2000 Q45

[Bobby Mac]

I recently purchased a 2000 Q45 coming off a lease. Car has about 53,000 miles. I am disappointed so far with gas mileage. I am getting only about 16mpg in combined city and freeway driving. Only 20 in freeway. Is this normal?Car seems to have a little gas smell when started up and seems to smoke out exhaust more than my 97 I30. I took it to dealer for 52,500 minor. No negative feedback from dealer. Also hesitates a bit when shifting from 2nd to 3rd.

[PalmerWMD]

The 97 thru 01' generation of Q 45's has a repuation as being almost bulletproof.But previous owner maintenance is very important often lease cars dont get a whole lot of TLC.

Please describe your shifting prob more.At what speed?What rpm? what weather? only at some weathers? only when warmed up or only when cold?, when (if ever) was the transmission fluid replaced ?

Your milage should be a bit better but dont know enough about your drving habits aggressive driving and/or a lot of short trips can get milage even lower than you stated.Tell us more about the "smoke" as well.Q's have a large exhaust system , it can take 15 minutes or more to steam out the condensation in winter conditions sending white vapor out.Sometimes looks bad, but often doesnt mean anything.

Or... your smoke isn't blue right??have you checked the condition of your oil?(milky, yes/no)

I tend to get 15mpg in city and 20 mpg in easy hiway driving w/ first gen Q's (which use a bit more gas than 97-01).

Fred...

PS: Despite your early issues, congratulations on your new car!:thumbup

[Q45tech]

About time for a complete induction clean [normally done as an addition to the 60k plug service]........have a transmission flush done, not just a pan drain and refill.

How many years miles do you plan on keeping the car?You didn't say what emission comtainment area in NC....oxygenated fuels get 8-10% less mpg [even though the EPA says only 5%].....extra oxygen [in fuel] fools the O2 sensor/ecu into demanding more fuel at cruise! Plus the BTU value of fuel is 5% lower!

23-24 mpg on all FLAT freeway driving at 60-65 mph no AC......any excersion above 70 mph will get you down to 21.

A 4.1 liter always consumes 4.1/3.0= 1.36 more fuel correcting for lower cruise rpm say 25%.

[Bobby Mac]

I plan on keeping the car 5 years another 100K. Love it.

When accelerating slowly the problems is at 35-40mph at 2200 rpm. The transmission seems to hesitate, drop back a bit, then move forward into the shift. This is in cooler weather. If accelerating quickly, this occurs at 55-60mph. I described to a sales rep at Infiniti of Charlotte and they told me she had same problem with her 2002/3 Q45. There was a warranty fix where they installed a box. I was told that did not apply to the 2000. I can live with it. Smoke is white and does seem to dissipate after warming up about 15 minutes. It has also been cold and damp here and that has an impact. Just had oil changed at Inf of Charlotte with 52,500 service. The transmission fluid must be OK because I asked them to check it. As for gas mileage, I am guessing with my driving habits I am getting about what I should. Service mgr told me the only thing he has seen these cars do is wear out two belts after about 60K.He also said the plugs should be good until 105K. You agree?

We love the car. thanks again.

[maxnix]

The transmission fluid must be OK because I asked them to check it.

A fatal assumption such as this can lead to high repair bills or early transmission replacement. Probably all the dealer did was to ascertain there was fluid present and (maybe) the fill level was correct.

I suggest you read the prior posts on transmission flushes. It would be a shame not to maintain yours while it is still young.

[Q45tech]

A few enligthened dealers offer AT flushes , the old school mentality of making $3,000 in revenue on a transmission replacement weighs heavily on doing much to extend unit life.

It takes a lot of $129.95 flushes to equalize against $3k.......like 23 flushes.When the ATF color changes flush it!

[BadQ45t]

Your gas mileage seems way off. My 97 gets a solid 20 MPG with combine driving and I'm not a lightweight on the gas peddle.

As for you problem with the shifting, you still have a factory warranty, right? I'd go to the dealer and if they cannot feel it take them for a drive and make sure they notice it. My 97 shifts smooth as butter so you should not be having this issue.

I'd also complain about the gas mileage, but when you hit 60k you'll need to do a full service including the transmission flush (which I did) and that may improve things. But I'd demand to the dealer that the transmission problem be fixed.

[Steviek1]

Bobby Mac,

I just found this forum today and read your quote about the 2000 Q transmission hesitation. I have the exact same issues with it. I have had the regional DAM take it for a test drive with me. They have run the Nissan computer on it for a couple of hours of driving and no faults have shown up. I have had a Nissan Master Tech Instructor from my area discuss with me how these transmissions use a valve body that shifts differently than traditional vehicles, with sort of an "a" to "b" shifting function. It's as if there are two vacuums in the valve body that shift from one gear to the next, rather than one with most vehicles. This is supposed to "smooth out" the shifting according to my master tech friend. Having driven German cars most of my life (this is my first rice rocket) I find the Infiniti shifting mechanism to be extremely sloppy and not akin to what I was used to with Audis, VWs, and BMWs. I can live with it, too, but I think there may be a greater issue with the valve bodies on these cars that the dealer doesn't really want to address or can't seem to address? (To their credit, however, they did take it for several test drives and hooked me up with the District Area Manager (DAM) for get his opinion. They would have replaced the valve body if it needed it, but the computer tape showed all clear.) They did do a complete B&G backflush of the transmission system for me. This seemed to help for a while, but on cold start, especially damp mornings (and headed uphill) I notice that it LAGS between shift points from 2nd to 3rd gears. It's also noticeable if you really lay into the gas pedal and give it full throttle. It kind of jumps or jerks into gear - 2nd to 3rd. Not very smooth, but seems to be "within specs" as the dealers say.

I must say that my local dealer is very responsive (Jim Coleman Infiniti, Bethesda, MD) and they have been more than patient with my requests on a vehicle that is out of the warranty period. Heck, they just put BRAND NEW 17" WHEELS on my car yesterday for nothing due to a factory recall notice!! That's over $2000 worth of wheels for nothing!! I think I'm just going to have to live with the poor shifting until a "fault" comes up on the computer. I still need to get my master tech friend to drive my car in the morning on cold start and give it a test drive. The DAM didn't seem to be as sharp or knowledgable about the car as the master tech is. Good luck. I love the car, but wish it handled better on turns and over bumps. Can't seem to compare to the Germans' ride. But the Q is smooth as butter on the open highway. I also get about 15-16mph in city driving and about 20-22 on the highway, even at 75-80 mph steady. Drop me a note and let me know if you've resolved any issues. Fred, any comments?

Thanks,

Steve

I plan on keeping the car 5 years another 100K. Love it.

When accelerating slowly the problems is at 35-40mph at 2200 rpm. The transmission seems to hesitate, drop back a bit, then move forward into the shift. This is in cooler weather. If accelerating quickly, this occurs at 55-60mph. I described to a sales rep at Infiniti of Charlotte and they told me she had same problem with her 2002/3 Q45. There was a warranty fix where they installed a box. I was told that did not apply to the 2000. I can live with it. Smoke is white and does seem to dissipate after warming up about 15 minutes. It has also been cold and damp here and that has an impact. Just had oil changed at Inf of Charlotte with 52,500 service. The transmission fluid must be OK because I asked them to check it. As for gas mileage, I am guessing with my driving habits I am getting about what I should. Service mgr told me the only thing he has seen these cars do is wear out two belts after about 60K.He also said the plugs should be good until 105K. You agree?

We love the car. thanks again.

exact same issues

[Steviek1]

Fred, take a look at my last post and let me know if you have any comments? Thanks. Please forward to my e-mail: [email protected]

[Q45tech]

The transmission software was designed as if the engine was always putting out brand new Torque at such and such rpm.

Dirty plenum/ TB, 53k plugs, less than perfect injectors, fuel composition, worn transmission, etc can all add up to a 3-5-10% less REAL power at low to mid rpm.

The AT adjust the shift pressure based on AT temperature and TPS voltage [load] [throttle position].

Flushing AT and changing filter/cleaning pan is all you can do for AT..........

[PalmerWMD]

Stevie:

I think Dennis aka Q45tech summed it up very well.

Consider a <thourough> TB and even plenum cleaning I once spent almost half hour handcleaning the inside of my plenum(which was off) while dennis was cleaning IAC valve.

All the Other things he mentioned could do with some attentian as well, this may imrove some of those thinsg you mentioned.

BobbyMAc:The plugs are <not> good until 105k but only about 60k.Alsways must stick with NGK plugs (no Bosch of any kind).

Fred...

[Steviek1]

Thanks, guys. What is a plenum and what is the TB you refer to in the post?

Thanks,

Steve

[Steviek1]

What is the IAC valve, too? Thanks a lot. Will cleaning all of this make it run like new??

Steve

[PalmerWMD]

Plenum is the big spider on top of enigine and throttle body is the attachment right in front (butterfly).Both can benefit much from cleaning.

IAC= Idle Air control valve.

"Will cleaning all of this make it run like new??"

It might, if your plugs and injectors are good.

Fred...

[Steviek1]

Plenum is the big spider on top of enigine and throttle body is the attachment right in front (butterfly).Both can benefit much from cleaning.

IAC= Idle Air control valve.

"Will cleaning all of this make it run like new??"

It might, if your plugs and injectors are good.

Fred...

Fred,

Thanks for the reply. One other quick question. Is it possible to "clean out" a stale-smelling air conditioning system without simply having it inhale heavy duty chemicals that mask the odor?? I have had this done once (previous owner was a smoker) and it was great for a whole season. Now, after the winter is over, the AC is foul smelling again. Any physical fixes that I can do to this Q45?

Thanks again for your forum. I appreciate it a lot.

Steve

[PalmerWMD]

Yes tehre is a physical fix.You open up the dash to get to the wehre the rottign leaves are collecting and hand clean them out.

A better guy than me will answer on how to get there.

Fred..

[911/Q45]

Sometimes you can clear the odor by mixing about a half cup of bleach with a quart of water and spray it through the system with the A/C running. That kills the mold that grew there during the winter.

[Steviek1]

Thanks, guys for the anti-stink fixes!! Anybody wanna tell me how to open up the air intake area so I can clean out the old, moldy leaves?? The dealer also told me that he thought blockage in the air intake can also cause loss of power and the sluggish shifting problem. Anyone else have this same problem?

Thanks. I really appreciate this forum. I used to own an Audi, and was totally dependent on the Audi Q list. This is even more organized.

Steve

[Steviek1]

I'd still like to know what the "TB" is that you are referring to in the above post? Can you show me a picture of a "plenum" and an "IAC"?

Thanks again,

Steve

[Q45tech]

Short of disassembling the HVAC and removing the evaporator for cleaning [a 6-7 hour job]........the heater core would add another 6 hours [requiring total removal of the entire dash].............you are stuck with chemical cleaners/spray masking agents.

Leaving the AC on high and fresh air can suck some moisture ladden air in at a spray car wash [use the high pressure wand and spray into the cowl intake vents].

Mold is common build up when you turn car off with AC still on!Try turning AC to economy to dry the evaporator 1-2 minutes before shutting car off...........this will get rid of moisture.

[BadQ45t]

If you have a warranty I'd press the dealership. My 97' gets rock solid 20MPG combine driving and longer trips I get 23-24 if I keep the speed under 80. I'd press for fixes, I have none of these issues. One of the things I like the most about the car is how smooth the transmission is, like silk.

If you don't have an extended warranty I'd buy one, even though I've just passed through 3 years with the car and haven't needed it once, for around 1,200 bucks it was a good piece of mind.

[mhartler]

Hi guys... I have this car and love it. I have an issue that's occurring...my car is intermittently over heating. One time it happened standing in traffic on a 85+ degree day with full a/c on. I turned on the heat and opened the windows and the car cooled. When I opened the hood, if you're facing the car, left side of the engine compartment had radiator fluid "spattered" all around. I took it to the dealer and they said I needed a radiator flush. They also said the radiator was only 1/2 full when they opened it. They also checked the cooling system and said all was well. Well...about a week later, same conditions, it happened again. Called the dealer and they kept the car 2 days and found nothing wrong. No problems for weeks until this past weekend. Driving about 75 mph on a flat highway on a 75 degree day, the temp needle started creeping. It just got shy of the H when I turned off the a/c and put on the heater to cool the motor. When I go to my destination, I smelled radiator fluid. Has anyone had any similar problems or guesses as to what's wrong? I'd like to go to the dealer with maybe some kind of suggestions. I even took a picture of the temp gauge with my cell phone camera to show the dealer that I'm not nuts.

Thanks.Marc

[Q45tech]

Overheating at 75 mph on a 75F day is SERIOUS!

Either there is a coolant leak [pressure test will comfirm] or an air flow blockage or rad coolant flow blockage or a bad thermostat.

[mhartler]

I would hope the would have pressure tested and check the thermostat. The thermostat is still my thought that it's the culprit. These are such tell tale signs. My 70 Olds 442 had the exact same symptoms and it was the thermostat. I'm taking it in again tomorrow for them to check it.

[duck3986]

I purchased my '98 Q with 62k miles and had the exact same observations and questions about the transmission and smoke.

Turns out, unless it's blue, what your seeing is moisture and my car always does it in cooler and damper weather, more than any car I've had. It hasn't burned a drop of oil in 30k miles so no worries there.

I had the exact same transmission lag, especially when acceleration slow-moderately up a hill. If I lay into it and let the rpms get over 3k, it would shift much smoother.

I did new plugs, new airfilter and transmission flush which all helped. Then after 5k miles I drained the transmission pan and added an equal amount of Mobil1. After doing this twice, the lag isn't gone completely, but shifting is better, especially when cold.

My mileage averages 18-20mpg, combined city and highway. If I do over 70 or 75 mph, mileage does drop. Also, laying into the gas in the city, acellerating quickly will drop mileage quite a bit. It's a heavy car!

Don

[maxnix]

Drain and refill is no substitute for a true mechanical fluid replacement, pan drop, clean and filter replacement. Look in member's rides under my user name for a picture of a B&M 70264 transmission cooler installation on a FY33.