1990 Infiniti M30 Coupe 3.0L V6 from North America
One of the greatest Nissans never known
- Nissan-BOSE stereo head unit's internal amplifiers fried and the unit was replaced with one out of a 1992 Nissan Sentra E sedan.
- Driver and front passenger seats have started to tear. This isn't severe but is obvious and you can clearly see how the tearing gradually worsens over time.
- Transmission shifts from first to second unbelievably hard but only when it hasn't warmed up fully. When it is warm, the transmission shifts so smooth you seriously don't feel it whatsoever, as I know it used to back when it was brand new. Now, however, it decides to drop out of overdrive a random while traveling high speeds around 70-80 MPH. Either it won't lock into overdrive to begin with or it sort of "falls" out of overdrive and the RPM just soars.
- Both valve cover gaskets have started to leak and spew oil onto the surrounding engine components. This isn't too bad of a problem, as the oil doesn't burn and create an odor, but the cost to repair both valve cover gaskets at this time for a vehicle of this age and rarity would just be too much. The car's performance is barely affected by the leaking gaskets, if at all, and oil leakage is not enough to require constant refilling.
- The alternator died at around 135,000 miles (that's just a random guess, I don't really remember). It was immediately replaced by an aftermarket refurbished alternator and it now runs perfectly fine with no electrical problems at all.
- The windshield washer fluid tank has mysteriously sprung a leak and now liquid will not stay in it at all. Pouring washer fluid in will just cause it to come straight out and onto the ground. This doesn't pose too much of a problem, though, since the car is almost never driven in the winter and anybody who drives the car doesn't really use washer fluid to begin with.
- At some point, a bit before the alternator went out, the power steering pump kept making an extremely loud whining noise when the wheels were turned far enough or on full lock. This was determined to be caused by the power steering belt and was soon fixed. The noise no longer persists and the steering works normally.
- The power door locks don't quite function as they should. Unlocking the driver's door from the outside with the key will only unlock that door, and the same goes for unlocking it from the inside. The passenger door, however, will unlock both doors from the inside and outside. Normally, the driver's door is supposed to lock and lock both doors, but as of now it only locks both (and unlocks itself). This probably due to some problem in the wiring or electrical system that I've yet to find and repair.
- As common in M30s with automatic climate control, the display has gone out and works sporadically every few months. This isn't too big of a problem for me since I don't use the climate control that often. As long as I remember what the temperature was last set to when the display went on, I'm fine.
- The driver's door sags a bit, creating an unpleasant smashing noise when closing it. The sag is not noticeable to the eye unless you're actually on your knees and examining the point where the door and the mechanism on the door jamb meet. The passenger door, however, closes smoothly and does not sag at all.
- Also common with M30s is the fact that the trunk switch broke. It was actually broken when I first acquired the car, and I replaced it with the cruise control switch out of, once again, a 1992 Nissan Sentra E sedan. It worked fine at first but until recently the switch has stopped completing the circuit and the trunk has to be opened with the key. I'm currently looking for another switch to replace this one.
First off, I love this car.
Many people criticize the Infiniti M30 as being an old, ugly, cheap "rear-wheel drive Nissan Maxima", but it truly is not any of those things. Sure, the styling is a bit 80s but this car is in no way cheap by means of build quality. This is, after all, a Nissan. It's got a Nissan heart and Nissan build quality, and those things still shine through today.
The M30 is a remarkably solid car in every way possible. The engine, although it never had that much horsepower to begin with, pulls strong regardless of other mechanical problems and the transmission is still able to shift smoother than seriously any other car I have EVER been in. It goes about its business without a single fuss or care in the world - it does what it is supposed to do, and it does it well.
The interior is comfortable despite its being a two-door coupe, although the same cannot be said for the small back seat. Front legroom is spectacular. I have relatives that are 6 feet tall and can stretch their legs out all the way without touching the end of the footwell.
The leather seats are comfortable even though now they've started to wear and tear. When the seat is moved back you are sitting with your legs practically stretched out in front of you, presenting a very, very comfortable seating position whether you're driving or sitting in the passenger seat.
The climate control is practically lightning fast when it comes to air conditioning. Since this car uses R12 refrigerant instead of today's R134a standard, it is much, MUCH faster at cooling air than cars today. In Auto mode, the climate control works as fast as it can to get the cabin to and maintain the specific temperature you set it to.
Much like "modern" systems of today, it will moderate blower speed and refrigerant amount constantly using temperature sensors located throughout the cabin to maintain that temperature whether you're trying to cool or heat up the car.
Nissan's Sonar Suspension II adjustable suspension system does an excellent job of controlling ride comfort and shock stiffness. On the Comfort setting, the ride is literally butter-smooth. I can honestly say that for bumps even of considerable size, the only evidence you'll have of hitting them is the sound the tires will make.
On Sport, the shocks stiffen quite noticeably, creating a much more agile and obviously sportier driving experience. I do admit, however, that the shocks don't exactly stiffen enough for a 3333 lb. car to become a sports car, as it still leans a little too much in corners. Nevertheless, the Sport setting barely sacrifices butter-smooth ride comfort for much improved handling.
The brakes on the M30 are a miracle from god. Anti-lock brakes came standard on all Infiniti M30s and my god do they work well. They can stop this 3333 lb. chunk of metal from 80 MPH in the blink of an eye, as well as ALMOST any other car today can. The ABS pumps fast enough to keep you from skidding during slippery braking conditions but is also quiet.
When taking an off-ramp at high speed with the steering wheel cranked to the side and the brakes working hard, the ABS is neither felt nor heard at all. For a technical person like me who does understand how anti-lock brakes work, the ABS in this car, paired with the seat belts, driver's airbag, padded dash, and reinforced steel doors, works wonders to give you that safe and sound feeling.
Speaking of sound feelings, the interior of this car is one quiet sanctuary. At 70 MPH there's no wind noise at all and the cabin stays quiet enough for you to have a normal conversation with other passengers. At city speeds, taking off from a red light presents no road noise at all; it's just your breathing and the engine's strong, raspy exhaust note. I've been in this car while it was doing 95 on the highway and it sounded just as quiet as it would at 70. The same could be said for that feeling of safety.
In my eyes, the Infiniti M30 is truly a remarkable car. It is no doubt the rarest Infiniti ever made, with a rumored 12,000 in total ever produced between its years of 1990 and 1992.
This was a car the public never saw, whose older brother, the Infiniti Q45, took all the limelight away from. Even now, people refuse to look past the 80s styling and the beat up exterior and see that this is indeed an excellent car.
Even though this car was sold during Nissan's worst possible financial time, Nissan did not skimp out on its legendary build quality and reliability. This car is truly one of the best Nissan has ever made, whether people realize it or not.
To me, this is one of the greatest Nissans never known.
Would you buy another car from this manufacturer? Yes
Review Date: 21st June, 2008
20th Mar 2012, 02:19
An 07 or 08 Nissan Altima trunk switch / dash switch is a perfect replacement for the M30's switch. I replaced my 91 M30 convertible's with this, and now I have a power trunk release that works. Just an FYI. PT # Nissan's is 25380-30Y00. I was looking for a replacement, and a fellow Ebayer gave me this info. Plugs right in. Not the same appearance, but not many would know. It works.
Also, if you have an M30 Convertible 91/92 and need trunk support lifts, Tuff Supports # 612081 is what you need.
12th Jun 2016, 01:29
My 1990 M30 is also popping out of overdrive at 65-75 mph. Is there a simple fix to this - i.e. A new overdrive button/switch. Or, is this a transmission tuneup or complete rebuild? I've only got 105K mileage on my M30 and plan to keep it for quite a while.
Just looking for advice on how to proceed.