Most of you know about the writeup I did a while back on Q45.org to give a brief (heh) overview, and Ive re-read this and I have made some changes. THIS IS THE ONE YOU WANT TO READ.

Congratulations! You are looking at one of the finest cars ever created. However, they are not without plenty of shortcomings. Here are some major stats and facts about the 1st generation Q45. A lot of my own personal opinion and experience is interjected, so if you don’t agree, sorry you didn’t take the time to write this article!

* They came stock with the VH45DE, and all aluminum powerplant, 4.5 liters, rated at 278hp/296ft/lbs of torque. This is also one of the first cars to use VVT (variable valve timing), it controls the amount of intake valve overlap thus optimizing power. That said, when they rated the VH45DE in 1989, in Japan, they rated the engine WITHOUT VVT. In Japan, if an engine is rated over 280 horsepower, there is a stiff tax, so to avoid the tax they rated it without VVT installed (which consequently isn’t on the 96 model year, because of emissions regulations). Thus, the engine produces closer to 310hp and 330ft/lbs of torque. * These cars use one of the best paint processes in history. You will be very hardpressed to find a Q with bad paint, unless it was completely abused. They are also very resistant to rust. * IT was the first car to be offered with a FULL ACTIVE SUSPENSION. Basically it is a computer controlled system, and a network of VERY COMPLEX hydraulic actuators, accumulators, and there is literally no roll inside .5g and they have that built in so drivers do not overdrive their tires. New active computers can be purchased from Japan to make the active ride even better.

* It came with dual exhaust, 3 way catalyst system with ultra high flow cats. Any exhaust modifications past removing and replacing the rear resonator is a measure in futility. There is no power to be found in the exhaust system, and new catalysts are not recommended as they will not flow better than stock or last as long.

Variations of the Q45:

Q45

Q45a: Designation for the Q45 with active suspension

Q45t: Touring model, minor differences except for upgraded wheels, and a rear sway bar.

Difference between the 90-93, 94-96; and problems associated with them

90-93

The first generation Q45 is said to be the best of a PERFORMANCE-LUXURY sedan, where performance is first and luxury is second. The 90-93 is said to be the purest of these. Real leather door panels, vinyl covered dash, some of the best plastics in the industry, and not a hint of bling-bling wood trim or anything like that. Everything was built for a purpose: No grille because it creates wind resistance, no wood trim because its worthless, and so on. There are many features that are only in the best of cars today. I dare you to find EVERY interior feature in 20 mins in the first time you sit in a G50 Q. The car also came stock to start in 2nd gear, to have really smooth starts, and then when you drop it to 1st, it unlocks the fury of the VH45. They used plastic where they shouldn’t have, and that’s the timing guides. Unfortunately it’s a well researched and known ordeal, but not always known by many old Q owners.

A description of the timing chain guide issue

Defect: On the slack side of the timing chain system, they used plastic backed timing chain guides. What happens is they eventually crack, break, and this causes the chain to flop around, and it can and eventually will jump a few teeth. The VH is an interference engine, and most of the time it completely destroys the engine. However, this is only prevalent in mostly higher mileage engines. Most failure are around the 120k range, and some have gone higher. A friend of mine and fellow Q owner, Jesda, has a 92 Q45, that has 185,000 miles on his Q. Just recently, he had his guides replaced. Here is some pictures of his ordeal: http://q45.spilky.com/iowa/ . He and the previous owners were VERY OCD about changing the oil (mobil 1 synthetic), and that is what I feel that saved his engine. As you can see on the pictures, he was on borrowed time. ALL 90-93 Q OWNERS, IF YOU THINK “THIS WONT HAPPEN TO ME” YOU ARE WRONG BECAUSE EVERY Q OF THIS ERA WILL FAIL AT SOME POINT IN TIME. It is very unfortunate to see these engines go to waste, because they have only broken in by the time most have failed.

Fix: Metal backed guides were introduced. You switch the old guides out. If the guide pieces are missing, you MUST drop the oil pan and remove the old guide bits, because it will clog the oil pickup and possibly starve the engine for oil. On an interesting note, by the time you’ve done 2 timing belt changes on a early Lexus LS400 you have already paid for the guide job on the Q, and you only have to do it once!



Other common issues: Please see our TECH HELP section for more information

* Injectors- For some reason the injectors are weak on this car. 4 of them can be replaced with the plenum on (the silver “spider” atop the engine). If the engine starts to shake at idle and you get a check engine light, most likely it is an injector. * MAF connector- Corrosion occurs on the connectors of the MAF, and causes a false reading, and ultimately a vibrating idle and driveability issues. An easy way to test this is to wiggle the connector at idle, and it the idle changes then you must clean it. *Transmission cooler- This is very prevalent on the 90-93. The stock cooler is more of a “heater”. An external cooler is recommended to prolong life, as the main killer of a transmission is heat and not wear. The recommended cooler is a B&M part number 70268, and can be had at http://www.summitracing.com for about $60. See http://www.q45.org/trannycooler.html for installation instruction. * Knock sensors- The case of the knock sensors eventually crack and fail (usually around 120k) and this causes the computer to retard the timing 5* or so, causing decreased acceleration. If this is the case, you get to remove the plenum.



94-96

Everything is applicable except for the following changes:

* The timing guide issue is not applicable, they came with the updated guides * A softer suspension for a better ride (but in my opinion still very stellar handling) * Softer seats, traction control and other interior accents were added. * Exterior styling, with a grille and some other minor things. * Power headrests and tilt down mirrors in reverse * 1st gear starts were now standard, and a lowered 1st and 2nd gear to maintain smoothness

Basically all off the same issues EXCEPT the guides are there, except not really as bad. Injectors were restyled and are more reliable, but they still fail, especially in areas with iffy gas, California and Arizona being the worse. In most peoples opinion, these are overall the best Q45s to get because of the better reliability and lower cost to own, and more luxury. However its not by any stretch of the imagination gone drastic changes, its still very much a drivers car.

The 96 model year got OBDII (on-board diagnostics) and lost variable valve timing as a shortcut to meeting emissions standards, thus much closer to advertised horsepower and torque (actual power output is higher than advertised).

What to look for when buying a 90-96 Q45.Exterior

First thing is to visually inspect the exterior. Look for variations in the paint (there should be little orange peel, if any). If there is, its probably been repainted at some point. There are twp common rust areas on the Q, and that is on the rear, where the plastic bumper meets the rear quarter panel. Its uncommon to see a Q with exterior rust, and if there is run away, because it probably hasn’t been maintained well. However its just that small spot I wouldn’t worry too much. There is also a common area, on the door sill of the rear doors. If you open the door, it would be where the bottom of the door meets the body, and up in that flat area. There is a small seam there, and I have noticed rust there on a few different Q45s.

Interior

Just make sure everything works. Don’t worry about any STOP LAMP INOPERATIVE messages or something similar to that because they can all be fixed easily. Be concerned if it does say TRANSMISSION MALFUNCTION, but it does not necessarily mean something is deathly wrong!



Something Ive noticed on many Q is the little interior lights go out. I have many out in my Q right now. They go behind many switches and there are tons of them. Another thing like that is the rear ash trays, most flop around and are broken.

Engine

There are many things with the Q engine that can be easily inspected. A look inside the oil filler cap is worth 1000 words. You need to really look down in there with a flashlight as far down as you can see, and you should only see cleanness. If its black or really dark brown stay away.



Check the engine oil. The level should be good, and the oil a nice golden color if its been recently changed. When you wipe it off, in the little round part of the stick, there should be no goo there. Oil color can be decieving, so be sure to look in the oil fill area.



Other fluids: Brake fluid (should be clear; slightly yellow); transmission fluid (red, and should NOT be brown or smell burnt); powersteering fluid (same as tranny fluid).



With the engine running at idle, you should feel no vibrations, it should run about 650rpm fully warmed (just below the line between 500 and 1000). If its below this then the intake will need cleaning, and do NOT ADJUST THE IDLE SPEED, it needs to be corrected by cleanliness. You shouldn’t really hear much, you will here some slight ticking of the injectors opening. Its very soft and anything else should be taken note of. The fan should show resistance when moved (engine off).

On the lift

Check for body damage, rust, and other damage. Also check the suspension components, namely the rubber bushings for leaking of silicone or cracking. They are used with age and not with miles. Check the rear subframe area for stains, the bushings could be bad.

"* It came with dual exhaust, 3 way catalyst system with ultra high flow cats. Any exhaust modifications past removing and replacing the rear resonator is a measure in futility. There is no power to be found in the exhaust system, and new catalysts are not recommended as they will not flow better than stock or last as long."

True but theres one thing to be had, V8 SOUND!!!! These cars stock sound like they have some kind of muted 6 in them. I assume its "supposed" to be that way. But that part might discourage a person from unlocking the potentially beautiful sound from their car.

BTW killer write up, i took the old one with me to the dealer when i got mine

CrimsonQ wrote:True but theres one thing to be had, V8 SOUND!!!! These cars stock sound like they have some kind of muted 6 in them. I assume its "supposed" to be that way. But that part might discourage a person from unlocking the potentially beautiful sound from their car.

Not mine! I like the serious moan emitted as the revolutions race to redline. This is no Fraud nor Cheby cast iron block, pushrod actuated , two valve head V8. Neither should it sound like one. Need to listen to other hightech V8 like MB, BMW, even Northstar. Maserati is even better, but the Ferrari has a 180° flat crank, so it will sound different. Ever hear an Infiniti Pro series V8? That's a destroked Infiniti V8!

I prefer the B&M 70264 higher capacity ATF cooler.

Whether the JDM replacement active suspension computers actually imiprove the function of the active struts and valves is undocumented. Without faster acting computers and sensors, ride improvement is not achievable. It is still world class. Most of what the sensors do is change ride height.

I think this guide needs to stress the importance of the inspection of the fluids more since bad ATF can lead to tranmission replacement, bad PS fluid will lead to steering rack replacement, and bad brake fluid will lead to ABS pump replacement. All are expensive.

Also, I always recommend obtaining the Infiniti dealer performed service history before viewing the car so one knows exactly at what one is looking.

Finally, having a senior Infiniti technican (one who was trained on the G50 in 1989) inspect the car can save a lot of heart ache.

Minor things: HICAS was discontinued in the 1995 t model, 1994 and after had remotes and automatic dimming rear view mirror and tilting in reverse side mirrors, remote entry fobs, and R134a refrigerant. t and a models have the smaller front anti-sway bar, the standard has no rear anti-sway bar, the t model has the small one, and the a model has the large one.

This guide needs to be linked from the NICO home page.

I have a 1994 Infiniti Q45 that needs new brakes, a new power steering rack and new struts... Way too much money for me. Is there anyone out there who needs this car for parts? I am in upstate New York.

I have owned 3 previous Q45s. A 91, 92, and 94.

I am telling you don't get into this ownership blindly. It will make you hate an otherwise great car.

If you want to REALLY enjoy the car, you need to do your best to restore it to the condition it was originally sold in.

I'm talking about completely redoing the suspension. Don't ignore all the rubber and misc parts. Do everything.

Do all the under plenum hoses. All the belts. Everything.

The most important part of the equation if you're not a DIYer is to really attempt to find an Infiniti master mechanic with experience servicing G50s.

If you can commit $5,000 to bringing it back to life, you will have a seriously nice vehicle, with everything old replaced with new again.

One only needs to look at Q45techs maintenance habits, and why he has never had any breakdowns.

Proactive versus reactive maintenance

Hey Wes, awesome write-up!!!

Thanks alot, ton of good info here!

Wes: Since your the Q45 man, can you keep an eye out for a 94 Q45? I decided I want to pick one up... I'll dump the J30 I have if you can find one.

I only want a black one though - no other color is acceptable! If you find one, let me know ASAP, as I'll drive whereever I have to to grab it.

Did the 90-04 style Q45 have any type of traction control system...?

THANKS!

1993TanJ30 wrote:Did the 90-04 style Q45 have any type of traction control system...?

TCS was available on the first gen (90-96) Q45's.Except the early Q45a's.It was standard on T's and in later years standard on all models

TCS was not standard on "t" models (at least for 94~96). Greg's 95 car does not have it and I have seen one other 94 "t" model that did not have TCS. I have it on my "t" model however and I hate it now that I live down here in Miami. When I lived in NJ there is no way I could have done without TCS.

TCS was standard with the touring package (it was a sub package called like the winter driving package which came with the BBS wheels, seat heaters, and so forth..) You could of course request not to have it...

Good info, thanks! Has anyone actually driven one of these cars through the entire winter?

Almost 300HP, RWd - I can't imagine even with TCS it'd be possible when you get into 6+ inches of snow...

Any info?

elwesso wrote:TCS was standard with the touring package (it was a sub package called like the winter driving package which came with the BBS wheels, seat heaters, and so forth..) You could of course request not to have it...

My 1995 does not have it and there is no deletion on the OEM equipment list.

what are my options on engine swaps? could i install a g35 engine into my '90 Q45? i want to make it into a manual car. is this all possible?

qdude21 wrote:what are my options on engine swaps? could i install a g35 engine into my '90 Q45? i want to make it into a manual car. is this all possible?

G35 engine would be by far a down grade.. you *can* do whatever you want but wether or not its feasible...

putting a manual in will not be easy but it can be done.

so do u guys kno any FAQs/walkthroughs to install a manutal transmission on the '90 Q45? what transmission are u suppose to use?

qdude21 wrote:so do u guys kno any FAQs/walkthroughs to install a manutal transmission on the '90 Q45? what transmission are u suppose to use?

No one has done it... It will cost about 5 grand to do it right, and then you have to find someone to do it...

NOTE that no MTs will bolt onto the Q45 engine (vh45de)

What does the transmission malfunction light mean. My car runs fine and fluid level is ok.Is this a false reading of the actuators ect.

2. Do you have to pull the fuel tank to remove the fuel pump on 1990 Q45?

Do know if there would be any issues associated with using dual transmission coolers?

cmccort wrote:Do know if there would be any issues associated with using dual transmission coolers?

I dont know why you would do that...

I don't get it, it says "considering an older Q (90-01), but there isn't any mention at all about the 97-01...

I agree. The title should be renamed:

"Considering an older Q (90-97), READ THIS FIRST!"

007

Falkdesigns wrote:I don't get it, it says "considering an older Q (90-01), but there isn't any mention at all about the 97-01...

I think thats a good thing that means things that dont normally go wrong with them...

Things ive noticed that go wrong with them seem to be very far and few between, the only thing is that the suspension is kinda tough and expensive to rehab... unless you are JDM tyte

awesome info elwesso dude. I had a 1990 crimson Q which replaced a BMW 535i. It was so reliable and drove so well I picked up the 94 Q45t and still drive it today. Its absolutely the best car I have ever owned. My daughter is learning to drive it now. It sure beats a civic or sentra, and she is thrilled. I plan to keep it for another 6-8 years if it will have me. Oh yes, it has 106,000 miles and gets washed all the time. I'm thinking of replacing the exhaust system if I can find a good muffler for it.

Aloha from Hilo, Hawaii

Magnum PI

I own a 90 Q45 for the last 15 years, used mobil 1 since 2nd oil change, I was not aware of this guide problem nbut am now Thanks to your information, I have 172000 miles on her and I guess I need to consider doing this, sounds expensive to do, any idea what the cost of the parts are and the time it would take to do it?Thanks for your timeStewart

Its all right here just a paragraph down from top.

http://www.q45.org/techhelp.html

Great write up! My experience and opinion exactly. I finally have the date set for next week. It is guide time for me. I have a cherry 91 with only 51K on it! Finally changed off the original Michelins last summer. Have used synthetics through out since discovering this sweet car three years ago with only 26K on it. Trans cooler as instructed and now the guides. Why do all the Nissan and Infiniti dealers claim to have never heard of this defect?! They have agreed to take my money and change them anyway, how benevolent. Only mode is to install 93 trans controller for 1st gear start. Just came back from 2 weeks in Germany with a Turbo A6. Really nice, but the Q is more stable at 180Km.

Problems to date, window controller on the driver side, typical sound system malfunctioning speakers, tape player... Sun roof clutch slippage, and more recently leakage from around the master cylinder when the car sits for long periods.Love my Q and have really benifited from all of you sharing the info, thx!

hi, i am considering buying a 98 q45.are you saying that the only problem with this generation is the suspension?si there anything else that goes wrong with this car?

i test drove this car when it was wet out, stepped on it and the wheels spun quite a bit.how well does the TCS work on these cars?thanks for the help

It doesnt really seem that the Y33 had trends of things failing unlike the G50...

Falkdesigns wrote:I don't get it, it says "considering an older Q (90-01), but there isn't any mention at all about the 97-01...

If you can send either Wes or myself some info to add, we'll gladly do so.

For now, I think there are very few things to look for that would have "gone bad" on a Y33, beyond excessive owner abuse, which should be obvious to a potential buyer.

Wes and I came up with something last week, I'm sure he'll put up soon.

Destuck and locked, please see the new threads and then the new and upcoming rehabbed sticky.