Nissan Murano Forum banner
Status
Not open for further replies.

Should you EVER replace the CVT fluid?

70K views 61 replies 25 participants last post by  geof3 
#1 ·
Just picked up the Mo from my mehcanic. Lots of work done on the 04 with 106,000 miles. New font tires, 4 wheel alignment, 4 rotors resurfaced with new pads, new accessory and alternator belt, oil change, 2 new wheel hubs, new air filter, spark plug check, differential check. About $1400 bucks worth.

Here's my two questions. First, my mechanic, who I would trust with my life, says he wouldn't do a CVT fluid change as a significant number of tranny failures occur after a fluid change, I don't tow anything, and of course you can't replace all of it anyway. Second, he says my plugs are gapped perfectly and show no wear or carbon buildup at all so he wouldn't replace them at about $18 a plug. What do you guys think?
 
#2 ·
Your mechanic is too honest!

I would listen to him on the CVT fluid change, but to have the plugs gapped he has to remove them and that is time consuming and expensive (3 of the plugs are on the back of motor and your mechanic has to take the intake manifold off to get to them). If he is doing all that work, might as well put new plugs in.
 
#3 ·
da39087 said:
Just picked up the Mo from my mehcanic. Lots of work done on the 04 with 106,000 miles. New font tires, 4 wheel alignment, 4 rotors resurfaced with new pads, new accessory and alternator belt, oil change, 2 new wheel hubs, new air filter, spark plug check, differential check. About $1400 bucks worth.

Here's my two questions. First, my mechanic, who I would trust with my life, says he wouldn't do a CVT fluid change as a significant number of tranny failures occur after a fluid change, I don't tow anything, and of course you can't replace all of it anyway. Second, he says my plugs are gapped perfectly and show no wear or carbon buildup at all so he wouldn't replace them at about $18 a plug. What do you guys think?
The CVT fluid advice sounds about right - though at over 100K the fluid could stand to be analyzed (and I'm pretty sure only the dealer can do that). Under normal (ie non-severe) service, fluid change isn't automatically required even at 100K.

I'd bet anything your mechanic only checked one (or possibly a couple) of the front plugs. Nobody in their right mind would check the rear ones on a Mo without replacing them. And, the only way your plugs are OK at 106K miles is if they have already been replaced. Standard plug replacement on the 04 Mo is 105K.

If you needed 2 tires (and it's likely those had already been replaced once), an alignment AND rotor resurfacing at only 100K, it sounds like that car has been driven pretty hard and the suspension/brakes have taken a beating. Though none of that work is totally unreasonable at that mileage - especially if you're good for another 100K now. I have NO idea why wheel hubs were needed, however.

Typical replacement interval for accessory belts is 40-80K. Air and in-cabin filters are 5 minute, do-it-yourself jobs for almost anyone - at about $20 each.

Overall, your mechanic doesn't sound too bad. Maybe a tad excessive on a couple of things, but they all have to make a living.
 
#4 ·
Thanks for the reply. The two tires did replace Kumhos 235,65,18's with new Kumhos and the back two wil replaced in about another 10k. Overall the Kumhos lasted about 35K. The front brakes have been replaced once before and that seems about right. Front hubs were for bearings going out. Sealed bearings you know. He may have only looked at the front three plugs. All he said was hes seem lots of this type plug last 200K so I don't know. As far as I know, only two things can happend to a plug. Gap change and fouling. He said the gaps were right.
 
#5 ·
In MHO, after 100k, you owe your Mo new plugs. Even at the cost of around $250. It's worth it for peace of mind for another 100K. The last thing you want is for one plug to break off a piece into a cylinder.

Again, just MHO

-Biggun
 
#6 ·
My MO is just a couple of hundred miles shy of 100k miles and I have noticed my MPG has dropped compared to when it had half as much mileage. I think I will consider plug replacement because of that, but if you are not experiencing any issues, then do not bother with replacing your spark plugs. I don't think they will break off into the cylinder but there is a slight chance that one of them may "freeze" into the socket if not replaced for a very long time.
 
#7 ·
da39087-

I wish I lived in your neighborhood. If I did I would be asking for your mechanic's phone number.

Your mechanic is right about the CVT fluid. 106,000 miles appears to be about the mid-life of the fluid according to various "CVT Fluid Deterioration Dates" reported by other MO owners.

Nissan recommends the plugs be replaced at 105,000 miles, which is probably the minimum expected lifespan. If your mechanic pulled the front plugs and believes they are fine then there is no reason to believe the rear plugs are any worse.

Your mechanic just turned away $500 in business. I doubt the average Nissan dealer would ever be accused of that. If you trust your mechanic and history has proved him to be honest and knowledgeable then I would go with his recommendations.

-njjoe
 
#8 ·
It cannot possibly hurt to change the fluids, and 100,000 miles is a lot to go without a change, regardless of whether it is "lifetime" fluid. It is relatively inexpensive to do preventive maintenance if you plan on keeping the vehicle for a while longer, so I would have no issues changing the CVT fluid at 100k. Remember, manufacturers tend to stretch their "regular schedule" maintenance intervals out to make it seem like the vehicle is maintenance free, but they only need to keep it running well through the warranty period. I can understand stretching it out if you plan to sell the vehicle or return a lease, but that just passes the potential problems to the next buyer.
 
#9 ·
Amen, joe.



Homer
 
#11 ·
evjm said:
An interesting thread...

Has anyone else heard that tranmission failures are more common after a fluid change? That's new to me.
Only if they put in the wrong fluid! Some mechanics are not familiar with Nissan's CVT transmission and put regular red ATF in it - thats a recipe for disaster. It is supposed to take Nissan NS-2 CVT fluid.
 
#12 ·
Yeah, I trust this guy as I have used him for years. The thing I like about him is his engine knowledge. He builds lots of racing motors and his team just last week set the world speed record for a stock dirt bike at Bonneville (http://www.wolbrinkrace.blogspot.com) A record that has stood since 1981 I believe.

Anyway, he says he pulls lot of NGK platinum plugs with 200K that are like brand new. He told me mine were gapped at 1.1MM and the electrodes were like new (at 106K). True, it can't hurt to replace them, but neither would replacing ever part on the car. Mileage is 18mpg and car purrs like a kiten. I'll take his word over Nissan's.
 
#13 ·
Eric L. said:
Remember, manufacturers tend to stretch their "regular schedule" maintenance intervals out to make it seem like the vehicle is maintenance free, but they only need to keep it running well through the warranty period.
With all due respect, you have no evidence to support this claim. Maintenance intervals are determined by the engineers who develope the specs for the mechanical systems.

Over the last few decades we have seen maintenance intervals on most automobiles lengthen considerably. This is due to advances in manufacturing techniques, metallurgy, and chemistry.

The use of platinum and iridium in it's construction, and the move away from leaded gasoline have played important parts in significantly extending the life of spark plugs. It was not that long ago that people would have laughed at you if you claimed to get 105,000 miles from your plugs. Now it is commonplace.

The same can be said of the CVT fluid. The CVT fluid is formulated to operate in an enrironment that is very different from a conventional tranny. A typical tranny has dozens of clutch plates, many of which are either engaging or disengaging with each change in gear. The MO has a single clutch that engages when the car is put into "D" and remains engaged until you move the selector to either "N" or "P". That significantly reduces the amount of contamination and heat introduced into the fluid. If you keep the fluid clean and cool (the CVT has two oil-to-water heat exchangers) the life expectancy can easily be extended.

There is nothing wrong with changing the spark plugs at 50,000 miles and the CVT fluid at 60,000 miles. It is just not required by the manufacturer nor necessary to ensure a long life of the vehicle. If it makes some drivers feel better, then that is fine. I just don't want to give our less-knowledgable members incorrect information about maintenance intervals.

Time to go and get into my rocking-driver's seat, strange-noise from the rear, hole-in-front-carpet, 4-year-old, 35,000-mile, still-fun-to-drive MO. :D

-njjoe
 
#14 ·
I actually agree with you Joe. If I didn't completely trust this guy, we wouldn't have anything to talk about. Most mo owners should get the scheduled maintenance on every component. Some mainetenance is scheduled as you know because of proven wear failure, and some is because of what might happen. I think the plugs and CVT fluid are in the latter. Wouldn't hurt, but might not help. Kinda of like buying insurance. The heck of it is, I wish I trusted NIssan more and I wouldn't even question this stuff. So it really does come down to who do you trust more, the guy who has taken care of you for years, who gets service bulletins every day, has never screwed me (I know something about cars), and never overspends me or the code readers at Nissan service.
 
#15 ·
I was at the dealership today dropping off my MO. The service adviser told me that the CVT is a sealed unit and should never require fluid change...

Then I asked him "...but you do check the fluid level, right?"

He said, no. It is a sealed unit so we cannot even check the fluid level.....He also had no clue about testing the CVT oil. He said he had never heard of that.

Needless to say, I asked for another service adviser to take over my business.....:mad:
 
#16 ·
Z,

It's pretty pathetic how unknowledgable some of these service managers are who just pretend to be experts. My guess is that some come from different car dealers/manufacturers and may know more about a Chevy versus your Nissan. In the end, always check anything a dealer tells you and always ask if the work could be covered under the manufacturer. Especially, if you feel that the problem should not have occured. Case in point, back in the day I had a pontiac firebird and the manafold bolds roughted out at 80K. I insisted with the dealer that it shouldn't have happen at any mileage. They ended up covering it under a GM good faith repair. Same goes true with my Mo's seat and its airbag that actiually was covered.

So far I would say that I have saved alot of money holding my ground on what I believed was right and fair.

-Biggun
 
#17 ·
I did a bit of research on CVT fluid change. I came up with two notable items, both stated and confirmed by Nissan techs:

1- Nissan recommends NOT to replace CVT fluid unless "CVT Fluid Deterioration Number" exceeds 210,000.
2- No tech has ever seen CVT Fluid Deterioration Number anywhere close to 210,000. One said he tested several high mileage Muranos and the highest CVT Fluid Deterioration Number he saw was less than 40,000, and that was for a Murano with 165,000 miles.

I guess this means under normal driving conditions, CVT fluid is a lifetime fluid.
 
#18 ·
zebelkhan said:
under normal driving conditions, CVT fluid is a lifetime fluid.
Thanks for this info, Zeb. It's good to hear and confirms what so many of us with Mo's have believed since we bought our cars.

`Under normal driving conditions' is the key phrase (IMHO, of course) when it comes to Nissan's CVT. Let's face it - Muranos are plushier Altimas with more utilitarian (larger), slightly higher bodies. And of course with a modified drivetrain including larger wheels and tires along with the cool, on-demand AWD (that so many of us in tough winter climates love). All these things explain why so many `older' women love the Mo so much.

While Mo's can certainly tow trailers and be driven in off-road (beach, mud, etc) conditions, they are still basically modified Altimas - NOT rugged SUV's.

By softening up the Maximas (now offering ONLY CVT's in them and no longer making a sporty version of what was once a true sports sedan), Nissan is now marketing that model to an ever growing older population segment as well.
 
#19 ·
So I'm being told by my dealer to replace my fluid. I live in Colorado where I drive in the mountains a fair bit, use engine braking in the mountains a lot, and generally drive hard. I've been researching this topic in this forum, the maintenance manual from Nissan (which I think is a pretty up to date copy), and a mechanic I trust (not at the Nissan dealership). I've come across some info that does not go contrary to this 210,000 number, but certainly needs to be taken into consideration.

Page CVT-69 of my manual states:

Check“CVTF DETERIORATION DATE”
CVTF DETERIORATION DATE More than 210000
: It is necessary to change CVT fluid. Less than 210000
: It is not necessary to change CVT fluid.
CAUTION:
Touch “CLEAR” after changing CVT fluid, and then erase “CVTF DETERIORATION”.

This is the CVT Fluid Deterioration Date. How this number is calculated is not stated, but at worst, this number is simply something to do with how long your transmission fluid has been in your Murano. At best this number is somehow calculated using how long the fluid has been there, how much you drive, and how hard you drive. I find this very doubtful and would suspect this is only time related. This brings me to what is stated on page CVT-15 which no one has talked on this thread.

Page CVT-15 states:

FLUID CONDITION CHECK
Fluid status | Conceivable Cause | Required Operation

Varnished (viscous varnish state) | Clutch, brake scorched | Replace the CVT fluid and check the CVT main unit and the vehicle for malfunctions (wire harnesses, cooler pipes, etc.)

Milky white or cloudy | Water in the fluid | Replace the CVT fluid and check for places where water is getting in.

Large amount of metal powder mixed in | Unusual wear of sliding parts within CVT | Replace the CVT fluid and check for improper operation of the CVT.


This seems to indicate there are more reasons to have to change your transmission fluid than just that number. Varnished state being the most common which is caused through things like stop and go driving and using your engine to brake. I've verified that my fluid (yes my Murano's fluid) is varnished, and I will be having it changed out. At least doing that will make sure I keep the new extended warranty that Nissan has granted on our CVTs. Not keeping up with maintenance may void any auto warranty if that is determined to be the cause of the failure.

YMMV, but it should be noted that there is typically not one reason to have to replace fluid. That number is not part of analyzing the fluid, just looking at a number that the diagnostic computer spits out when it's talking to the transmission's computer. This number should be reset if your fluid is changed. I've determined through the manual, my transmission fluid color/state, and a trusted mechanic that mine should be changed. If anyone is interested in the manual I'm reading, you can find it here: 2003 Murano Service Manual
 
#20 ·
Baoh-

It is not difficult for the engineers to develop an algorithm to calculate remaining useful life of the CVT fluid based on duty cycles, time, temperature, and load. Many cars incorporate this type of feature to calculate the replacement interval for the engine oil.

Out of curiosity, did you ever have a Nissan tech hook-up a Consult-II to determine the CVT Det Date? If so, what is it?

-njjoe
 
#21 ·
No, I didn't. I went off of what the actual service manual said which is that if your fluid is varnished, it needs to be replaced. While it is not terribly difficult these days for cars to have algorithms to determine fluid replacement needs for particular fluids in your vehicle, I do not for a moment believe the Murano has that for the CVT. It does not have algorithms for the oil fluid. It does not have wear sensors for the brakes. It doesn't tell you when your engine air filter or your in cabin microfilter need to be replaced. I'm sure if you speak with the engineers at Nissan that they will tell you to replace the CVT fluid as stated in the service manual. The manual gives 3 appearances that the fluid needs to be replaced under and 1 number. You should probably ask them how that number is calculated. The dealerships don't analyze the fluid to find that number. I suspect that the number is purely a self life number. As I pointed out in my last post, it's not CVT Fluid Deterioration Number. It's CVT Fluid Deterioration Date in the manual and on the computer.

BTW, I'm familiar with these algorithms and sensors. My BMW has all of that stuff, and sadly I love it because it's somehow easier to trust a computer to tell me when a potentially warranty impacting service is really due than a human being with conflicting interests.
 
#22 ·
Baoh said:
BTW, I'm familiar with these algorithms and sensors. My BMW has all of that stuff, and sadly I love it because it's somehow easier to trust a computer to tell me when a potentially warranty impacting service is really due than a human being with conflicting interests.
But it was a human being with conflicting interests that programed the computer. "Who is on first, What is on second...... wwwoooooooo"
 
#23 ·
zebelkhan said:
My MO is just a couple of hundred miles shy of 100k miles and I have noticed my MPG has dropped compared to when it had half as much mileage. I think I will consider plug replacement because of that, but if you are not experiencing any issues, then do not bother with replacing your spark plugs. I don't think they will break off into the cylinder but there is a slight chance that one of them may "freeze" into the socket if not replaced for a very long time.
I replaced my spark plugs at 80k miles, 3 hours and $100 in parts later, I've gained about .5 mpg according to the DIC, and about 1.5 mpg more by manually calculation. Put about 2k miles on them so far.

Most people would not notice the very slight lowering mpg's over time, and on this car the mpg increase after a plug change is rather weak lol.

By the time it hits the 105k interval, they'll have paid themselves off though. :D
 
#24 ·
I say: Change the fluid!

I am for changing the CVT fluid, at the interval recommended by the dealer.

When or IF the transmission fails, and would need to be replaced under the warranty, the last time the fluid was changed, will be the first thing the dealer will check, before snapping a new tranny in your MO.

So why shouldn't you spend $199 for a flush, instead of $4,000 for a replacement?
 
#25 ·
Re: I say: Change the fluid!

sev said:
I am for changing the CVT fluid, at the interval recommended by the dealer.
What interval are you referring to? The interval published in the manufacturer-generated Service Manual that calls for fluid replacement when the Consult-II diagnostic tool confirms the CVT Deterioration Date has reached 210,000, or the arbitrarily chosen xx,000 miles used by some dealers?

-njjoe
 
#26 ·
Re: Re: I say: Change the fluid!

njjoe said:

What interval are you referring to? The interval published in the manufacturer-generated Service Manual that calls for fluid replacement when the Consult-II diagnostic tool confirms the CVT Deterioration Date has reached 210,000, or the arbitrarily chosen xx,000 miles used by some dealers?

-njjoe
I am reffering to the Service manual that came with your car.
 
Status
Not open for further replies.
You have insufficient privileges to reply here.
Top