Hello All, Any advice on a re-occurring misfire when all of the following has been completed? Running out of options other than throwing more parts at it. 223K miles currently with misfire codes. No coolant loss, consumes 1 qt of oil between oil changes 219K miles August 2024 · 4 Spark plugs · 4 Ignition coils · 1 MAF sensor · 1 MAP sensor · 1 EGR valve · Also cleaned EGR cooler and intake manifold all passages · Replaced transmission fluid 192K miles Dec 2022 · New head gasket · chain tensioner · PCV valve · spark plugs associated seals and gaskets
1. When does it misfire and what can you feel, hear, etc? 2. Brand of plugs, coils and maf? 3. Have you done the block egr flow test?
Starts with no cost egr block flow test At about 10:15 in the video he starts talking about the egr valve letting "air" into the intake manifold. He means exhaust gasses. A blocked egr cooler won't cause death rattle or misfire codes. A sticking open egr valve can cause rough low speed engine operation. Both will cause an egr code. Neither will cause loss of coolant. 1. When does it misfire and what can you feel, hear, etc?
Sounds bad like a burnt valve or a head gasket leak between cylinders. A dealer long block is as close to a new engine as they sell. They would send the head out for rebuilding after pulling the engine and tearing it down. Did they give you a price? Normally they are around $8,000 and could be more if a new head or accessories were needed. I would find an independent hybrid shop and get their diagnosis. It is worth it to drive an hour or more. If it needs an engine I would consider a JDM used in Japan engine with a guarantee.
So an update to the saga. Got a JDM engine replacement that measured compression at 165psi. Swapped the engine out but used original egr, intake, map, maf, cam timing, crank timing, oil pressure, vvt, coils, clutch thing, fuel injectors, 02 sensor, water pump, thermostat, temp sensor. Old engine measure 140 psi compression. Fired it up and it still has the same misfire. Now I also have the temp light on, but I read the temperature rising from 70 to 90 degree F with OBD2 so why the light? Can a water pump fault set the temp light on? Since I still have the misfire I have tried swapping cam sensor and vvt since they were easy to access with the JDM engine leftovers but still no change in the misfire. I also tried shifting to neutral while idling to try and rule out any transmission influence, but still a misfire. It wasn't using coolant before the engine swap, and I haven't driven enough to know on the JDM engine, but it is behaving with the exact same symptoms as before the swap so don't think it is a headgasket. I'm thinking Air, Fuel, Spark, Timing is all that is needed to run an engine so breakdown as follows: Current OBD codes: P0304 cyl 4 misfire, P0302 cyl 2 misfire, P0171 System lean bank 1, P0300 random multiple misfire, P219A pretty much the same codes I was getting before the engine swap. Air Compression - check EGR valve, cooler, intake - check MAP - check MAF - check ?O2 sensor - haven't swapped ?throttle body - wouldn't expect a misfire from this Spark Coils - check Plugs - check Timing Cam sensor - check VVT - check ?crank sensor - haven't swapped Fuel ?Pressure - how to check? ?Injectors - can swap with JDM core, but haven't as they are a different color? Try fuel injectors next? Any other thoughts? It's a decent car otherwise and now I just don't want to get beat.
Most people use the JDM complete. Changed the timing components from your old engine to the JDM? Wow. Sounds like you transferred a bad part from your original engine. And or have a bad connection on the wiring harness. Not clear if your parts from the original engine that you swapped over were oem. Any non oem part needs to go.
All parts from the original engine swapped onto JDM are OEM. Wiring harness crossed my mind, but where to start? Coil packs?
IMHO; you should be testing things to narrow down the problem - rather than just swapping random parts, since you don't know if the replacement part is defective or not. Especially the electronic ones. Did the misfires move? Assuming the JDM engine worked in the first place, you may have move the problem over from your old engine or you got a bad JDM engine. When you replaced the head gasket; didn't you check the block and head for warp and the cyclinder walls for scoring? That would've told you if that oil burn is from the rings, valves, or valve seals.
