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Heater core ??????

  1. Please fill out the following to ask a question.

    MAKE: Toyota
    MODEL: 4 Runner
    YEAR: 2007
    MILES: 142000
    ENGINE: 3.6
    DESCRIBE ISSUE.... Driver side floor carpet is damp. When I looked under the hood I noticed the heater core location is on the driver side. How difficult is this to change or could this be a body plug that needs to be sealed? I'm assuming it is the heater core because the wife tells me there is a smell in the vehicle along with residue build up over the last month on the front window.
  2. @op, are you sure about engine size. Toyota never made a 3.6l. Only engines ever made in the 4 runners were a 4.0l or a 4.7l. That is unless we go back to 2002, were they had 3.4l's and before that some had 2.7l's.

    I would suggest using a dye and a pressure test FIRST AND FOREMOST to be sure. A dye can be bought with a UV light for cheap. It would sure suck to go through the hassle of removing the core just to find it was only water infiltration from a seal or rust. I think Mobile Dans 6hr estimate to be quite on the low side. Last one I did many years ago in a very well equipped shop took me a full work day and I still had to come in the next day for finishing touches, I probably ended up charging over 10hrs for that job.

    If you have AC, this is not a driveway job.

    If coolant level is not going down after all this time, and a pressure test shows no decline in pressure, or no UV dye traces present, I would not go through a core replacement.

    You can buy a UV pen light and glasses at walmart for a few bucks. See link.


    Dye can be bought at your local autozone or NAPA etc. See link.


    Pressure tester can be rented also. Call your local autozone to see if they have a kit for rent. See link.

  3. 2005 and 2007 heater core R and R is extremely similar if not identical. I could not for some reason get alldata disc for 2007 to work but 2005 works fine. Procedure is the same.

    See ACE pdf for procedure. Not something you want to be doing unless your real sure with proper testing such as mentioned in my previous post. ACE 1 pdf has 17 pages. Read carefully before throwing yourself at this.
  4. Also, be mindful the above PDF does not cover how to remove the whole instrument panel. There are SRS safety precautions to take care of also here. In my opinion, this is not a DIY'r job.

    In step 6 of the above PDF, they say to remove intrument panel safety pad assembly. That means the whole dash need to come out.

    Here is a pdf showing what that entails. If after all this, you still want to tackle this. I will try to help you the best I can in my not so often time off.

    See ACE2 pdf for instrument panel removal. See page 2 of ace 2 pdf. Note (safety pad assembly, that is again, as I said, THE WHOLE INSTRUMENT PANEL)
  5. Here is bolt and clip locations and procedure for instrument safety pad assembly removal. Again, this heater core replacement is well above a 6hr job, even for a pro. See ACE 3 pdf for clip and hidden bolt locations so you don't start breaking stuff as many do out of frustration.;)
  6. Never worked on one. But Make sure the heater hose clamps are tight maybe leaking and running down the firewall into the cab..
  7. Should read this article:


    Just talking about drinking the stuff, but breathing fumes into your lungs will cause the same problems, gets into your blood stream. Park this thing. Use to make heater cores out of brass, now all aluminum, even worse when made in China. With some vehicles, first item on the production line is the heater core, rest of the vehicle is built around it. Ethylene glycol has been around since the 50's, would think after some odd 60 years would come up with something better. Average death rate is about 5,000 per year due to antifreeze kidney failure.

    Cousin died from this driving an old beater to college, was a long painful death. Still have my Edelmann coolant pressure tester with three radiator cap fittings, this is when we had standards. A hand pump with a pressure gauge, pump it up to about 25 psi, and expect it to hold indefinitely. Latest question is where is that radiator cap?

    Took a male quick coupler to a shut off valve to a regulator with a pressure gague to a female quick coupler. Just buy the reservoir cap for the vehicle, they are all different now, tap a 1/4" NPT hole in it, and epoxied in a male quick couple, but they have kits for this. Hit it with about 30 psi, close the valve, should hold forever.

    Wasn't too bad of a job before FI vehicles, use to use screws, now all plastic that snaps together, when cold have to use a heat gun or will break those tabs off. Didn't have that many connectors, used a marker pen with a 1-1, 2-2 sequence so I would make sure all the connectors were put back together again, with FI have a ton of them. While I can snap them together with one hand, takes two hands to unsnap them, really have to watch my language. Center consoles are literately a PITA, can remove the two front seats first for some working room.

    Whoever came out with that evaporator box, should be shot, evaporator and heater core are in the same box, so have to recover the refrigerant first before that box can come out. But don't pay any attention to me, getting old and tired of all this BS. On some vehicles, cheaper to dump them if you have to pay to get this done.
  8. Yup