Just purchased an 01 Qx4, A few questions...

[netwreck94]

Hey folks,

New to the world of Nissan-Infinitis...just lucked out and found a 2001 Qx4 here locally (Jamestown NY) Black/Black with 150k. Lots of service history, 2 owners...price, $4,800. The only issue I've had so far is a problem with the heating/coolant, which I believe to be a thermostat to be stuck open. The truck takes a long time to heat up, and the farthest I've ever seen the coolant needle is a little over a 3rd of the way up...when I'm drving on the interstate at 70mph it goes all the way down to the "C". Went to my local dealer and they told me that it could be the thermostat, or something far more expensive having to do with the "outlet" and "control valve"? The part alone for the more expensive job was $125, plus 2 hours labor. Can anyone elaborate on what it is they're saying it could be? As far as I can tell everything points to a stuck open thermostat...and I want to avoid the $40 they'll charge me to tell me if its problem A or B. To replace the 'stat they've got the part at $24 along with 1.1 hours (I'm assuming the parts cost doesn't include the coolant refill). ...How much should I look to be spending to replace the stat with labor? I've got a couple independent mechanics that I use, but if the dealership is pretty close in price I'll just have it done there....

Also, while I have the car in for this, what else should I have done/looked at with the 150k mileage?

Thanks for the help

Evan

[coledog188]

I don't have any knowledge to share about the coolant issue, but I can say my temp gauge sits just below the mid point towards cool.

As for the 150k, since you just bought it (good price btw!) you should get an oil change (full synthetic high mileage), a transmission fluid change, and a transfer case fluid change.

Also check the flange on the exhaust in between the first and second muffler. It's the one right over the rear axel, has a tendancy to rust and break. A cheap muffler place can usually just weld it all back together for $20. I've had to do that with a 98 QX4, a 96 Pathfinder, and a 03 QX4 when I got them.

While getting your oil changed you might check your air filter as well. Changing the fuel filter won't hurt anything either, all of that will help your gas mileage.

[asnorton44]

How much should I look to be spending to replace the stat with labor? I've got a couple independent mechanics that I use, but if the dealership is pretty close in price I'll just have it done there...

It should take no more then 1.4 hours, for reference the part number is 21200-4W01B. Here are instructions if needed:

1. Remove under cover.
2. Remove suspension member stay.
3. Drain coolant from radiator.
4. Remove drive belts.
5. Remove water drain plug on water pump side of cylinder block.
6. Disconnect lower radiator hose.
7. Remove water inlet and thermostat assembly. (Do not disassemble water intlet and thermostat. Replace them as a unit, if necessary)
8. Install thermostat with jiggle valve facing upward.
- After install run engine for few minutes and check for leaks.
- Be sure not to spill coolant.
9. Reinstall any removed parts in reverse order of removal.


EDIT: The outlet and valve he is talking about is the water control valve and the water outlet housing.

[netwreck94]

I don't have any knowledge to share about the coolant issue, but I can say my temp gauge sits just below the mid point towards cool.

As for the 150k, since you just bought it (good price btw!) you should get an oil change (full synthetic high mileage), a transmission fluid change, and a transfer case fluid change.

Also check the flange on the exhaust in between the first and second muffler. It's the one right over the rear axel, has a tendancy to rust and break. A cheap muffler place can usually just weld it all back together for $20. I've had to do that with a 98 QX4, a 96 Pathfinder, and a 03 QX4 when I got them.

While getting your oil changed you might check your air filter as well. Changing the fuel filter won't hurt anything either, all of that will help your gas mileage.

I asked the owner that I bought it from what he ran in it and he said regular oil, so I simply replaced it with regular oil right away after I bought it....I've heard that it's not good to switch back and forth so I'm staying with the dino oil for now. I've heard the same about transmission flushes, that if they've never been done before (or as far as I know) that its not a good idea to do it since after flushing the old fluid it may uncover some issues that the old fluid had covered up...I'm assuming the same story for the transfer case? But please feel free to prove me wrong...I'm having the truck in on monday at a local indy mechanic who's doing the 'stat for just $100 which is a full $150 less than the stealership. So while it's there I'd be more than happy to have him do anything else that should be done while he's got the chance. Fuel filter was changed about 25k ago.

I've been hearing a little "puffing" from about the mid-point of the exhaust while idling...could this be that flange you're talking about? I'll have him weld it back up if so...

Any other input at what I should do at 150k is appreciated...shocked at how much truck I got for the money, this one is in amazing shape and was obviously well cared for.

Thanks again,

Evan

[asnorton44]

Yes for the transfer case just do a drain and refill. I did mine, requires 3.2 quarts.

[netwreck94]

Yes for the transfer case just do a drain and refill. I did mine, requires 3.2 quarts.

Will have him do that on Monday as well then...will do a search for which fluid to use and will try to just bring it with me Monday. As for the Tstat, I'm second guessing myself about it. I continue to see pictures of the temp gauge on these resting well below the "mid" point, mine does that when going slow or after I turn it off for a few minutes and turning it back on...but on the interstate at 70mph is usually drops almost all the way to "C" moving back and forth a few ticks in either direction. I'd hate to spend $100 that I don't have to, but I find it pretty hard to believe that the operation of temp gauge is normal...sounds exactly like a stuck open 'stat to me. Also, my coolant isn't showing in the overflow tank, but the radiator is full...could filling up the overflow to the "cold" line improve this fluctuation of temp range? Or is my initial diagnosis correct in that I should just have the thermostat replaced.

Again, Thanks...really liking this website!

[asnorton44]

You need synthetic automatic transmission fluid for the transfer case.

[alexf20c]

No you don't.

[Chuck Tribolet]

No you don't.

I agree. '01 PF FSM says:

"Nissan Matic “D” (Continental U.S. and
Alaska) or Canada NISSAN Automatic
Transmission Fluid*2"

and the *2 footnote goes on:
"
*2: DEXRON III/MERCON or equivalent may also be used.
Outside the continental United States and Alaska contact a NISSAN
dealership for more information regarding suitable fluids, including
recommended brand(s) of DEXRON III/MERCON Automatic
Transmission Fluid."

[asnorton44]

Okay gotcha I was going off what is listed on the AMSOIL website, Synthetic Multi-Vehicle Automatic Transmission Fluid (ATFQT). I take it synthetic is recommended not required.

http://www.amsoil.com/mygarage/ProductR ... NITI+QX4+L