# 2002 altima idle problems



## CoopDaVillain (Feb 18, 2015)

2002 altima 2.5l 5 speed...215k miles...a little back info...I've had a multiple misfire code on, along with a blinking check engine light for about 6 months now. I personally changed the plugs coils and fuel injectors...still same problem. Its only at idle with the a/c on...car seems like it wants to die, I drop it in neutral and give it a little gas to keep it running. About 6-8 months ago when all this started, I was getting a code for the cat...and had a major loss in power...due to finances at the time I couldn't afford a new cat\manifold so I went with the aftermarket header...and straight piped all the way back for half of the price of a cat...I call it my angry lawnmower haha...could that also be affecting my idle issue? Not enough back pressure? I burn a ton of oil...about 2 quarts every week driving close to 100 miles a day...Now for the main question...is it worth it to break down the motor and do piston rings, replace valves if burnt, and all new gaskets?? Or just buy another motor? I'm gonna do all the work myself...just debating if it would be smarter to drop a grand on a eBay motor instead of buying new internals and getting the head resurfaced...and just save my old motor for spare parts...any opinions will be greatly appreciated. People tell me to get rid of the car, but its sentimental to me...and I absolutely love it. 215k and it drives so smooth there's not a thing wrong with it besides the idle issue


----------



## CoopDaVillain (Feb 18, 2015)

Also changed out cam and crank sensor


----------



## smj999smj (Jan 1, 2006)

You likely suffer from poor compression as well. The early L31's with the QR25DE fell under a campaign due to so many with oil burning issues. I doubt it's still active, but you may want to have Nissan check for open recalls and campaigns. Apparently the ECM program ran the engine in suck a way that it caused the catalyst substrate in the upstream converter/exhaust manifold to break apart. The ECM controls the variable valve timing to crack open the exhaust valves during the intake stroke to accomplish EGR, rather than use a conventional EGR valve. So, what happens is the bits of broken substrate get sucked past the exhaust valve and into the combustion chamber, scoring the cylinder walls, creating low compression and oil burning. The campaign included updated ECM programming, added heat shields, and, when necessary, a new engine short block and exhaust manifold.
Whether you rebuild your engine or go with a remanufactured or used engine is really your decision based on what you can afford and your abilities. Price out your options and take into the consideration of how much time you want to spend on your project. If you don't have time to wait on machine shop work or rebuilding, then a reman or used might make better sense. Of course, with used, there is always the gamble of getting a bad engine. Warranty is something to take into consideration, as well. When you are done, it would be a good idea to have a Nissan dealer install the most recent ECM software if not already installed. Since you are burning oil, it would be a good idea to replace the oxygen sensors. Also, if you have a rear converter, the oil that ruined your old front converter is now damaging the rear converter. As far as your idle, it's pointless addressing the concern if you have a bad engine. The oil it's burning and it's contamination of the spark plugs could be causing your misfire. It's kind of like worrying about a tire vibration when you know the tire is bald; address the main issue first and then see if the problem still exists.


----------



## CoopDaVillain (Feb 18, 2015)

Thanks for the reply...yea i might stay away from the ebay used motors, i think im just gonna rebuild it in my spare time, very good point....i dont want a used motor with the same problems. Car just died on me this morning, wont start....i guess its time to pull the motor and see whats up...


----------

