3 Questions about QX4

[sowlerthjh]

Hi,

I have just bought a 2002 QX4 with 137,000km on the clock. Three quick questions:

1. I have never owned one of these before. It drives perfectly, although I don't have full service details. Are there any particular things to check or change before I use it daily?

2. The passenger window doesn't operate from the driver's door, only on the actual passenger door switch. Is this a known problem?

3. Should all 2002 models have active cruise control (where the car automatically brakes if a car is in the way)?

4. The last owner mentioned to me something about turning off the air conditioning/climate control before turning off the engine to avoid damage? Anyone know anything about that?

Answers will be very appreciated

SOWLERTHJH

[QX4ME]

1. This SUV is super reliable. I skipped 60K major service just to save some money. Only a few fluids were changed by an independent shop at a much lower cost, at about 75K miles. Although not a good practice, it proves its quality.
2. Is it front passenger side only or rear two windows too? Could it be the 'disable' button in the 'down' position?
3. I am not sure about that, but a few times I left A/C on when I turned engine off. I don't remember owner's manual says to turn A/C off first then engine off. Maybe next time when engine is turned on, it has more than necessary load on? When I noticed that I turned A/C off to let engine warm up easily.

I don't drive a lot so only 85K miles now. Bought it new and absolutely nothing has gone wrong.

[patqx4]

First off, congratulations! I bought my 2002 almost a year ago and its the best vehicle I've ever owned.

The first thing you should really do is the power valve screws threadlocker-on-power-valve-screws-pics-t304263.html
Check all your fluids and replace any you're not sure of. change the fuel filter and check the air filter. all the obvious stuff.
The biggest problems with mine are suspension related, but that's because I live in Canada where the roads eat through suspension parts faster than a fat kid eats through a bag of doritos.
There's also a recall for the front strut tower, get that checked out if you haven't yet.

If you aren't someone who likes messing with small electric parts, the easiest thing would be to replace that drivers switch pack.

Active cruise was an option for 2002, mine doesn't have it.

I leave the HVAC unit on when I shut the car all the time and haven't had a problem, but what QX4ME said seems like a reasonable explanation.

Good luck!
-Pat

[QX4ME]

Thanks patqx4 for bringing the recall up. Now I remember I saw the suspension recalled and checked months ago my car is not included since I am in CA. I completely forgot it.
Yes the active cruise control was an option that I don't have/need. I never actually use cruise control. The only time I use it is to check if it is still working. Most QX4 at dealer didn't have active cruise control when I was searching for my QX4.

[asnorton44]

2. The passenger window doesn't operate from the driver's door, only on the actual passenger door switch. Is this a known problem?

Maybe a bad switch pack, I have had to replace my two rear switches.

[ARKQX33V6]

Out of habit I shut off all electric devices before I kill the ignition. The QX4 if like my 1997 kills the compressor when starting and when WOT as when you floor it., and when the ambient temperature is around 34F.

Windows are in parallel so it may be a bad switch or bad connection or the lock out is not releasing that window and it could be the alarm system

Plus what the others are advising

[Towncivilian]

Out of habit I shut off all electric devices before I kill the ignition.

I do the same.

I also suggest putting threadlocker on the power valve screws, the engine is potentially a ticking timebomb if you don't.

Check your in-cabin air filter; if neglected, it's likely disgusting by now. See here for a guide.

Definitely check transmission fluid level & condition. If it's brown, smells burnt, or has unknown service history, do a couple drain & fills a few thousand miles apart, or better yet, do a pan drop and then drain & fills.

[sowlerthjh]

Thanks for all your comments. The most important thing, along with fluid check seems to be the power valve screws.

If I took to to a garage do I ask them to replace the screws, or to put a threadlocker on the power valve screws?

What does the threadlocker do exactly, and is it something that a garage will know about?

[Towncivilian]

The power valve screws can slowly back out of their holes and possibly get sucked in by the engine, potentially causing severe engine damage. Replacing the screws is not a bad idea (since the original screws have been subject to heat and vibration; new screws will stay in their holes tighter), but either way, be sure to use some red (permanent) threadlocker as there is no reason to ever remove these screws for maintenance or other purposes.

I believe a Nissan dealer will charge you $300 or so to do. I'm not sure how much of that is parts and how much is labor - they may replace a couple upper intake manifold gaskets and the throttle body gasket simply because the FSM suggests to, but they are durable metal-backed gaskets so I'm not certain this is required.

[sowlerthjh]

Are these power valve screws also called Butterfly Screws? Should an independant garage be able to do this? Do Nissan/Infiniti dealers apply the threadlocker?

The problem I have is that being based in Dubai, many of the independant garages do not speak good English and I can't explain the problem to them. The Infiniti dealer will check them for around $300, but will there be any guarantee with that?

[Towncivilian]

Yes, they are also termed butterfly screws. Both an independent garage and the dealer can do this for you. From what some have posted about their experience with applying threadlocker, some have seen some sort of crusty material which could have been threadlocker, but either way, it's not worth the chance. I've not done this yet on my Pathfinder, so I couldn't tell you if mine had anything on them.

Pretty much the only thing you can do if you take it to the Infiniti/Nissan dealer for proof is to supply them with the three "required" gaskets and a tube of unopened red threadlocker, and ask for the old gaskets and threadlocker back when finished. Is that what you meant by "guarantee"?

[ottofalcon]

is this power valve screw an issue to the vg33e?

[Towncivilian]

is this power valve screw an issue to the vg33e?

Nope.

[sowlerthjh]

Thank you to all who have replied to this thread. I picked up the car about two weeks ago and it seems to be running perfectly! Three further questions though:

1. It has done 135,000 miles and the butterfly valves have never been checked, is this still necessary? If it has done 135,000 miles then surely the screws are secure?

2. Does anyone know how to change the climate control to celsius from fahrenheit?

3. I am in Dubai, and the car was imported from the US in 2008. The radio will only tune to odd numbers (e.g. 104.1 then 104.3 then 104.5 and so on). Is there a way to change this so it will receive even numbers as well?

any help very appreciated.

[QX4ME]

I am no expert but I think:
1. There is still a chance it happens; some happens earlier some later, on the random basis.
2. I doubt we can change from F to C.
3. I don't think it's changeable (unless change the entire radio receiver). Are all FM stations on even MHz, such as 104.6 MHz, 105.2 MHz and such in Dubai? In US, even if some radio receivers has 0.1 MHz intervals, If I remember right, there is no even number of MHz channel in the US.

By the way, the screw lock issue worries me again after I forgot it for years. I am generally handy but not that handy like some people can do lots of mods, even take the entire engine or transmission out for repair. Roughly how long doe it take to do it myself?

Thanks