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Heater Core Flush?

14399 Views 14 Replies 5 Participants Last post by  Clint
Hey everyone. This is my first real post and pretty much why I joined. I'm hoping for some good advice as I keep my '07 Frontier for at least a few more years (cross fingers). Anyway, here is my issue.

Recently I started noticing the scent of anti-freeze. After checking things out, I discovered a leak around one of the heater core hoses (see pics). I don't have anything leaking in the interior of the truck. It appears to just be from that hose. So, a couple of questions:

1) Is it possible just flushing the heater core could fix my problem?

2) What exactly is that plastic connector that the rubber line is going into and the metal pipe going off to the right?

3) if that plastic part is some sort of valve, could it be blocked or malfunctioning and need to be replaced (instead of an issue with the heater core)?



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Are you saying that is what is malfunctioning and not the heater core (a blockage there) itself? If so, that would be a huge relief. That aluminum tube attaches to the firewall by just a couple of bolts. Looks pretty easy. What is the purpose of that whole piece?
I get that. I mean, why does it go through the plastic piece instead of just right into tubing that connects to the heater core? Does the plastic piece have some sort of other purpose other than just complicating things? LOL.
Will do. I'm just relieved that it probably isn't the heater core. When I call the dealer, what should I call the part?

Thanks for your replies!
Not sure what yr your Frontier is, but:
Are you running the original stock radiator...and IFF so, are you aware of the possible transmission-fluid/coolant cross-contamination issues associated w/ '05-'10? AKA SMOD?

Edit: I see you have an '07, if you're auto trans then you'll want to look into this/SMOD.
Shortly after I bought my '07 used, I read about that issue. I don't know if the original owner had already taken care of it or if I just got lucky. But, mine has never shown any signs of cross-contamination. (Cross fingers, knock on wood)
Check the top radiator tank for a Calsonic sticker. If it has any of these P/N's, the radiator is original and you should bypass the cooler or replace the radiator (if there is no sticker, it is likely aftermarket): 21460-EA200, -EA215 or -EA265.
Ugh...I just checked. It is a 21460-EA215. Guess I should consider a replacement. :frown:

Update on my original issue. I called a Nissan dealership that is near my work on Tuesday. They had one in stock...$57 plus tax! That made me happy. Swapped it out that night when I got home. Took about 30 minutes or so. Very easy.

Even though I couldn't see a crack on the old one, that must have been it. No more leaks! Thanks again for the replies and great advice.
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