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Infiniti Q45 Maintenance and Repair



  • Yes, it could be a stuck caliper. I had this happen on my '95 Q45a. The caliper on the right front wheel occasionally froze and the heat created caused the vibration. Next time it happens get out and feel the hub of the wheel. If its hot, that's your problem. BTW, stop the car before you get out to feel the wheel! :D
  • I recently bought a 99 q45t with 162K miles(alot of miles) but I feel comfortable in my purchase because the car has had only 2 previous owners. The vehicle was used a company car for 5 years with all maintenance and required tuning (driven about 25,000 miles per year). The second owner has the car for about 20,000 miles before it was repossessed. For about 5 monthes the has sat on a lot undriven and unmoved. I am currently experiencing no problems but would like to know what type of maintenance you would recommend for a car with this type of mileage (recently had fluids and air filter changed). I also wanted to find out the typical problems owners experience for 99 q45t. I have tried to research as much as possible,but have not found any information.

  • 162k is a lot of miles for the year, but its not a lot of miles for the car itself!!!!! If all your fluids are changed (including brake fluid and diff fluid) are changed and fresh, then just do the plugs and that should be OK... maybe a fuel filter too...

    Theres a lot of reading available on the other website's ive posted before.
  • waliswalis Posts: 35
    Finally! I solved the vibrating issue with my Q. It turned out to be the drive shaft's center bearing (the center of the propeller underneath the car). The dealer priced the shaft at $1000 sice it can't be dismantled into pieces. They only sell it as a whole. I decided to try a local salvage company and got a nice one for about $200. It was installed three days ago and BINGO the vibration is gone. Thanks everyone for your input and suggestions. I hope someone can benefit from my crazy ordeal.
  • waliswalis Posts: 35
    Hello elwesso: how does one know if the spark plugs coils are bad? I removed one but I can't tell if it's bad or not. Please help!
  • Ahh yes the center bearing, i had thought that what it could possibly be... should have mentioned something about it, i could have hooked you up with a brand new one for about teh same price... with the updated design....

    hard to diagnose vibrations over the internet.
  • You can do a resistance test on them. if you have a service manual, just get out your volt-ohm meter and test it... however on most Q the coils dont fail often. On 90-96 ive heard of 1 confirmed case where one coil went bad, and on 97-01 just a few, not nearly as common as dealers what you to think.

    what symptoms are you experiencing. i know you have a 92 and im guessing you took it to a "mechanic" because it doesnt idle smooth. Coilpacks are the "generic" answer for those who dont know diddly about the car. Your probably looking at injector issues.

    Give this article to your mechanic or whoever is working on the car.
  • Good afternoon! A good friend of ours sold us a 95 q45 here a while back that need some work done. Very minor work in my book but I ran into a problem pretty quickly. The car needs brakes badly but I'm unable to get the wheels off. The car has been sitting for years so I thought maybe the wheels were rusted on. After some wd40 and a lot of tugging and pulling, they still won't come off. Is there some special tool I need to get them off? The lugnuts were rusted on pretty good also but I managed to get them off with no problem. I was amazed that this car even ran and it runs like a champ, even after sitting for as long as it did. It hadn't run in litterally 2 or 3 years. I jumped it and it fired right off and ran incredibly smooth. So all I need for it is brakes and we have a car that only cost us 50.00. The guy we bought it from was going to give it to us to get it out of his driveway but my wife didn't feel good about just taking it so he said 50 bucks. Sold! Anyway if I could get these wheels off, we'd have a very nice running car. Thanks for any help you can give me in this I REALLY appreciate it.

  • Wow ive never heard of that happening. Does not bring comforting feelings to heart!!! Pretty obvious to think that the car has been seriously neglected, then again if its been sitting outside for 2-3 years anything is possible...

    The only thing I could think of is to get a puller of some sort and put it around the spokes of the wheel... I assume you have the regular 95 Q "20 spoke" wheels, right??? Not the ones called "piepans" which look, exactly like an inverted pie pan... I might also try giving a mighy wack with a hammer to the back of the wheel.. You dont want to keep pounding on it but sometimes just that sudden blow will take care of it.

    Otherwise, you could try unbolting the caliper/bracket from the hub (shoudl be able to do it from behind, tricky but it should be able to be accomplished) and just push the whole thing off the studs... However, i think youll find the rotor will be even harder to get off. There are threaded holes on the rotor that you can insert a bolt into to tpush the rotors off.... :)
  • waliswalis Posts: 35
    thank you so much elwesso! I'd do the injector resistance test. Is there any diagram/instruction on how to change injectors on Qs and how difficult is it?? Thanks a lot!
  • Check out

    Theres more information regarding in the tech help section.
  • waliswalis Posts: 35
    thanks again! Is there any information on changing injectors? Something with diagram/pictures of some sort.

    That is the only link I have handy.. You can search the forum, theres tons of info on there. It will mainly depend on what injectors youre replacing...

    Actually, come to think of it, Im doing a full intake/injector/hose job on a Q next week, ill make sure you get some pics.... :)
  • waliswalis Posts: 35
    Thanks! I'd be waiting for the pics. You're very helpful!
  • These are not the spoke wheels, I'm sure he put custom rims on it at some point. I'm going to try again to get the wheels off this weekend at some point. Actually I wasn't sure if there was some sort of key or special tool to get the wheels off so it sounds like they are just rusted on and need to be "coaxed" off.
    Yes it was neglected for quite some time but my wife has fallen in love with this car. We even put it on a trailer and towed it from Oregon to Georgia where we relocated. So now it's just a matter of getting it registered, brakes on it and she'll have a great car to drive.
    There is a bit of cosmetic stuff to fix on the inside, (the glove box door just comes off) but other than that it's in awesome shape inside and outside. So for 50.00, she got quite a good deal.
    Thanks for the information you provided and I'll keep you posted on my progress. Also I'll see if I can find some pictures to post so you can see our 50.00 q45.

    Cheers, Tony
  • patpat Posts: 10,421
    That would be great if you would post some pics - you can upload them to your CarSpace page and then display them here.

    I'm looking forward to seeing this $50.00 Q45. :)
  • waliswalis Posts: 35
    Hello all...does anyone know what the problem might be on my misfire on take offs and it's very slow taking off. However, when on the highway, it moves well. I've replaced all 8 plugs with some NGKs. I also cleaned the airflow meter as suggested in one of the posts here but to no avail. I've dumped injector cleaners in the gas tank twice within the last month. I only use premium gas. WHat else should I do? PLEASE HELP!
  • Does the Q idle smooth or does it idle rough??? Remember Q take off in 2nd gear...!!!
  • waliswalis Posts: 35
    it doesn't have a rough idle but you can feel it's missing when idling thus making it shake slightly. The idle stays around 800. It feels like there's a bad spark plug but all have been changed. I noticed that I'm not getting good mileage on gas anymore. HELP!
  • waliswalis Posts: 35 there a place on Qs to check fuel pressure?
  • elwessoelwesso Posts: 42
    Youll want to go to an autoparts store, pick up a fuel pressure gauge and a T fitting. Simply take off the hose going from the fuel filter, install the T fitting and another length of hose back to the fuel rail and then install a length of hose with a gauge on the end... :)
  • maymanjmaymanj Posts: 10
    I havea 97 Q45. 107000 Mi. PS started grinding left & right. I added about 10 OZ over a 6 month period. It gets quiet each time I add fluid. I am worried that the pump is going bad. Don't know where the fluid is going. Help. What should I do?
  • waliswalis Posts: 35
    Hi, my Q is still missing pretty badly. It's gotten worse now. It hardly moves these days. The only time it moves somewhat is when on the highway with lots of struggle to accelerate. WHat can it be? I recently just changed the fuel pump,fuel pump control module, fuel filter, air filter, new NGK spark plugs. It burns lots of gas. It misfires when I step hard on the gas pedal trying to force it to move out of frustration. I love this car but I'm frustrated now. PLEASE, PLEASE, PLEASE...HELP...HELP...HELP!!!!
  • maymanjmaymanj Posts: 10
    I have a 97 Q45 and it had the same problem,eg missfire. The dealer couldn't fixit either. So I suggested to the shop manager that they buy a neon bulb spark detector-on a long handle.When they held it near each "Coil-On -Plug" the internal breakdown sparkover lit the bulb. 7 of my 8 were bad. Yes,they wanted about $800 to replace,but I convinced them it was a Quality Control problem (material breakdown with age),and they replacewd all 8 Coil on plug assemblies free. See, the engineers at infinity factory are so proud of their QC that they were honored to learn about this defect.Engine runs great.Jerry
  • waliswalis Posts: 35
    Wow...7 bad coil packs. Please give a little more detail on how to run this test on the coil packs. Is it something I can buy and run the test on my own? Please advice! Thanks!
  • maymanjmaymanj Posts: 10
    How do I get answer to this Question?
  • elwessoelwesso Posts: 42
    Im going to try and reply to all of these...

    mayman- You obviously have a hose thats leaking, it could be the high pressure hose.. Thats expensive to replcae, however you can take the hose off, take it to a hydraulics shop (think heavy machinery, IE farm equipment/trucks) and they can take the fittings off and put them on a new hose... If its a low pressure hose, thats cheap to replace....

    The pumps dont go bad except when you starve them of fluid!

    Im impressed you got the dealer to replace all 8 coils. Its got to be nice with that sort of stuff when NO ONE has the CORRECT idea of whats actually wrong! When you have no clue, of course you can blame it on quality control or something like that.

    Walis- You're not looking at a spark plug coil issue. The later Qs had problems with them to some degree, however they always get stupid owners to replace all 8 and make a killing when its probably only a couple thats bad. replacing all 8 will surely cure the problem! You most likely have a bad injector, did you perform the injector test I outlined?

    Unfortuately due to the policy on this forum, I am unable to recommend you to a better source of information.
  • patpat Posts: 10,421
    Why not just provide the information here? Your help with Q45 questions is greatly appreciated.
  • maymanjmaymanj Posts: 10
    Thanks ELWESSO, #53- I will look at that Hose. I know the shop that can Make it. Can you E-mail me the Isometric drawing Of pumnp & hose so I can see how to remove it?
  • caljoncaljon Posts: 1
    My 2003 Q45 makes a loud droning noise caused by some kind of vibration between 1,800 and 2,100 rpm, and has the same sound in any of the five gears, so it is not road speed related. My dealer has replaced the Y-pipe and catalytic converters, as well as adjusting and tightening the exhaust heat shields numerous times. I drove two 2002 Q45’s that my friends own, and they do not have this droning noise. In my most recent service visit, the dealer again verified the vibration in my car as well as in a pre-owned 2005 Q45. The noise is vibration related rather than noise coming out the exhaust pipe.

    In 2005 I recorded the sound while driving at 2,000 rpm in top gear on a smooth asphalt road. It is 20 dBA higher than at 2400 rpm. I can also feel a vibration on the floor of the car as it goes through the rpm range where the noise is the loudest. The vibration gets louder if the car has an increased load, such as climbing a hill.

    My service manager told me he has done everything that they are aware of to cure the vibration and noise. There are no technical service bulletins on this problem, although it seems to affect the 2003-2005 Q45 models. We previously owned three earlier Q45’s, and were completely happy with them, as well as my wife’s present 2001 I30. My Infiniti service department has been outstanding in every way, but they obviously cannot re-engineer the car.
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