I have a 02 6 speed maxima with 145,000 and looking to tune it up. I am going to clean the k&n air filter, change oil, new plugs, and drain and fill transmission fluid. What else should i be doing? Also, noticing when i am in second or third gear around 2k rpms and accelerate pretty hard it hesitates for a second then takes off. Another thing is the gears are feeling rough when i have to shift espcially 1st and 2nd gear. What is the cause of these issues. Thanks for you time.

 

When you say rough what exactly are you experiencing? Shifts between gears are rough/grinding or the engine or bogging down?

At 145k i would consider (if they haven't been replaced and if money is not a problem)

o2 sensors
coils
cats
fuel filter

 

The hesitation is a feature, typical of long tube CAI's. Install a short intake and it's gone.

 

-Spark plugs
-PCV Valve
-Air filter (cleaning)
-Inspect all vacuum hoses (replace any which are cracked
-Tranny fluid replacement
-Clean MAF sensor (search for the detailed procedure, it might help with your hesitation issue)
-Replace fuel filter
-Drain, flush, and replace coolant
-Drain (or suck up) as much power steering fluid as possible from reservior and replace with ATF fluid (do this a couple times over the course of a month, maybe once per week, and you will basically have new fluid in there)
-Inspect all brakes and replace pads, rotors as necessary

On the spark plugs I would only go with the NGK type...whatever is your fancy, platinum, copper, or iridium.

 

Sometimes it is really hard to put it in first gear or second gear when i am down shifting.

 

Why are you down-shifting into first? You're killing your tranny!

 

I would use Redline gear oil and change the fuel filter as well.

 

Precats are probably clogged. Get new ones or get headers.
Oh, and you could try some seafoam if you would like. Just for good measure...

 

if it's hard to get in second or first, but forcing it in works (you might hear a grind). Then it's probably synchros.

 

Never seen anyone recommend replacing the cats as part of a tuneup.
I'd wait on those until I got a SES light. Same thing with the O2 sensors.

Which Redline gear oil does the 6MT take?

 

Replacing synchros, how much would it be and should i replace all of them? I should be using Redline?

 

Guesstimate, $2800. Yeah, if I was going to disassemble a transmission, I'd change then all.

Amsoil, Redline, and others all make decent tranny oil.

 

Damn, don't have the money right now but if i were just to drain and fill the tanny fluid with Redline would that be ok. Also, if i didn't get the synchros fixed what is the worse that would happen?

 

What Redline tranny fluid should I be using?

 

When your synchros are gone, you'll have to slam it into gear every time. You can help them out by "double-clutching;" that is, shift into neutral, then the gear you want. Large trucks are like this, by design, but their transmissions have at least two counter-shafts, sometimes three or four, are insanely heavy, and built to last more than 800K miles before the transmission itself needs servicing.

So to downshift into second from third:
1. Clutch pedal to the floor
2. Move shift lever back one notch into neutral
3. Release clutch pedal
4. Clutch pedal to the floor again
5. Rev-match and shift into second, releasing the clutch slowly as normal.


If my synchros were on their way out, I'd start saving for a 6th-gen 6-speed. But, if you've never seen inside a transmission before, I'd recommend hanging on to the one you have, just for learning purposes. They are nifty little inventions.

I would also delete/replace the pre-cats (headers are cheaper than replacing them!) before they damage anything. I know the pre-cats are shot on my Maxima (~125K mi), and I'd suspect the cat is fairly clogged, as well. There's no reason to wait until it destroys something to replace it. Save up, switch them out, and greatly enhance your odds for no calamities happening.

 

It almost sounds like it could be time for a new clutch kit. I would say you have a greater chance of the clutch being worn out then your 6speed to have internal issues. How many miles on the current clutch?

 

Why on earth would he change his intake? I would think this is a last resort after all other portions of a normal tune-up and inspection are complete and no issues found.

 

Just reporting my observations on MY car, and has been reported by others. If you've got a similar intake, feel free to chime in.

 

O2's yes, but precats can clog a lot over time, leeching power and NOT throwing any codes. When I did my header install, I used a grinder to cut my precats open, and the were CLOGGED!! There's no way those weren't robbing power. I agree that it's not absolutely necessary to replace precats, but on a high mileage car, the old ones will almost definitely be the main and most likely cause of decreased performance.

Some things can rob power without throwing a SES code. (clogged precats, MAF going partially bad, and knock sensor just to name a few...... moral of the story: you don't always have to wait for an SES light to replace things)

I've probably had 4 or 5 respectable org members recommend replacing precats on my car (high mileage) as a way to maintain performance and original drivability.

 

the clutch is original, it has 145,000 on it so it might be time to replace it.

 

Well it may be part of his issue...but he needs to do the simple stuff first.

It is like saying "overhaul your transmission" when the clutch hasn't even been changed. Funny thing...other members are actually suggesting this.

 

Well, the OP is the one that has said his syncros need replacement....on the other hand, he's also being counselled to replace his cats, "just because".
That's a pretty expensive "just because"!

 

Yup...at this point buy a new Maxima.

 

Country24 => as part of maintenance, you could also clean your MAF with MAF cleaner spray (found at any advance auto parts).

 

at 145k the only tune up i really did was change trans fluid. Right now at 151k, the 02 light came on, and occasional cam sensor...

 

do u no if theres a chip available for the max, i have a 4th gen

 

Hahahahahaha

 

Use Redline MT90, it costs about $12 bucks.