The Nissan Path Forum Index The Nissan Path
The World Wide Nissan Pathfinder Owner's Forum
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Use Google to search TheNissanPath forums ->
Need some expert advice - not hearsay. :)

 
Post new topic   Reply to topic    The Nissan Path Forum Index -> Nissan Transmission FAIL
View previous topic :: View next topic  
Author Message
mattadamsmagic



Joined: 27 Mar 2016
Posts: 2

PostPosted: Sun Mar 27, 2016 7:33 am    Post subject: Need some expert advice - not hearsay. :) Reply with quote

Hey all. Just purchased a used 2012 pathfinder. I'm loving it!

48000 miles and doing great.

I bragged on Facebook about my purchase and two of my friends jumped in to inform me about the transmission failures. One of them was a Nissan service tech. I said - "according to the Internet forums, it appears the issue was confined to 2005-2010 models." He replied - nope. You need to still do the bypass.

He no longer works for Nissan and is working for Toyota.

Now - I have a few questions. I've searched high and low for the answers but I am not a car guy and perhaps I just don't understand everything I read.

My understanding is that the transmission fluid needs to operate at a certain temperature. It runs from transmission into some section of the radiator. It leaves the radiator and goes into the external trans cooler. It leaves the trans cooler and goes back into the transmission.

1) I understand how it gets cooled in this process - but if that's truly the path, how can it get warmed in cold weather if it just goes right into the cooler after being warmed?

2) Does the 2012 OEM radiator still have a trans cooler section in addition to the separate trans cooler outside of it?

3) Do I need to worry about coolant leakage in the 2012 model? My Nissan buddy seemed to think yes. I don't know why he'd say that if it wasn't true. He clearly believes it is an issue. But he could be wrong. I need a true expert here...because I've read "the Internet" and I know what has been parroted. I want to hear the truth. ;)

4) Regardless of whether I need to do it or not, is there a benefit to doing a bypass in a 2012?

5) Is there a need to use another trans cooler? Isn't the OEM one a separate entity if you do a bypass? I bought a good Australian model trans cooler that should work well if I want to add it. But i may just resell it on eBay if I don't need it.

I know I'll have more questions - but these are my main ones. Just trying to understand. Thanks for the help!
Back to top
View user's profile Send private message
smj999smj
Site Admin


Joined: 22 Jan 2012
Posts: 5362
Location: Prospect, VA

PostPosted: Sun Mar 27, 2016 8:23 pm    Post subject: Reply with quote

Well, first of all, you have the order of the transmission fluid path incorrect. The trans fluid exits the trans, goes to the auxiliary cooler in front of the A/C condenser, then goes to the radiator's integral cooler where it is warmed or cooled, as needed, before returning to the transmission.

The affected models are 2005 through 2010. Those are the models for which Nissan extended the warranties. We have had only a few 2009-2010 models report cooler failures on these forums and most of the failed units have been on the 2005-2007 models. We have not had any reports of failed radiators on the 2011-and-newer models. Cooler failures have only been reported on the genuine Nissan radiators (made by Calsonic) for those years listed.

That said, a cooler failure "may" occur on any radiator with an integral cooler, regardless of manufacturer, make, model or years. Those failures are pretty rare (the subject Nissan radiators not included). Transmission coolers and even engine oil coolers have been installed inside the tanks of radiators for decades and have proven to be a very reliable design.

I can't speak for your friend as I don't know him. I'm a former Nissan Master Tech and worked for Nissan for 16 years, but left in 2003. In those years, I've met some excellent, knowledgeable technicians at several Nissan dealers and I've encountered a few that I wouldn't let touch my bicycle, nevermind my car...and everything in between. I moderate these forums and NissanForums.com, as well as participate at NissanHelp.com and ClubFrontier.com when I get time. If someone on these forums had had a cooler failure on a 2011 or 2012 model, I'd love to hear from them!

As far as whether you should bypass or not, it's really up to you. If it were mine, I wouldn't worry about it. Many have bypassed and have had no issues, but I always recommend against it for those that tow heavy loads or live in areas that see extremely cold weather. Those that bypassed have found using the factory installed, auxiliary cooler to do a sufficient job of cooler and added a second, auxiliary cooler is not necessary.

Transmission oil temperature (in the trans pan) runs ideally in the 175-200 degree F. range and should not exceed 275 degrees. The converter outlet temperature should not exceed 300 degrees F. and this is the place where temperature should be monitored. Those that have monitored transmission fluid temperature that have bypassed the radiator's internal cooler and run just the factory auxiliary cooler typically report seeing temperatures in the 150-165 degree range. Transmission fluid should operate at a minimum of 150 degrees F.

The other thing about installing a second auxiliary cooler is that for approximately the same price of a quality, aftermarket trans cooler, one can purchase a new, aftermarket radiator, replace the radiator and retain the use of the radiator's internal cooler, which, being a liquid-to-liquid cooler, is far more efficient than an air-to-liquid cooler.

Hope this answers your questions! BTW, I own a 2006 and 2008 Pathfinder. I replaced the radiator on the 2006, first, and bypassed the 2008. About a year later, I got a good deal on a Koyo radiator and replaced the radiator in the 2008, as well.
_________________
2006 Pathfinder LE VQ40DE AWD, aftermarket radiator, Airlift 1000's, Bilstein HD rear shocks, Doug Thorley shortie headers and mid-pipes, Magnaflow 12580 muffler, aFe Momentum GT CAI w/ dry filter, XTP plenum spacer, Superchips Flashpaq tuner
Back to top
View user's profile Send private message Send e-mail
mattadamsmagic



Joined: 27 Mar 2016
Posts: 2

PostPosted: Mon Mar 28, 2016 5:15 am    Post subject: Great reply! Reply with quote

Excellent! Thanks so much!! I'm doing nothing. If it fails later, I'll chime back in - but apparently my risk is too low to be considered an issue. It's more likely I screw something up in the bypass and installation of a second cooler.

Two thumbs up for you!
Back to top
View user's profile Send private message
Kestral
Moderator


Joined: 12 Apr 2014
Posts: 689
Location: MA

PostPosted: Mon Mar 28, 2016 4:09 pm    Post subject: Reply with quote

Really well said SMJ fantastic explanation!
Back to top
View user's profile Send private message
Kestral
Moderator


Joined: 12 Apr 2014
Posts: 689
Location: MA

PostPosted: Mon Mar 28, 2016 4:15 pm    Post subject: Reply with quote

By the way I have a 2012 R51 Pathfinder also and I decided not to do the bypass. After reading extensively on the subject I could find no reports of a 2011 or 12 with a radiator failure.

On that note my friends 2009 failed at around 150,000 miles. I told him to bypass at around 60,000 but he decided not to listen to me.
Back to top
View user's profile Send private message
limal45



Joined: 26 Jun 2016
Posts: 2
Location: Saudi Arabia

PostPosted: Sun Jul 10, 2016 9:53 am    Post subject: transmissian problem Reply with quote

hi
3 times now while driving - shortly after setting off i accelerated gently but nothing was happening and the 'slip' light was flashing - is this telling me the transmission is going to fail? after backing off and accelerating again the problem went away
_________________
Typhoons rule the sky
Back to top
View user's profile Send private message Send e-mail
smj999smj
Site Admin


Joined: 22 Jan 2012
Posts: 5362
Location: Prospect, VA

PostPosted: Mon Jul 11, 2016 3:08 pm    Post subject: Reply with quote

I can't say if you have a transmission problem or not based on the information given, but, the "slip" light is relative to the anti-lock brake and traction control system. I would have the abs codes read, which would require a capable scan tool to access, so, you may have to take it to an independent repair shop or dealer.
_________________
2006 Pathfinder LE VQ40DE AWD, aftermarket radiator, Airlift 1000's, Bilstein HD rear shocks, Doug Thorley shortie headers and mid-pipes, Magnaflow 12580 muffler, aFe Momentum GT CAI w/ dry filter, XTP plenum spacer, Superchips Flashpaq tuner
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    The Nissan Path Forum Index -> Nissan Transmission FAIL All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group