had a check engine light, really rough idle and power limited error. Update: Now the car seems to be running great. The error is gone the idle is smooth. I wonder if the addative actually worked. Puzzling why the car ran so bad after the first start l at the gas station, when I added the Redex.

Great to hear it's running well now. Possibly a sticky injector that the fuel system cleaner cleared up. There is still value in getting a Porsche code reader, and seeing what codes were stored, and perhaps looking at a few of the values I mentioned. To do almost any diagnostics yourself on a modern car you need a code reader capable of talking to the correct make/model/year car. Unfortunately - there are enough variances between the electronics used in different cars that there is no universal tool that can do it all. If you do go that path - please take the time to post here what you find in the ECU module as far as internal codes.. (ones the OBD -II tools can't read).

Would that be a good obd reader: Foxwell NT510 Elite All System ABS SRS OBD2 Diagnostic Scanner FOXWELL NT510 Elite OBD2 Scanner Diagnostic Tool Key Coding Bidirectional Control, Full Systems Scan, Full Reset Service Why is The FOXWELL NT510 Elite Diagnostic Scanner Tool So Powerful and Reliable? Work on a lot of cars, Compatible with global OBDI / OBDII / EOBD. (20PIN needs to purchase... www.foxwelldiag.com I've never owned one, so I'm kinda lost when it comes to buying the correct one.

I’m sorry for typing this from a different account—my phone is being serviced, and I’m using my brother’s phone. Here are the codes I’m getting on my car. I’d also like to add that the error occurs while I’m cruising at 1,800 RPM and press the gas to accelerate. Before the codes appear, I feel a vibration from the engine.

Since I don't read Russian, the codes really are of little diagnostic value to me. I'd suggest switching the software to English mode and repeating the read.

P0300 Then you have 301 and 304 - meaning misfires on those cylinders. - same diagnostics as 300 It appears besides cylinder 4 misfiring - cylinder 1 is also misfiring. Given these are both on the same harness section - I'd be inspecting the harness for damage. Perhaps rodents? My reference doesn't have P0354 or U0424. Perhaps seeing these on your diagnostics readout in English might help.

The misfires and rought idle can be also caused by Hight Pressure Fuel Pump . Happened to me on my 981 and it was very difficult to diagnose. So you might want to look into that too

The 987.2 2.9L is NOT direct injection, hence - no high pressure fuel pump to diagnose.

I did a bit of Google Lens translation: P0354 = Ignition module, cylinder 4 U0424 = Check the contents of the fault memory of the air conditioning operator control unit I think for the moment we can ignore the U code.. you mentioned you already replaced the cylinder-4 ignition module. Have you tried swapping some around? Move the one on Cylinder 4 over to the other side - put it on one of the 5-8 cylinders, then clear the codes, start the car and see if the code follows the coil, or stays on the same cylinder. My bet right now is - it will stay with the same cylinder #4 - which would mean the coil is not at fault. IF the fault did follow the coil (moved to the other bank on the cylinder you put the questionable coil into) - that would actually surprise me.. The reason I'm betting that is the error code P0354 - which I have to guess is a code caused by no current draw from the coil on that cylinder. That to me - points to wiring. The fact that another cylinder in that bank is also tossing errors just doubles down for me the need to follow that wiring back to where it goes into the main engine harness.

I see. Thank you so much for sharing your knowledge and for the swift reply. I decided to change all the coils for now, to be sure the mechanics did not swap the wrong coil cylinder and will I tell them to check the harness if it's possible. I drove the car yesterday and the error never occurred. Such a weird issue to deal with.