Altima shakes during idle and while driving. Service engine light comes on and then goes away?

This is one of my pet peeves! Over and over

people are advised to have AutoZone or the like read the codes and tell them what's wrong. Or that you should purchase an inexpensive reader and do it yourself.

Fact: A code that says misfire cyl. 2 does not

always mean that you need to replace the spark plug, wires, cap, coil or whatever they try to sell you. A lot of the employees at those places don't have a clue as to all that is involved to properly diagnose the indicated

problem. I hate to say it but a lot of working mechanics will also simply replace the part that

is listed in the code's description. One common example is a code saying that a particular O2 sensor is reading rich or lean.

Far too often the part gets replaced without any further testing, when in fact, there are a

few (at least) other problems that could cause that code to come up; primarily anything affecting the correct fuel/air mixture reaching the cylinders.

Before I forget: a steadily lit MIL or CEL is

usually an emissions related problem and safe to drive. A flashing lamp means Shut Down!

there is a very real risk of causing further damage by driving with a flashing CEL, as it

indicates a mechanical failure (such as a cylinder not firing) that can get worse rapidly.

In your case there are things that need to be eliminated as causes before replacing any parts. Cylinder compression on suspect

cylinder AS compared to the others, don't check just the one. A reasonably accurate

spark tester should be used to ensure not that there is spark, but that there is spark at the required level. In other words you can check

under no load and with a small gap and think that your spark is good, when in fact you lose the spark under more demanding circumstances. The ignition wires need to be checked for any obvious flaw and then tested with an ohm meter (DVM). Although here too

the wire may check out fine while not being used, but start climbing a hill or accelerate hard and it then creates the problem.

There could be a small leak in the headgasket

between two adjacent cylinders. There could be a broken piston ring causing low compression. There could be a leak in the intake gasket at the suspect cylinder, affecting

the mixture in that one cylinder.

I'm sure that you're getting my point. For every problem showing in the DTC there is a

specific routine, or troubleshooting flowchart

that should be followed; when it is, the odds

of replacing only the faulty part are very high.

If you feel that you have the tools and savvy

to undertake diagnosing the problem yourself

may I suggest thinking about a subscription

at ALLDATAdiy.com For about what you'd pay for a pretty much worthless manual at

an auto parts store you can get a one year

subscription for your vehicle that will allow you

access to Technical Service Bulletins, Recall information that isn't always made public,

wiring diagrams, flowcharts, specifications, etc., etc. (No I do not work for them in any way)

As you can see, there really is no way to give

you anything more than an educated guess

as to what's causing your problem. Granted,

the first suspect is often the problem, but it gets expensive quickly if it isn't in this one case.

Good luck to you,

quietman

This is so odd, or I guess it isn't, but I've had the same exact problem! I also have a 2003 Nissan Altima with a similar mileage to it and it's been shaking for some time now. After repeatedly hearing from our usual mechanic that the car is fine, we decided to take it to Nissan and spent about $800 on God knows what the fix the issue. Literally a day after I felt the car begin to shake again and it would continue on and off. Finally, it got to the point where the service engine soon sign was not only constantly on but would begin to blink as the car did the same things as you've mentioned in your description: trouble accelerating as though there wasn't enough power, and mostly shaking when I was idle or as I began braking. I went back to my regular mechanic since Nissan told me I had to wait a day or so to (maybe) get my car checked, and according to his device it said there was a misfire that involved replacing one of the coils, as you've mentioned. When he looked at it the day before however, he thought it was the spark plug that needed to be replaced, as you've also mentioned. We ended up replacing one of the coils ($80) and so far I've felt a difference, the light hasn't showed up again yet, and it seems to be a lot better. He told me to inform him if anything changes. I'll let you know as well. Best of luck. (Even though this happened to you 4 years ago) lol What ended up being the prognosis anyway?

Yup this car has a lot of recalls....i don't think its an injector...And that makes sense that the car would be shaking if a cylinder wasnt firing...go somewhere else because coil packs are pricy but its not a 400 job..600 for injectors crazyz=.and they shouldnt be charging you 80 bucks just to check it...find a diffrent shop they want to rip you off....if the car has overheated i read the headgaskets go bad and coolant gets into the clyinder... causing misfire. checkout this site..with more problems just like yours .....http://www.carcomplaints.com/Nissan/Altima/2002/en...

Car Jumping Service

Try cleaning the new plug so that the electrode metal is showing on both L and center electrode. If there is a factory black oxide coating, remove it.

You may have a water leak, that generates steam.So fix any water leaks.

If you have a distributor, check for water under the distributor cap.

If you have distributorless engine, check for water at spark plugs or inside spark plug boots (remove them and clean and dry them). When the engine cools the warm air inside the boots cools and sucks water in.

If still not fixed, replace the spark plugs because the insulator may be cracked from water hitting it while hot.

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You may have more than one problem. Also check for un-connected vacuum hoses.

YOUR FIRST MISTAKE IS TO LISTEN TO AUTOZONE EMPLOYEES. THEY ARE PART SALEMANS WHO JOB IS TO SELL PARTS. THEY DON"T KNOW HOW TO DIAGNOS CAR PROBLEM. THANK GOD YOU DID NOT ASK THE PRIEST FOR CAR ADVICES. HAVE A WELL TRAIN TECHNICIAN CHECK OUT YOUR CAR SO YOU DON"T HAVE TO SPEND MONEY ON PARTS YOU DON"T NEED. BASE ON YOUR PROBLEM, THE MOST COMMON PROBLEM ON ALTIMA IS A BAD INJECTOR. ALL,ALL ALL, 1996 AND NEWER VEHICLES CHECK ENGINE LIGHT WILL FLASHES WHEN THE COMPUTER SENSE THERE IS A BAD ENGINE MISS FIRE.ONCE THE ENGINE MISS FIRE SLOW DOWN ,THE CHECK ENGINE LIGHT WILL STAY ON UNTIL YOU FIX THE PROBLEM. YOU NEED A SCAN TOOL TO CLEAR THE CODE ONCE THE PROBLEM IS SOLVE

The "power" problem sounds like a throttle body. I don't think that has anything to do with the shaking.

I had the same problem, and it was the ignition coils. Went to Nissan dealer and they put it on there computer to find the problem.

motor mount solved mine. They tend to start failing right around 100,000 miles.

go to a nissan dealership and tell them the problems your having and they will put it on a computer for u