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Infiniti Q45 Maintenance and Repair



  • 1994 Q Never had a car with remote and all thatbeeping alarms, but its a good question for alarm experts.

    I can get in to my wire diagrams on my 1990 to see the logic in the wiring for a door lock broke.It could have energized the cutout starter relay. I've seen something labeled cutout once I believe on mine. Sometimes I remove the battery ground connection, it wipes out the memory in the computer. I guess kinda like the Restart button on computers.

    Does the hood release still work?
  • greenq45agreenq45a Posts: 3
    i have a 91 q45a and it lifts when started but drops faston cut off, should i change struts-rack&pinon,or strut, or accuators/ and if struts do anyone know where to struts, i am from orlando,fla.
  • not sure of the system on your. I dont have such a system but I''ll look to find an answer.
  • ok my nephew bought a 91 q45a at first i thought he was crazy but come to find out not so crazy the guy he bought it fromreally famboozled him .
    long story short its on the ground like a old lincoln the fluid container is empty for the active ride and the right rear tire has about a 20 degree tilt inward. i am hoping that by replacing the accumulators and refilling the fluid (if you know what it is please tell me) she will lift back up any advice would be greratly appreciated .
    you can e-mail me at thank you in advance for all your help.
  • Hi all: My '92Q has developed a loud buzz in the rear speakers. It does not vary in intensity with engine speed and the radio/CD/Tape still plays through them, but the buzz is loud and constant. it doesn't matter if I'm tuned into a radio station, or set the radio to no statio, the buzz persists. Fading from front to rear or changing from left to right balance also has no effect. I'd change out the rear speakers, but don't want to do that if the probolem might be in the head unit. Any thoughts?THANKS! I miss my tunes.
  • So does mine .

    Im going to replace the speakers someday. Mine will go away if I shut off the powwer and turn it back on.
  • waliswalis Posts: 35
    if you're still using the factory speakers, this is what happens when the amps go bad. It's likely the amps. If you look at the rear speakers, you'd see a black plastic housing. Inside this housing are the amps for each speaker. You'd need to replace the amps. You can change the speakers to aftermarket, but be prepared not to get the same sound quality/clarity unless you're willing to change the head unit to an aftermarket as well.
    All four speakers have individual amp built in. They go bad after time.
    Good luck!
  • Thanks. 'llI look at it when I get in their next time.
  • Thanks for the advice. I don't want to go aftermarket, so the amps will be replaced and we'll see what happens. I appreciate the responses.
  • njoyn1njoyn1 Posts: 11
  • joesrjoesr Posts: 17
    I would review the recommended maintenance items before I let the dealer perform the items. - I have a 2002 Q45 and do virtually all the routine maintenance. - I follow the recommended intervals for the fluids/filters, tire rotation, etc.,.and make judgement calls on items such as the serpentine belts (I believe there are three) hoses, wiper blades, etc.,.-

    My first Q45 (94 Q45t) is still in the family and has 213,000 miles. -
    I changed the serpentine belts and radiator hoses @ 100K and 200K, but inspected both along the way. - My 2002 Q has 136,000 and I have followed the same approach.

    It is my observation that the dealer follows the "one size fits all" approach and if replaces items that don't necessarily need replacing. - I also notice that many of the items are "check" vice actual maintenace/replacement.

    The only items I had performed at the dealer was the 100k platinum spark pluy replacement.
  • Sounds like you got a good maintenance record. My Q-45 is a 1990. Its similar to the 1994 then the rear wheel drive was dropped.

    Like the last post I regularly change the oil and oil filter every other change according to the Q-45 service manual. 30K maintenance consist of one extra item the coolant, then every two years or 30K. Also change the air filter at 30K.

    I want to get under mine and change the rear differential fluid transmission fluid this year it has 125K on it.The platinum plugs should be changed at 60Kin my manual.

    My 1990 is on a blog at my
  • I dont get forum notices when someone ask a question.I I thought I did, and missed a months or so worth of old Q-45 questions.

    Your problem sounds like air induction. The engine is revving could be a leak somewhere in the vacuum lines . One thing I noticed when I tear mine down is all the ventilation hoses and clamps. the design is not like a traditional PCV system. The PCV is on the left rocker at the back and maybe one on the right too.

    Another area to check is the two hoses going into the duct that's going from the air filter to the Intake manifold. Squeeze this duct too to see if engine starts to run wild. It could be old and have a crack or leak This is critical to the MAF like in the last post If the MAF is bad it will run in default mode. You can disconnect the electrical connector to this part, it is right at the air filter where the part of the duct is square, as it leaves the air filter.

    I know its late but I hope you got the problem fixed if not I hope this helps.
  • I also need to change a headlight ballast on my 02 Q45. I have not been able to find any information on how to do so. Did anyone ever respond and let you know how to replace?

    Warmest regards,

  • q45azq45az Posts: 4
    I just bought a Q45 and it seems that the car is shutting itself down when i try to start it. I put a new battery in the car because when i bought it the old one was dead. Drove home and tried to start it and it seems the car is in a security mode or something the relay for the security is missing. There is no power to the car itself but a clicking noise coming from somewhere on the passenger side of the motor. Im not sure what else i can say so any help would be great. Thank you.
  • I get the same noise too. It happened this morning and another time when the battery was low.

    I pulled the relays in the black box till it went off it was the one marked inhibit I never traced it back to see what it went to but it was not starting only just cranking . I guessed it was just low on battery charge and causing the buzz.

    Inhibit relay goes to a module under the dash I think it was security or alarm module.I got my service manual here and will look it up.
  • q45azq45az Posts: 4
    Thank you mine wouldn't even crank but i pulled the cables and put a charger on it last night getting ready to go crank it now see whats up. I will look into the inhibit relay.
  • q45azq45az Posts: 4
    No luck HELP!!!!! After i reconnected the battery i got in to crank it and it turned over for like 2 seconds and didnt fire then went dead... By dead i mean the battery is charged but the car acted like it had a dead battery then it turned all electrical in the car off again like a protect mode or something. Any ideas????
  • Would appreciate any feedback as to where I might find a detailed procedure for replacing left & right valve cover gaskets. Most is straight forward but the left side appears to require at least the removal of the EGR and perhaps the intake manifold. Thanks.
  • My blog 1990 Q-45 has some details of repair I haven't put this one up but will today.

    In my removal I broke it down into hoses cables and the bolts and a couple more hoses when you get the manifold separated from the engine.

    From memory, I get up on the engine and look behind the engine to the top of the block. You ll see a Y type hose going to the idle air valve and another metal tube that runs along the top of the block. Try and get some pliers on the hose clamp to the metal pipe side, remove this hose clamp only The other two sides do not need removed. Now your going to remove hose clamps on the valve cover. The largest ones in the middle of the cover next to the intake on the intake manifold. Theres two on the left valve cover and one on right valve cover. That is all the hoses for now

    I switch to throttle cables next, the three on the right side of the engine. The two upper ones that go into the firewall must be removed, leave the other one alone. That one goes to the other side of engine throttle plate, and stays on the manifold when you lift it off. The two nuts are 14mm size. Use two wrenches and turn the nut on the firewall side of cable while holding the nut on the end of the cable side. If it doesn't move, you have your adjustment for later. Then lift cable off from between the metal clamp by open the throttle by hand at the lever next to these nuts and slide the end of the cable out of the slot made for removal. Then re-tighten the two nuts back together. I re-tighten the nut you loosened to the one that never moved.This is your adjustment point when you reinstall it. I mark this nut on the top with red paint for a reference in case it moves a little.

    Next is the EGR valve. It can be hard to get to the tube that runs down to the exhaust manifold. I used a 90 degree nut wrench. like those plumbers wrenches but lighter and smaller. Open it up to 15/16 and put on with the wrench towards the front of the engine and try to break it loose. Dont have to remove it completely. It helps to have all the wires on the valve cover out of the way. Then get the other end of this tube at the EGR Valve, it is 1 1/4 size.

    Back to the hoses I missed the vacuum booster hose and its clamp on the top backside of engine and fuel regulator hoses.Its down under the manifold on the top of the block by the Y hose and the other fuel regulator diaphragm hose is next to the Idle Air Valve (IAC) on the back of the engine too but higher up on the left side as you sit in the car It pulls right off. One more hose clamp to be removed is on the front of the engine right side comes from the bottom of the manifold into the hoses you removed in the first paragraph. It is smaller, 3/8 size. and wont come off until you lift the manifold and twist the manifold as you remove it, then it comes off. This is the next to last hose holding the manifold on. The last hose is the coolant hoses. There is two, one on each side of the opening for the intake by the throttle valve. I hold the intake up in the air after you have removed the 16 10mm bolts holding it all down. I should have included it in the last step for bolts. Use a 2x4 wedge undr the manifold to keep it up while I remove these last two hose clamps. These are 3/8 size hoses with antifreeze in them. Now is a good time to start draining some of the coolant in the radiator before you start or these hoses will give you a small flood on top of the engine.

    Oh yea I remove the two bolts (12mm) on the EGR Valve and remove it, This gives me more access to the last hose I just mentioned. Also remove the diaphram above it,on the top of the manifold next to the EGR. Two 10mm bolts hold the diaphram on.The only hoses that I didnt mention run along the valve cover to some metal tubes and solenoids on the left side of engine, they also get removed. They bolt to the left valve cover. I pull off the small hoses at each end and the two more that connecte to the intake by the throttle valve. The whole assembly of these hoses cant be removed until you remove the manifold.Remember to put it inplace first before you install the intake manifold on reinstallation.
  • rearwheeldrive - thanks for taking the time and trouble to post the details of your disassembly. Before joining this forum I searched motor manuals and the internet for some details about this undertaking. Given all the comments I found on the internet about Q45 owners experiencing valve cover gasket leakage I was surprised to find nothing published. The '96 model might be different from the '90 model in some ways. There were two major unknowns (to me) to which I was trying to find answers before beginning the project. (1) Would it be necessary to break an A/C line to remove the right side cover? Specifically, the lines near the firewall that are close to the cover. (2) Would it be necessary to remove (or move) the intake manifold in order to remove the left side cover? There is an approx 3/4 inch metal tube that extends from beneath the intake manifold outward over the left side valve cover. Didn't look like the valve cover would clear the tube. Checked with a couple of Infinity service departments about the procedure. All said they bend the tube to clear the cover. Long story shorten....I didn't bend the tube because it would involve major surgery to replace if I broke it. I forged ahead and was able to remove the 16 bolts that hold the manifold on the block, disconnect one bracked from the manifold and was able to lift the manifold the necessary distance to clear the metal tube. As for the right side - it was tight but I was able to remove the cover without breaking the A/C line near the firewall.

    Should anyone read this post and want pictures and details for a 96 Infinity send me a request.

    Again, thanks for your help 'rearwheeldrive'.
  • Your right those two areas had me scratching my head. The A/C lines along the right side,and the EGR tube over the left valve cover.

    Never bend or break anything on this car, parts are too expensive. I think I tried to get the cover off with it loose but I never had to bend it. It makes installation easier to remove it completely once you get the valve cover off. The right side cover is tough getting around the A/C lines I used a 1/4 drive socket wrapped in masking tape to help my two fingers loosen the bolt because the ratchet gets in the way of the A/C lines The fuel lines I left on too.

    My pic's are detailed, but I have them in two different software programs and cant find then in the old software that pops up in the download window of this site. I'll find them today.
  • Sorry for no response I didnt get an email that usually notifies me of a new message.
    Sounds like the battery is dead. What is the voltage?. If you dont have a meter Radio Shack sells one for $4.00 dollars.

    I think your car has something draining it. To immediately fix this, disconnect the ground cable at the battery every time you park the car. Mine is 13mm size nut on the negative (ground) side of the battery.. Its the correct cable to disconnect when you want to take electric battery power off the whole car, not the positive or red cable, its the hot one Since the NEG. cable is wired to the car body at the other end of the cable, the battery won't short out or spark if your wrench accidentally touches the car metal too when loosening it.

    Its the positive cable that goes to all the switches and fuses that is hot, and is never touching the car body. If you accidentally touch the wrench to the car body when your removing it first instead, you would cause a direct short in the electric system bypassing all the switches and fuses and electric parts, and cause sparks too.
  • I finished the Q-45 intake removal on my blog. Check it out before you start yours.
  • I just wanted to warn everyone that is in the San Jose, CA area never to take their Infiniti for service at Frontier Infiniti on Stevens Creek. I brought my FX in for it's 30K maintenance. They told me it was done so I picked it up after work. I paid for the service and they said wait a couple minutes while they bring the car out to the front. However, they can't find my keys. They said this apparently happens often and they might have just left the keys in another car. They "tried" to look for the keys for about 20 or so minutes and said it might turn up tomorrow. They made it a big deal that they provided me a loaner car.

    The dealership said they were going to give me a call the next day. I get a call 11:30AM the next day informing me that my car was no longer in the lot. I was even asked if I had come back to the dealership that same night to pick up my car with my spare (So I'm the victim here and I get accused of taking my car). They "discovered" the car missing AM and it took them 4 hours to contact me. I immediately head over to the dealership to file a police report. They have no clue as to what happened. No internal investigation was done. No camera footage was available. Basically considered the whole matter as between me and my insurance. They were very passive and had poor customer service. I love Infiniti and if you car about your's, I highly suggest don't bring it in to Frontier Infiniti on Stevens Creek (San Jose, CA).
  • dyess5dyess5 Posts: 13
    The ballast replacement is not a major deal but it will take some time. I had to replace my headlight after a pole met up with it. It took about 3 hours. The ballast is mounted under the headlight. The ballast will come out with a little help, you will understand when you get to it. I downloaded a tech manual from, but it seems it is no longer there. I do remember that I had to remove the inner fender well and a few bolts were hidden. I will try post the manual tonight on , it is the manual for the 2002+ cars.

  • When I accelerate or step on it to pass, my 'Brake' and sometimes 'Airbag' light(s) come on. They go off whenm I let off the throttle.
    Can anyone help?
    Thank you kindly,
    James S.
  • I wrote the msg about the Q45 whose 'Brake" light would come on upon acceleration (and sometimes the 'Airbag' light, too). Last night coming down I-75 home, the Brake, Battery lights came on steady, and the Airbag light blinked on and off regularly. I have some familiarity with Japanese cars and this said "Alternator" to me. I hadn't thought of that, as the alternator in the car is NAPA's liftetime guaranteed model, three months old. But that's what it is, the alternator. Gotta swap it out again. Thanks for the help!
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