About to have new radiator installed... bypass still advisable?

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Dwyck99
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About to have new radiator installed... bypass still advisable?

Postby Dwyck99 » Tue Aug 30, 2022 1:55 am

I have a 2008 V6 PF that I performed the tranny cooler bypass on years ago. My radiator just went bad so I am getting it replaced in a couple days. I ordered the Denso brand one off Rock Auto. Does this radiator still have a tranny cooler attached to it? If it does, is it supposed to have a design that absolutely prevents the SMOD and therefore I can undo the bypass and reattach the transmission lines to the radiator like factory? If this is true, what is it about the design of newer radiators for the PF that prevents this? I am not doing any towing, so if there is still an eventual chance of the cooler on the Denso failing and causing the SMOD, would I be better off leaving it bypassed? Or will I gain enough benefit from the tranny cooling to justify undoing the bypass(assuming the Denso is fail proof form SMOD)?

Also, I have never had any cooling problems prior to this... I will likely have the upper and lower hoses replaced since everything is exposed anyway, but is it advisable to replace the thermostat or leave it alone? And would you replace the belt eve if it looks good? Hoping the shop won't add a lot of cost for some other easy tasks since things are easy to get to with the shroud removed... anything else that I should seriously have then do since things will be exposed?


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palmerwmd
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Re: About to have new radiator installed... bypass still advisable?

Postby palmerwmd » Tue Aug 30, 2022 5:15 am

There is no need for a bypass with a replacement radiator.
The issue with the excessive failure rates of gaskets in the ATF heat exchangers inside the OME rads from 2005 to 2010 was unique to those parts numbers.

Every modern car has a similar design.
Install without bypass and you will have better cooling reserves for your transmission.

Cheers. :D

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Re: About to have new radiator installed... bypass still advisable?

Postby palmerwmd » Tue Aug 30, 2022 5:19 am

PS: As long as the raditor is getting replaced anyway, yes a new T stat is best practices.
BUT it MUST be a Nissan OEM Tstat.
This is a part where aftermarket is inferior and failure prone.

Consider getting the rear heater hoses/ inlet pipes done as well, if it does not break your budget ( at your vehicles age they will be failure prone now)

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palmerwmd
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Re: About to have new radiator installed... bypass still advisable?

Postby palmerwmd » Tue Aug 30, 2022 5:19 am

PS: Yes if the belt is original have that done as well, if it has bee replaced in last few years and looks good then no need.

Dwyck99
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Re: About to have new radiator installed... bypass still advisable?

Postby Dwyck99 » Tue Aug 30, 2022 9:15 am

The heater hose assembly comes with new inlet/outlet doesn't it? I actually replaced that assembly myself about 3 years ago and I seem to recall all that old plastic breaking and being replaced, but I can't recall buying the inlet/outlet separately. I understand the oem thermotstat, but do you feel the belt truly needs to be Nissan OEM or is there a belt I can get from a chain parts store like NAPA or Advance that is basically just as good? I am considering doing the radiator replacement myself, but I have seen some videos where it doesn't look too terrible, but then you read the comments and so many say that the videos do portray how difficult and time consuming it is to get the shroud and fan removed. If you or anyone else has ever done it on a PF, would you agree it is a much more frustrating/time consuming task that what one would imagine? Some of these people may have had more issues because it was done on Frontiers or Xterras, but not sure if that makes a difference. Any tips to make it easier?

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palmerwmd
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Re: About to have new radiator installed... bypass still advisable?

Postby palmerwmd » Tue Aug 30, 2022 9:59 am

Dwyck99 wrote:
Tue Aug 30, 2022 9:15 am
The heater hose assembly comes with new inlet/outlet doesn't it? I actually replaced that assembly myself about 3 years ago and I seem to recall all that old plastic breaking and being replaced, but I can't recall buying the inlet/outlet separately. I understand the oem thermotstat, but do you feel the belt truly needs to be Nissan OEM or is there a belt I can get from a chain parts store like NAPA or Advance that is basically just as good? I am considering doing the radiator replacement myself, but I have seen some videos where it doesn't look too terrible, but then you read the comments and so many say that the videos do portray how difficult and time consuming it is to get the shroud and fan removed. If you or anyone else has ever done it on a PF, would you agree it is a much more frustrating/time consuming task that what one would imagine? Some of these people may have had more issues because it was done on Frontiers or Xterras, but not sure if that makes a difference. Any tips to make it easier?
I have never done this job.
but folks tell me its more effort than on other vehicles.

I did change the radiator with a friend on another Nissan vehicle many years before.
It was 2 bloody amateur's, took us two hours.
One professional tech can probably do it in one

As for the belts, gates also has good reputation (i think they make the nissan OEM belts but am not 100% on it)

If u replaced some of the items there with the heater hose assmebly its likely not a issue for you.

Dwyck99
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Re: About to have new radiator installed... bypass still advisable?

Postby Dwyck99 » Tue Aug 30, 2022 12:28 pm

Ok thanks for the insight. One other thing... I just did the automatic diagnostic test where you turn the key on and push that button on the driver side door jamb 10 times and it runs through a series of tests for horn/wipers/lights and also tests if the radiator cooling fans comes on. The fan works fine with this test, but for some reason I am not seeing the fan kick on when I start up the car and turn on the AC. Shouldn't the fan automatically kick on as soon as you turn the AC on or is that the case with this car?What is the likely issue if it should have turned on?

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VStar650CL
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Re: About to have new radiator installed... bypass still advisable?

Postby VStar650CL » Tue Aug 30, 2022 12:34 pm

Dwyck99 wrote:
Tue Aug 30, 2022 12:28 pm
Ok thanks for the insight. One other thing... I just did the automatic diagnostic test where you turn the key on and push that button on the driver side door jamb 10 times and it runs through a series of tests for horn/wipers/lights and also tests if the radiator cooling fans comes on. The fan works fine with this test, but for some reason I am not seeing the fan kick on when I start up the car and turn on the AC. Shouldn't the fan automatically kick on as soon as you turn the AC on or is that the case with this car?What is the likely issue if it should have turned on?
The fan turns on according to engine temp and A/C pressure, the ECM only turns it on when necessary.

Dwyck99
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Re: About to have new radiator installed... bypass still advisable?

Postby Dwyck99 » Tue Aug 30, 2022 12:48 pm

Oh ok... I thought I had always heard that radiator fans on basically all cars kick on when the AC is turned on.... unless I am thinking of the engine cooling fan. Being that the radiator has no coolant in it currently, would that cause pressure to be low and be the cause if it not kicking on when I turn the AC on?

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VStar650CL
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Re: About to have new radiator installed... bypass still advisable?

Postby VStar650CL » Tue Aug 30, 2022 12:56 pm

Dwyck99 wrote:
Tue Aug 30, 2022 12:48 pm
Oh ok... I thought I had always heard that radiator fans on basically all cars kick on when the AC is turned on.... unless I am thinking of the engine cooling fan. Being that the radiator has no coolant in it currently, would that cause pressure to be low and be the cause if it not kicking on when I turn the AC on?
It's different because the primary fan on the R51 is belt driven, and under most circumstances that's all the engine and A/C need. The electric is strictly an auxiliary for high-load and/or high-heat conditions. On a car with all electric fans it's different, there would be no airflow at all for the condenser if it didn't at least kick the fan on at low speed.

Dwyck99
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Re: About to have new radiator installed... bypass still advisable?

Postby Dwyck99 » Tue Aug 30, 2022 1:32 pm

Ok gotcha, thanks I understand how the fans on this vehicle work now.

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Re: About to have new radiator installed... bypass still advisable?

Postby palmerwmd » Tue Aug 30, 2022 8:18 pm

Dwyck99 wrote:
Tue Aug 30, 2022 1:32 pm
Ok gotcha, thanks I understand how the fans on this vehicle work now.
TheNissanPath at your service Sir. :D

claytormatt
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Re: About to have new radiator installed... bypass still advisable?

Postby claytormatt » Tue Sep 06, 2022 6:32 am

I have a 2010 LE w/ 77K miles and the radiator and transmission were replaced in 2017 @ 53K

Is a bypass still needed ?

The dealer I too it to said they have never had a repeat after replacing the radiator and transmission etc.


thanks!

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VStar650CL
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Re: About to have new radiator installed... bypass still advisable?

Postby VStar650CL » Tue Sep 06, 2022 6:55 am

claytormatt wrote:
Tue Sep 06, 2022 6:32 am
I have a 2010 LE w/ 77K miles and the radiator and transmission were replaced in 2017 @ 53K

Is a bypass still needed ?

The dealer I too it to said they have never had a repeat after replacing the radiator and transmission etc.

thanks!
If it was replaced in '17 then it will have the fixed radiator version for sure. Nothing past early '11 had any SMOD problems we know about.


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