mikeyen

1996 Maxima, 186k miles, in very good shape.

A few days ago, I launched this task. I was coming home from the local hardware store when I noticed vapors coming out from under the hood. Look at the temp gauge and sure enough, it was overheating. Turned it off, and immediately found the problem: The heater hose union on the firewall had disintegrated. Easy to fix, right?

Well, the two pipes that lead into the firewall were in the same state. I disconnected the house from the firewall, and the pipe to the heater core also fell apart. I'm just really glad most of this happened in my driveway instead of on the Yolo Causway on a rainy day, for example.

I read around here, and found that there were two basic ways to do this job: Drain the A/C, and everything can be done with the cooler box out. I didn't want to drain the A/C, so I chose the alternative method, removing the dash. Basically, this is the way AllData/FSM want you to do it, and they say 5 hours. I don't know anyone who could do this job in 5 hours.

My heater is now all the way out. I had to mostly remove the crossmember that is behind the dash. I saw no other way to do it. Once you get that heater all the way out, removing the core is easy.

My question: Should I replace the core too? The main thing on this job is the labor; the pipes are only about $20 each. I see that the dealer core is nearly $300. Ouch. I can put an after-market into it for anywhere between $40 and $80. Are those any good, or am I better off putting what I have back into the car?

This is a very involved job. My mech was willing to go along with 5 hours -- about $500 in Sac. Had I known how challenging this task is, for $500, I'm not sure I'd do this job twice.

Here's some advice, though: To remove the passenger-side airbag, use an air ratchet. I had mine off in 2 minutes. Too bad for me it took me 2 hours to think of that idea. Yes, I am a doofus. What makes you ask?

DennisMik

iTrader: (2)

The first time I took my dash out, it probably took at least 2 hours. A month or so later I helped a friend take his out. He'd never done it before. With the 2 of us it only took about 20 minutes. If I ever have to do it again, it's no big deal.

I started to take the big white air box off that holds the heater core, but when I realized that wasn't going to let me accomplish my goal, I bolted it back on. Overall, it could be a 5 hour job to change the heater core once you know what you are doing.

As for your heater core, only you can determine if the one you have is good. If you have been flushing the cooling system and refilling with fresh antifreeze regularly, then you are OK. If you haven't, which sounds like the case, change the heater core. You did rot out the connections after all.

mikeyen

I managed to get it all back together, and I think the car has fewer rattles than before I started.

As for those nylon parts getting brown and brittle, I really do think I changed the coolant a sufficient number of times. Between a radiator removal, a water pump, hose replacements, and routine maintenance, I'm pretty sure I've changed the coolant at least five times. For 17 years and 185k miles, I don't think that's abusive.

Anyway, no leaks now, and I'm happy I was able to get this back together. I should have replaced the heater hoses while I had them out; oh well, new ones are on the way. I'm going with the one-piece upper hose that Nissan used from December 1995 and up. Mine has the two-piece hose.

mikeyen

The 95+ bracket that secures the heater hoses to the firewall is no longer available from Nissan. Does anyone have advice for an alternative part?

Since the pre-95 part securely holds the lower hose, I'm thinking of simply zip-tying the new-style hose I'm installing to the lower hose and calling it good. The pre-95 bracket is unbelievably expensive, by the way.

Trini Boom

iTrader: (5)

Also, the heater core hosesare no longer available from Nissan. I was thinking of creating a thread with all the discontinued items.

mikeyen

For this instance, I don't know if that's correct. I successfully ordered the two pipes from a Nissan dealer to do this job.

There were 2 alternatives: Order the heater core from Nissan, and this includes the pipes and o-rings; or order just the pipes, which included the o-rings.

I hope Nissan continues to make the pipes available. If you have to order the core/pipe combo, that's a very expensive option.

Trini Boom

iTrader: (5)

Keep me posted on this. I ordered the heater core this past spring and it came with the core and the plastic nipples. The hoses when I tried to ordered were discontinued.