About to be new owner, radiator question

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jontyrees
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About to be new owner, radiator question

Postby jontyrees » Sun Oct 21, 2018 11:17 am

Hi All - I should be taking ownership of a 2010 Pathfinder tomorrow, and I have a question about the infamous radiator/transmission issue, The truck I'm buying is in pristine condition - 56k miles, ultra clean, all maintenance records with receipts, brand new tires that cost $1300, new belts, just had it's 50k mile service at the local Nissan dealer. But everything else is original - including the radiator. It's been scrupulously maintained, but I would like to preempt any radiator/transmission problems. Question is, should I go with a full radiator swap, or does the bypass technique work just as well? The complicating factor is that I live in Tulum, Mexico - basically in the jungle a couple of miles from the Caribbean coast. Nissan has a huge presence in Mexico, I would guess they are neck and neck with VW as the sales leader here, so getting parts shouldn't be an issue - but if the bypass works, I'd as soon not spend extra $ on a new radiator if it's not necessary. It's hot here, and extremely humid - leather shoes get moldy in the closet humid - so would cutting out transmission fluid cooling be a bad idea? I read that a full swap is recommended for very cold weather, or for heavy hauling/towing, but I haven't seen hot/humid weather discussed. It's not desert hot, high maybe 90 most of the summer, 80 in "winter".

Sorry for the long winded question - it's basically, should I replace the radiator, or will the bypass suffice?


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palmerwmd
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Postby palmerwmd » Sun Oct 21, 2018 1:55 pm

Hi Jony,

welcome to TheNIssanpath.
The 2010 model year is a bit tricky as some trucks had the new (safe) radiator and others didn't.

Here is a list of "good" and "bad" radiator numbers, from the Xterra forums (exact same engine/tranny combo as our V6 powertrains):

21410-EA200 [seldom referenced, but may have been installed in some very early 2005’s.]

21410-EA205 [2005 – either 2/09 or 8/09. Listed on some parts websites as P/N 21460-EA205. There is some confusion as to when these were used. Some literature states until 2/09 and other literature states 8/09. P/N IS ASSOCIATED WITH SMOD. ]

21460-EA215 [2005 - either 2/09 until 8/09, see above. Listed as discontinued and replaced by 21460-9CAOE on Nissan parts websites. P/N IS ASSOCIATED WITH SMOD]

21460-EA265 [production dates unknown other @Surf and Snow's Xterra built in 04/05 and my own Xterra built in 09/05. P/N IS ASSOCIATED WITH SMOD.]

21460-ZL11A [8/09 through 2010 model year, isolated reports of SMOD, however I have not been able to verify.]


21460-ZL31A [production dates unknown. Listed as discontinued on Nissan parts websites , no known reports of SMOD.]

21460-9CAOE [2011 – 2015 model years – no known reports of SMOD] This is the part number for the most current version as of 11/16.

I think one can be confident that the risk of SMOD is nonexistent with the 21460-9CAOE radiator, and probably also with the 20410-ZL31A radiator. It appears that there is some risk with the 20410-Z11A version, and the 21410-EA200, 21410/21460-EA205, 21460-EA215, and 21460-EA265 versions are ticking time bombs.



So check your part number. Its on the right plastic cover of the radiator.
If its one of the good ones leave it be.
if one of the "bad" ones I would replace the radiator.
This is the best practices solution as the bypass is known to rob some cooling capacity.

Not enough to make a difference for most but in your case it would be no question to repalce the Rad.
Last edited by palmerwmd on Sat Mar 23, 2019 12:52 pm, edited 1 time in total.

jontyrees
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Postby jontyrees » Sun Oct 21, 2018 2:35 pm

Cheers - I'm really looking forward to owning this truck! After reading a lot of the long thread on the issue, I had decided to just go with the bypass, but now you have me rethinking it again! My thought was that we won't be doing any towing, it's unlikely we'll carry heavy loads over anything but local distances, and traffic around here is light. The whole town is about 3 miles long! Avg daily highs in the hottest month are 88, 80 in the coolest month. It's super humid, but I don't think that would be a factor. Given my usage model, do still think a radiator swap is called for? I'd prefer not to drop another few $hundred if I can avoid it. I'm coming out of a 2005 Nissan X-Trail, kind of a RAV4 sized crossover that was never sold in the US, and it's been a total lemon.

Hopefully I have a "good" radiator!

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smj999smj
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Postby smj999smj » Sun Oct 21, 2018 9:28 pm

There was another number, 21460-9CA2E. These were used as replacement for many of the early radiators. Later manufactured units seemed to be okay, but some of the early ones have been known to fail. The bypass will work; the R51 Pathfinders made in the US come with an auxiliary transmission cooler that seems to be adequate for cooling for most that do the bypass. Since you don't live in an area that gets really cold, the warming ability of the radiator's trans cooler doesn't really play into affect. For me, with aftermarket radiators available for under $100, it just makes sense to replace any suspect radiators. Failures on 2010 models are pretty rare, but they do occur on some.

jontyrees
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Postby jontyrees » Mon Oct 22, 2018 7:19 am

Thanks - this is really helpful! If I were to replace the radiator, would the transmission fluid still go through any aftermarket radiator? It just seems like a bad idea to even take the chance of coolant getting into the transmission. I'd prefer to route the ATF outside ANY radiator, original or replacement. If there's not big advantage, why even run that risk?

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smj999smj
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Postby smj999smj » Mon Oct 22, 2018 11:11 am

The use of a cooler inside a radiator tank is a design that has been used for a long time. GM uses them to not only cool automatic transmission fluid in many of their trucks, but also engine oil. On the whole, they are usually a very reliable design and cooler failures are rare. However, around 2004, Nissan completely took over Calsonic, a company that had been making their cooling system, HVAC and exhaust systems for many years. For some reason, that's when problems occurred with their truck radiators. For the Pathfinder, Xterra and Frontier, it was a seal in the transmission oil cooler located in the bottom tank that failed. For Titans and Armadas, the lower radiator tanks were prone to cracking and leaking.
The updated Nissan radiators, the Nissan Value-line radiators and aftermarket radiators have not had the cooler failure issues of the 2005-2010 Pathfinders original, Calsonic radiators, so running transmission fluid through them as per Nissan's original design should not be a problem. That said, if you wish to not run it through, then just bypass it. Many people do. I did it for a while on my 2008 until I got a great deal on a Koyorad radiator for $50, then I replaced it and re-connected the trans cooler lines to it.

jontyrees
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Postby jontyrees » Mon Oct 22, 2018 1:43 pm

Thanks- great info

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palmerwmd
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Postby palmerwmd » Mon Oct 22, 2018 2:53 pm

jontyrees wrote:Thanks- great info
Dont forget to take lots of pics and post them for us here.
I am sure may members would be interested to see a Pathy in such a exotic ( to us) environment as you described.
:D

jontyrees
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Postby jontyrees » Tue Oct 23, 2018 7:28 am

palmerwmd wrote:
jontyrees wrote:Thanks- great info
Dont forget to take lots of pics and post them for us here.
I am sure may members would be interested to see a Pathy in such a exotic ( to us) environment as you described.
:D
Will do! One of our first off-roadish trips will be from Tulum to Punta Allen, along a rough trail road through the Sian Ka'an Biosphere Reserve. Check it out on Google - definitely exotic!

jontyrees
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Postby jontyrees » Tue Oct 23, 2018 9:03 am

Just checked the radiator - 21460 ZL11A. That's the one that's not confirmed to have problems I think. Which leaves me with uncertainty. Do we know if there's a definitive list of good/bad parts?

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smj999smj
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Postby smj999smj » Tue Oct 23, 2018 11:36 am

Nissan never put out a list of failure-prone radiators, which I would assume they did so for liability reasons. The list of part numbers of failure-prone radiators has been put together over the years through forums based on input from those who have had their radiators fail. Not all of the radiators with these part numbers experience the failure and some may never will. However, the cost of the damage that results when one does fail, especially when they ruin the transmission, is a lot (typically anywhere from $5000-$7500), so, it makes sense to bypass the cooler or replace the radiator as preventative maintenance to ensure the problem doesn't occur. Most of the reported failures are on 2005-2006 models, usually with 21460-EA215 and 21460-EA265 part numbers listed on the radiator. The number of failures steadily declines as the years progress through 2010, however, I have heard of a couple of people with 2011 models and the 21460-ZL11A radiator report that their coolers had failed, as well. The failure-prone radiators were thought to be limited to the 2005-2010 models based on the extended warranty that Nissan created for radiators of those model years. So far, I have not heard of any cooler failures on the aftermarket radiators, including the "made in China" Ebay radiators, of which I have one in my 2006 Pathfinder that's been trouble-free for the last 6-years.

jontyrees
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Postby jontyrees » Tue Oct 23, 2018 12:44 pm

I have contacted my mechanic (who I know all too well from the endless issues with the Nissan X-Trail I have been driving), and he is familiar with the radiator issue, and the fixes. He will be doing the bypass for me Thursday or Friday. If I was back in the US where labor is expensive, and I had tools, I might have done it myself, but here it should be cheap,and he has all the lifts and other tools necessary to get under the truck. Down the road, I'll replace the radiator, but for now, this should be fine - I don't tow, and I'm not going to be running sand dunes any time soon! Thanks all!

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Postby palmerwmd » Tue Oct 23, 2018 5:11 pm

jontyrees wrote:I have contacted my mechanic (who I know all too well from the endless issues with the Nissan X-Trail I have been driving), and he is familiar with the radiator issue, and the fixes. He will be doing the bypass for me Thursday or Friday. If I was back in the US where labor is expensive, and I had tools, I might have done it myself, but here it should be cheap,and he has all the lifts and other tools necessary to get under the truck. Down the road, I'll replace the radiator, but for now, this should be fine - I don't tow, and I'm not going to be running sand dunes any time soon! Thanks all!

TheNissanPath at your service ! :D

jontyrees
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Postby jontyrees » Mon Oct 29, 2018 11:09 am

Just dropped off the truck with my mechanic. He was pretty insistent that the way to go is to add an external atf cooler kit, in front of the radiator. He said that the stock external cooler is "not enough", and since the kit is about $60, and his labor is very reasonable, I'm going with his suggestion. That's actually the solution I'm most comfortable with - keeps the atf completely out of the engine coolant loop, adds cooling capacity, less than $100. What's not to like?

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Postby smj999smj » Mon Oct 29, 2018 11:30 am

It's fine as long as it doesn't over-cool the trans fluid. The idea isn't to make the trans fluid as cold as possible but to keep it within the ideal temperature range. Auto trans fluid is best run between 175-200 degrees F. It should never be operated continuously with the fluid below 150 degrees. Those that have bypassed, run just the factory trans cooler and have monitored the trans fluid temperatures typically report temps around 160-165, which is a little on the cool side but acceptable (acceptable meaning it won't hurt the transmission). Hence the benefit of the integral cooler of the radiator. It's better equipped to maintain the fluid temperature in the ideal temperature range, not only cooling the fluid but also warming it, as needed. Liquid-air coolers are also more efficient than air-air coolers. Personally, given the temps reported, I think the second cooler is unnecessary, but it's not my money! You can get a new radiator for practically the same cost as the cooler kit!

https://www.ebay.com/itm/Radiator-For-N ... :0&vxp=mtr


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