Misfire in Altima 2.5
- Thread starter Tom NJ
- Start date
My Corolla had a check engine light and horrible misfire last spring. It ended up being the... I'm going to forget now...a valve thingy in the emissions system that gathers fumes and opens and closes to burn those fuel tank fumes off. In other words, I never would've guessed that simple part being the issue. It was stuck open so created a vacuum leak. Toyota tech found it in 30 minutes before closing and it was ready at 9am the next day. Sometimes a decent tech makes life cheaper than throwing parts all over at it.
Having a family member with a 17 Rogue with same engine, since its posting my curiosity piqued with this one. Waiting/hoping for an update here.
Okay, so I bought a thin walled 14mm plug socket and pulled the #2 plug. Visually I don't see anything unusual. I then swapped plugs between the #2 and #3 cylinders, cleared the codes, and started the engine. Still had a misfire, and still read it in the #2 cylinder.
My code reader reads "Misfire in #2 cylinder detected" when set to "Pending Codes", but the reader also has a setting for "Permanent Codes". Under this setting it reads "Random/Multiple cylinder misfire detected". What is the difference between Pending Codes and Permanent Codes?
Also I noticed some mouse debris in the engine area. Considering how the wires are bundled it seems unlikely that a mouse could chew just a wire to the #2 cylinder.
My code reader reads "Misfire in #2 cylinder detected" when set to "Pending Codes", but the reader also has a setting for "Permanent Codes". Under this setting it reads "Random/Multiple cylinder misfire detected". What is the difference between Pending Codes and Permanent Codes?
Also I noticed some mouse debris in the engine area. Considering how the wires are bundled it seems unlikely that a mouse could chew just a wire to the #2 cylinder.
Pending code is when a fault has been detected on an engine start/run cycle. Permanent code requires detection of the event on multiple start/run cycles.
Since the coil swap and now the spark plug swap didn’t affect anything, the investigation should now move to the fuel delivery, compression and timing.
Given the "DD" for this particular Nissan engine code, it's direct injected. The injector is going to be buried under the intake manifold.
Since you mention finding "mouse debris" in engine area, worth it imo to check the air intake system, the air filter and filter box. Should be relatively easy and quick thing to do.
Did not realize the 19 Alitma 2.5L was DI. That would make it different than the 17 2.5L Rogue I see.
Did not realize the 19 Alitma 2.5L was DI. That would make it different than the 17 2.5L Rogue I see.
Yes it is a direct injection engine, but only has 44,500 miles on it, so intake valve deposits should not be an issue yet. I peeked inside the air filter box and it looked good, but I will disassemble it tomorrow to examine more critically, and also clean the MAF sensor. If that doesn't work I'll have it towed to the shop.
I did my share of engine repair some 50 years ago (back when you could sleep two under the hood!), including valve and ring jobs. But in a modern car, taking off the intake manifold to find the injectors is more than I want to do. Besides, since the problem seems to have occurred overnight while garaged, mouse damage is now top of my list. I'll let a real mechanic sort it out.
I did my share of engine repair some 50 years ago (back when you could sleep two under the hood!), including valve and ring jobs. But in a modern car, taking off the intake manifold to find the injectors is more than I want to do. Besides, since the problem seems to have occurred overnight while garaged, mouse damage is now top of my list. I'll let a real mechanic sort it out.
I'd drop it at a trusted mechanic, or dealer. Like I said, my Corolla had a sudden, inexplicable plethora of misfire and such codes and it was emissions related. Had nothing to do with anything aside from some silly, $90 valve thingy that's removed with a couple bolts right on the top back of the engine bay. Stuck open caused a vacuum issue and all the codes for misfires and fuel issues and such. It could well be a wire or something somewhere but I've often found if you don't have a checklist in a mechanics book, you'll often end up wasting your time. Quick check for anything obvious (seems like you did most of that) and send it off to someone who troubleshoots this stuff daily. Unless you want to spend your entire day with a multimeter. But that's up to you. Sometimes the $150 diagnosis and couple hours of labor (if simple fix) is worth it...
Check vacuum lines
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Do you have a code reader that will read long term fuel trims? If your injector is fudge that should tell you. If the trims are good +\- 5% then I would bet on a carboned valve. Or if not a mouse bite.
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Purge vsv on the evap caused a misfire? Thats a first for me, usually all i see with those are the cel causing most folks to address that come time for inspections since no driveability concerns.
But i do agree, if you have access to a good mechanic, time and money well spent letting them handle it. Finding a good mechanic part is the hard part.
Evap purge valve I believe it was! Yeah, tech at Toyota said it failed and stuck open creating a vacuum leak leading to messed up fuel trims and multiple misfires. My code reader showed all the codes and on my 45 drive from work to the dealer I captured all the fuel trim, O2, etc. data and emailed the service advisor the logs. Tech confirmed his readings showed same as mine. He said he checked all the hoses for vacuum leaks by pinching all the emissions and vacuum lines and when he hit that one all the trims and everything went back to normal range.
Most direct injection systems have pipes and seals that are one time use only. So, if you were to remove an injector to inspect it or send it out you would have to replace seals and pipes and anything else that you loosened. This is the kind of stuff that can cause a major fire hazard if you reuse it because of the high pressure involved. So it's not the kind of thing where you pull it apart to get a look at it and then put it back together without changing any parts.
Were you able to verify an actual spark?
Nissan's GDI 4cyl and V6s aren't reported to be big carbon build up engines. I've got a VQ35DD with just over 100K miles on it and no problems.
My concern with a chewed wire on the injector or ignition harness is, this won't be covered under warranty and you'll have to deal with dealer "quality" and pricing. Your dealer might be great though. Who knows.
Nissan default fueling strategy does strange things on their GDI engines should you have a MAF sensor or air flow oddity. I went through this with my 2019 Pathfinder with an ill fitting aftermarket air filter. This did throw MAF and random misfire codes to the point the engine would not run.
Where I'm going with this is, check your air cleaner housing and filter element for chewing and mice.
Nissan's GDI 4cyl and V6s aren't reported to be big carbon build up engines. I've got a VQ35DD with just over 100K miles on it and no problems.
My concern with a chewed wire on the injector or ignition harness is, this won't be covered under warranty and you'll have to deal with dealer "quality" and pricing. Your dealer might be great though. Who knows.
Nissan default fueling strategy does strange things on their GDI engines should you have a MAF sensor or air flow oddity. I went through this with my 2019 Pathfinder with an ill fitting aftermarket air filter. This did throw MAF and random misfire codes to the point the engine would not run.
Where I'm going with this is, check your air cleaner housing and filter element for chewing and mice.
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If it does end up being a rodent chewed harness, your car insurance will normally cover it if you have comprehensive coverage.
My code reader is a cheap basic unit that simply reads misfire in cylinder #2. I cleaned the MAF sensor and inspected the air filter box and the misfire persists. I also put mouse traps under the car and along the garage walls. I'll have it towed to the dealer on Tuesday and will report back their diagnosis when complete.
Thanks all for you helpful advice, and Happy New Year to all!!!
Thanks all for you helpful advice, and Happy New Year to all!!!
