I thought it might be fun to do a kind of ride-along as I bust my knuckles getting the leaking heater core out of my ’02 Nissan Frontier – for the same basic reason that it’s more enjoyable to watch the running of the bulls than to actually run with the bulls.
To get at the heater core – which is basically a small radiator that warms the passenger compartment via warm engine coolant that circulates through it (and a fan/ductwork that blows/circulates the coolant-warmed air into the passenger compartment), it is first necessary to wrassle out of the way a plastic box that contains the AC evaporator. Which means first disconnecting the AC lines that feed it at the firewall. They are located just to the left of the heater core inlet/outlet tubes.
Ideally, get the AC system refrigerant evacuated before you do this. This requires specialized AC equipment which you probably won’t have unless you are an AC technician/professional mechanic – so you’ll probably need to take the vehicle to a shop to get the system evacuated and the refrigerant captured/stored so it can be put back into the AC system once everything’s buttoned up again.
I have a buddy who is a professional mechanic, so I was able to swing by his shop before I did any disassembly, to get the refrigerant out of the system.
Getting the evap box out is one of those things. As in: Are you ready for pain? Are you ready for suffering? If the Answer is yes, then you’re ready for Captain Freedom’s workout!
Chiefly because there is very little room to work in underneath the dash – because the space is tight and because everything’s packed in really tight. The box is only held in place by a few 10 mm bolts and all but one of them are easy to see and reach. The one you can’t see is invisible until you move the trim cover on the passenger side of the center console out of the way. Then you can slip a wobble extender bar through the mess to get at the last bolt.
Don’t forget to remove this one before you try to wrassle the box out because if you do, you will probably break the black plastic box trying to wrassle it out while it’s still partially bolted to the rest of the ductwork.
On my Nissan, this isn’t all that bad – in that it could be much worse. All I had to do to get at the heater (evaporator) box was remove the glovebox, which involved nothing more than removing the six screws that held the box in place. In some other vehicles, Step 1 is something like: Remove dashboard . . .
Once the heater/evap box is out, you will be able to see the heater core, which is off to the left and directly behind the center console on top of the drivetrain hump. You will also be able to see the two black plastic tubes that screw into the right side of the heater core and route from there to (and through) the firewall, where – if you’re like me – you earlier disconnected the rubber heater hoses and spliced them together so as to stop the gushing Niagra of coolant into the passenger compartment and all over the carpet. The ethylene glycol steam bath is especially good for the skin. And probably your lungs, too!
These black plastic tubes can be reused – assuming they’re not cracked and that’s not why you have coolant gushing into the passenger compartment and soaking your carpet with oily green goodness.
But should you reuse them?
I ruminated about this for a few days prior to actually tearing into the truck’s guts. The cheap (and po’) side of my brain said: Save yourself the money! Reuse those things! Then the smart side of my brain – such as it is – piped up and said: Do you want to risk having to do this job again? I ruminated not much longer. The plastic tubes aren’t broken/cracked or leaking. But they are 23 years old. Plastic gets brittle as it gets old and these particular pieces of plastic are subjected to hot coolant and then cool off – sometimes to freezing, if it’s that cold outside (and it sometimes is). It does to plastic what the sun does to a woman’s face. See her at 23. See here again 23 years later.
So – I ruminated – what are the odds those 23 year-old plastic tubes will not crack/break or leak in the years to come? Do I ever want to have to deal with the blankety-blank heater core again? To save probably $60?
I answered myself and will take a trip to the Nissan dealer for a pair of new tubes – which I gather are made of metal rather than plastic, as they ought to have been 23 years ago. That’ll be first thing Monday – when the dealer’s parts counter is open for business again – and after that, it’s just a matter of re-assembly, which is much less aggravating than disassembly. Chiefly because now you know how it all goes together – having taken it all apart.
Once the new core (and tubes) are installed and the box is back in place and everything else is buttoned up, I’ll have heat again as soon as I reconnect those two hoses I spliced together when the proverbial dam broke a week or so ago. Then it’s down to my buddy the mechanic’s shop to get the AC charged back up.
And ready to go for another 23 years!
. . .
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Correction to my last comment, I might have replaced at least one heater core. I seem to remember pushing the inlet/outlet tubes through the firewall at least once haha.
I’ve had several heater cores go out and I just removed the heater hoses and plugged the inlets and outlets on both sides. Getting under the dash is a nightmare. I grew up in Hawaii so I didn’t need and never used the heater except for a few times. In my early working years I bought used cars and did everything myself. And I used to buy cheap bias ply retread tires that would last about seven or eight thousand miles. Goodyear among others used to sell them and I rarely had a flat, just constantly going to the tire store haha. Think I might have had a heater core failure on my wife’s 1990 Bronco II Eddie Bauer under warranty, which had a two year warranty back in the day of one year warranties. We even got Eddie Bauer luggage with the truck that my wife used for years travelling. We used that Bronco II to go 4 wheeling on the Big Island of Hawaii to go to the beach and the mountains including the summit of Mauna Kea several times. We went four wheeling to places so bad including in the lava fields, places that were so bad that we would never go back again. And we never got a flat on the original equipment Firestone ATX tires haha. I would wash that Bronco II on Sunday night and my wife would drive it to work on Monday morning. That was one tough truck. The only way you could tell is the tires were all torn up. Did the brakes complete on that thing three times every 40,000 miles as my wife was all gas and brake. I was the brake master. I told her to start coasting a little more haha. The Bronco II is a good memory but I still have my beautiful wife. They used to talk about the Explorers and the Bronco II being prone to flipping over but that never happened as my wife is an excellent driver. Only idiots flip cars over.
Nice! I’ll definitely be re watching tomorrow. I could only make it to “Gold anodized bolts”
(Zinc plated steel machine screws) or tomatoe
Best advice I ever got? “If you’re in that deep, do it right.”
I have a 1990 Jeep Wrangler. That was the easiest heater core I every replaced.
It was also stamped “American Motors Corporation” on it. Its now a museum piece in my garage.
Hi Owen!
Glad you kept the Wrangler. Replacing the heater core in my old Nissan pick-up isn’t that bad – compared with how bad it is to do this job on newer vehicles!
Good luck, Eric. I’ve done a heater core replacement in an old car of mine. It took me a whole week while messing around in the evenings after work. The entire dashboard had to come out, down to the firewall. It was also surprising to see the damn thing be partially made from plastic, and it failed at the interface of plastic endcaps to metal radiator.
I sometimes wonder whether a car that’s more serviceable would actually sell. It’d cost a bit more to manufacture, so it’d be more expensive at the dealer, and “easy to fix” isn’t exactly a compelling feature except for a few nuts like us.
Eric, I feel your pain! Replacing heater cores is one job I never look forward to. Smart move to replace those plastic tubes and the seals. Look forward to happy driving with warm body and a clear windshield,,,onward
Amen, Peter – thanks for the encouragament!
Rockauto also has those plastic lines, and more.
I dread this on my Escape. Turns 22 in March. Sometimes there’s a hack available such as cutting out some dash supports, Dremel an access hatch in the plenum, etc. vs removing the entire dash.
The other one is 1991 Silverado fuel pump replacement. In tank, top mounted. Drop the giant gas tank, or unbolt the bed and lift up one side, or cut an access hole in the bed. At 70 none of the three are exciting. There is a 32 year old hard plastic bed liner that would come out prior to option three. Save the hands to just sign a repair shop check as option 4 most likely.
A common fault with Ford Rangers (mine was a 96) is the cheap plastic blending door they install in the heater box. Sure enough, the shaft breaks after being used daily for 10 years which freezes the blending door in whatever position it was in at the time of breakage. The fix from the dealer…$50.00 part but $2,000 to remove the dash, evacuate and drain all the fluids. However, there are clever people out there not willing to be at the mercy of dealership recommended repair and extortion. https://www.heatertreater.net/
I don’t work for these people but just want to pass on fixes like this that really work (unless you are restoring a Ferrari Testarossa and want originality). This kit consists of a new spring-loaded blending door with stainless steel shaft, a Dremel bit and instructions. You cut the heater box just in the right spot, cut the remainder of the old door out, slip in the new door and tape in the cookie from the heater box. Took me 2-hrs and saved me lots of $$.
Sorry for your pain Eric. Been there, done that, and I never want to again. Like others have said, I would pay a fair mechanic to do it now if I had too. But I take car ownership/use differently than most. Part of my reasoning is what you dealt with. The newer way of plastic everything is very bad for long term reliability. They just don’t last like metal does, and they all do it, plastic everything. It’s way worse now too with plastic engine parts. I have my doubts that todays cars will be on the road in 10-15yrs.
My son’s heater core just went (a 2019 with 110K miles), and he knew that the job would be egregious, so he paid, it was …………………. $3000………………. wow. Even our great family mechanic didn’t want to do it, and he prepared us for basically his cost to do it.
Again, cars are expenses, no way around it. I chose a long time ago to just pay up for new ones and let them get old and unreliable for others. Yes I pay more in the long run, but I look at it different. My justification is, I will work harder-smarter to pay for it. Basically, reliability and piece of mind are worth the extra cost to me. And since I am basically a salesman (aren’t we all to some point), I can’t show up at jobsites and meetings in a 10-15yr+ old vehicle. Tried it before, it doesn’t work. Most people are fickle.
I know many here will disagree with me, no problem. We all justify our own methods, it’s a human condition.
I find that showing up in nice much older vehicles makes a good impression. This is true with most men, most women are impressed with the shiny new trinket more so than the burnished old quality. This was a conundrum when I cared to impress women…
If you buy the new one, your income has to be higher, and your income taxes will be higher. For some of us, significant effort is expended to minimize that. But good on you, you have the freedom to spend on what you want. And if nobody bought new, I would have nothing to buy used.
And yes, new stuff is by design not economically repairable. Especially as cars have shrunk in size and bloated in complex features, things like heater cores necessarily get packaged in deep places.
Hi Chris!
My truck has almost all of its original mechanical parts, except the water pump. This heater core is the second OE component to crap out. The part was only about $60 and prolly about the same for the tubes (I will find out tomorrow) so only about $120 to do the repair and I doubt I will ever have to do it again (on this truck). The way I look as it, $120 is about a fourth of the typical monthly car payment so I am saving a not-small sum by fixing the truck, which will probably not need anything more than gas and basic maintenance stuff for another several years. Also, the truck saves me a fortune on insurance since can buy a basic, liability-only policy. Property tax – in my state – is also based on “book value,” so I “only” have to pay the state about $75/year for that. If I had a new truck, it’d be hundreds – if not $1,000 or more – for years to come.
My older rigs really are priceless when it comes to family finances. The 1991 Silverado still looks really nice, runs and drives great. The cost for just a used replacement would far surpass any parts costs including the engine and transmission. The only major repair was a trans rebuild in 2013 and while that was out they replaced the rear engine seal, ring gear, and starter. Total was about $3800, less than taxes and license for a used equivalent rig. Going on 12 years later: no leaks, no funky running, everything works.
I truly get it Eric. Different strokes. Just giving my example.
We run a 99 K2500 with farm plates that I paid $6-8K for about 10 years ago. And it came from AZ so it was in great condition. About 5 years ago it started coming apart. Brake lines, rusting through, etc….. and a lifter is going. So far it’s averaging $800-1000 per year to keep it on the road. I’ve asked my mechanic if I should get another one. He said I would just start over again. Keep it. I do some of it myself, but not brake lines.
Everything is questionable today, including “OEM” parts.
Last OEM GM part I bought was made in Taiwan. May
your parts be “fully functional” for a long time.
Also, I always replaced worm-type clamps with spring-type.
Got bags of them, gratis, from junk yards.
Capture and Reuse the AC refrigerant? Really?
1. Capture. Because the lying enemy-owned govt, chemical giants, and media say “climate change.” In the end, it ALL gets released into the environment, right? Leakage as cars age, and then mass release when cars are junked, right? I remember when these lies started, in the 1970s, and the hoax of the “manmade ozone hole” in the atmosphere that was going to kill us all with skin cancer.
2. Reuse? I’ve never known this to actually happen, and I don’t think I would want to reuse my old refrigerant. Is this really done, or is it said to cover legalities?
Hi Jim,
Yes, this happens a lot. Refrigerant is freaking expensive. On a five ton AC unit the system can take anywhere from 10 to 20 pounds.
R410a refrigerant is averaging about $60 a pound (actually I have seen as high as $100 pound). If one has to replace the compressor, condenser, expansion valve, or evaporator coil then the refrigerant needs to be recovered from the system. Once the unit has been fixed/repaired the system can be recharged with the recovered refrigerant saving the owner hundreds, if not thousands in new refrigerant costs.
There are things to consider like contamination (moisture getting into the system) that could make the refrigerant unusable and new refrigerant would be needed, but if you are able to reuse the existing refrigerant it is a money saver.
RG – love that you’re edjumacating the men folk on AC refrigerant recovery . . . So hot!
Your husband is a lucky man. And if I recall a HVAC guy.
Love it and laughing out loud
Hi BID,
I have ran a few calls with hubby over the years, usually a quick after hours/weekend service call. He can’t charge for me, but sometimes I am the parts/tool fetcher. Other times, I am just the seat warmer. 🙂
Actually, it was my father (a mechanical contractor) that taught me a little about A/C units. My ten year old self would sit next to him on the patio as he showed me how to hook up gauges and recover the refrigerant from our York unit. He also taught me how to handmake sheet metal (this was before the CAD/CAM systems that everyone uses today). I was absolutely horrible at it, but I could operate a Pittsburg machine and brake, but mainly I was reduced to picking up sheet metal scraps and sweeping the shop floor. 😉
Hi Jim,
Yup. I do it to save money. If I had just vented the system then I’d have had to buy refrigerant to replace it, adding considerably to the cost of the job. Lucky for me, my buddy’s a mechanic who owns a shop and has the AC equipment!
Thank you, Eric, and Raider Girl, for your replies. I did not know how many pounds, thus how much money was involved in a total replacement.
About eight years ago, I bought a can of refrigerant at Walmart and topped off my former sedan’s AC system. The price of the can was bearable. It gave me the WRONG impression that a full system recharge wouldn’t be a big deal.
Hi Jim,
On an automobile it is affordable. It would probably cost around $45 and take about 2-3 12 oz. canisters. I was referencing residential units….which the refrigerant is significantly more and does get quite expensive.
Respect to you Eric. This is one of those jobs I’d have written a check for.
I hope you have better luck with the Nissan Parks counter than I did the Toyota parts counter. They kept asking for the VIN and then would follow up with well why don’t you bring it in and we’ll take a look at it. Even though I gave them the exact part number I needed. It was all a ploy to get you to come in to pay whatever shop labor hours are now.
I tried to no avail to explain that it wasn’t my car, it wasn’t purchased here, and the person I’m working on it for is on a fixed income and can’t pay exorbitant shop fees. I finally got fed up and ordered what I needed off of Amazon.
Thanks, Mike!
The good news is – in re the parts – that eBay has ’em also. I’d prefer the Nissan OEM but if they give me lip, it’s eBay here I come!
Rock Auto is also a good source for parts, usually have some that are OEM.
You made the right call
Vehicles are designed to be readily assembled, NOT to be taken apart. Making it harder to perform what should be a fairly small job (replacing heater cores was quite common some 50 to 60 years ago, and EASIER, though rarely “easy”), if anything, makes it more imperative that the owner will have to take it to the “stealership” for repairs, as quite a few shops probably won’t touch it, which tends more to causing REPLACEMENT rather than repair.
And yes, replacing those tubes, provided you intended to keep the truck indefinitely, is a “no-brainer”. After 23 years, they’re probably not the only thing’s that’s aged, so why ask for it?
Vehicles built that way were so obviously designed to support the dealerships service grift. There is no other reason for barricading an essential component behind an entire dashboard CF.
Especially a component made of chintzy foil and plastic subject by design to regular freezing then instant boiling inside under pressure. A designed leak. Stupid salesman prolly sportin new V6 altima at the time keeps the bs flowin. . .dupes get lies.
Toyota. Toyota. Toyota. This is how they thrive. NO STUPID SHIT.
I can try to design such a stupid scenario but would fail due to my consciensce, honesty and common sense.
Just spent over 11 hours on Christmas day under such a car replacing a “poorly designed” alternator due to assbackward installation bracket threads.
Many dcades of avionics work and being same size as I was at 18 pays huge dividends.
The heater core on this particular vehicle is known far and wide among auto mechanics as the “terminator”. Replacement is FAR BER. Most people in cold climates choose to sell or junk the vehicle.
You can do it. Dont give up.
On my 2001 Camry we sold recently, heater core is easy to get to. On my 2000 GMH Statesman, removal of the whole dash is required. Prick of a job. My car is now 24 years old and nearing 300K kilometres. Your core is easy to get to. Lucky you.
Indeed, to5 –
I dodged a bullet! Truthfully, if this job meant taking the dash out, I prolly would have just bought a little plug-in heater and lived with it.