Coolant & CVT fluid change procedure

[Towncivilian]

I'm looking to change the coolant on my mother's '07 Altima sedan w/ QR25DE, 88k miles. Can I just drain and fill the radiator (obviously with genuine coolant + distilled water), fill the reservoir to "MAX" and keep checking it, topping off if necessary, til no more coolant is consumed? That's what I did with my Pathfinder and had no issues. I would basically be following the procedure outlined in the FSM, just without the vacuum tool. I'm not sure the coolant has ever been changed, and the overflow tank looks pretty low and the coolant in the overflow tank looks awful. Not sure what color it is, but I'll check that in a few minutes.

Also, what should I do regarding the CVT fluid? Should I bring it to Nissan and have them check the fluid condition with CONSULT first before doing anything? Anybody know how much that would cost? Neither maintenance schedule lists a change interval. I see the recommended procedure is to disconnect the cooler return hose and fill with new fluid at engine idle. This would take 11 quarts, which can be very expensive as I've read that the Nissan CVT fluid is $20/qt?

A couple other questions:

• At certain RPMs when accelerating there is a distinct "rattling" noise. Is this timing chain rattle, or? This happens with the Nissan OEM filter, and a Wix filter, so I'm pretty sure it's not filter related.
• Anybody had any luck with non-OEM oxygen sensors? Bank 2, Sensor 2 is bad per engine code. An OEM sensor is $151.

[Towncivilian]

OK, well, I had the dealer do the following:

• Coolant flush
• Brake fluld flush
• Inspect suspension (per parents' request)
• Check CVT fluid level and condition

There is nothing wrong with the suspension, but the tech lubricated a couple things for good measure (service adviser didn't specify what, and I didn't ask). There is a rattling noise during acceleration due to a rusted heat shield on an exhaust component. Not going to bother to fix it, and if it's anything like Nissan's fix for Pathfinders, it'll be some exhaust putty and a couple band clamps which will fail in 6 months again anyway. The CVT fluid is also okay.

One not-so-great thing to note: upon examination of the brake fluid reservoir, it was only filled halfway instead of to the max line, and the screen cap thing underneath the filler cap was not pressed into place at the halfway point of the reservoir. I wasn't going to waste the gas to go back and complain as it's a really minor thing, but it was a little irritating seeing that considering it was serviced at the dealer. I pressed the cap into place, and topped off the fluid to MAX. I'll be monitoring the coolant and brake fluid levels over the next few days.

[kerrton]

It's a misconception that a dealer is superior to other shops, this may or may not be the case, each shop is unique regardless if they are a dealer or independant.

Regarding the coolant flush, I can assure you that you got a much better quality of work from the Nissan shop than if you had done the work yourself due to the use of the power flush machine. A simple drain and refill will not get all the suspended load (i.e. crap, gunk) out of the entire system including the heater core, water pump, rad and hoses. You can achieve a good result without a power flush by continually filling and draining the system with water, running the car and using the water pump to circulate, then drain and repeat until you get a really clean drain but a shop power flush machine really does a better job and is much quicker. So good choice having this done at a shop particularly considering the high mileage.

Regarding the heat shield, I have an 08 Rogue with the same QR25DE and CVT, and the flimsy poorly secured exhaust heat shields have been a real annoyance. Any time I hit a big bump with my window down I hear an annoying metallic rattle - I've had my shop check and the heat shields are secured, but once they did find that it was bent and they bent it back using finger pressure so I'm sure the fix didn't last long. Also in the really cold winter months I get a loud rattle on hard acceleration that I suspect may be related to the exhaust and/or exhaust heat shields. My question is - is it a bad idea to remove one or both of these heat shields?

[Towncivilian]

Yeah, I was just trying to be cheap by seeing about doing it myself. But whatever, I wholeheartedly agree a flush was necessary since the Altima should have had 2 coolant flushes/changes at its current mileage, but had 0 until yesterday.

I'll be swinging by the dealer today to pick up a part so I'll probably mention the brake fluid reservoir to the service adviser just for the hell of it.

I'm unsure about removing heat shields on something as low as an Altima, due to possible fire hazards (i.e. parking over dry grass, etc). Here's some discussion of removing heat shields on Pathfinders; short story is that nobody has had any issues with them removed, but obviously a Pathfinder sits higher than an Altima, so things may be different.

[kerrton]

Thanks a lot for the link, I've been looking for a thread like that!

[Towncivilian]

Glad you found it useful.

I spoke with the service adviser earlier today and told him about the fluid reservoir, he said that it should have been filled to max and the screen cap in place when it left the dealership. He said a possible cause was air leaving the master cylinder, thus lowering the fluid level. He said he'd notify the tech who did the job so it wouldn't happen again. Dunno if that really is a cause, but anyway I'll check the fluid levels again when the Altima's back home and report back with my findings.

[Towncivilian]

Jeez, this section gets a whole lot of activity.

Brake & coolant levels are still spot on at MAX, so Nissan's work is satisfactory. Now to think about replacing that downstream oxygen sensor causing the MIL...