FourRunner89

Hey,

I have two questions about my 89 4Runner V6:

1. I have some sort of auxiliary line coming off the water pump (or off of something near it) that is capped with a bolt. Not sure what this is, but it doesn't seem to be causing a problem. Anyone know what this is or what happened?

2. I smell coolant nearly all the time, especially if I am not in motion. It is pretty potent and burns my nostrils quite a bit, its strong. My mechanic can find no leak anywhere, so he told me to just keep an eye on the coolant level and watch the temp gauge. The smell doesn't come from the cabin vents, and I am not sure where to look for the heater core.

I don't see any coolant in the oil or oil in the coolant. The truck has a new radiator, water pump, thermostat (gaskets all new for pump and stat) and they are dry as a bone. Everything appears dry. The radiator pan is dry, etc.

Is this common? Where should I look? I was told by the last owner that the head gasket was done recently, and my mechanic didn't mention anything.

Terrys87

iTrader: (1)

Your heater core is on the inside of the cabin on the firewall. It centered or nearly centered on the firewall just above the transmission tunnel. If you are smelling it on the inside of the truck, I would suspect the heater core having a small leak. The little clamps that hold the metal hoses to the core are flimsy and the brass edge of the heater core is easily bent. I wonder if it wasnt replaced in the past and if the clamps arent installed right or they bent the edge of the heater cores pipe, that could cause a small leak.

Before I got into changing a heater core, I would check for any small leaks that could be getting on the engine while hot and somehow making its way into the cabin. Here is a link to getting the dashpad off and I have some more information about disassembling the entire dash to remove the core but will need to look for it. Link>>> https://www.yotatech.com/forums/f199...l#post51778558

This isnt all of the steps, but if you click on my avatar and then click on my statistics, look for all threads I have started. It will be somewhere in the two 4 runner builds or the 88 truck build. I will see if I can find it also later on today. Review the video/s and steps a few times befreo even starting, it will make a big difference for you.

Here is some more info I copied from one of my other builds. Some where I have tried to show how to disassemble the dash to replace it and see where I put it. It is a big job for your first time. I would want a full weekend to do it for the first time. Hopefully you dont have to go and replace the core but if you do this will give some help.

Copied...
The temperture has been dropping around here and Steve was saying that his heater wasnt working. He doesnt know much about mechanicing so I looked at it and said it must be a clogged heater core so we tried flushing it several times and got very little junk out of it. So then I tried to soak it with CLR. Trying everything to avoid from swapping heater cores. Nothing worked, so today he went and bought a core from Oriellys for $62 if I recall right.

Flushing wasnt going to fix this one and is the first time that I have ran into something like this. His truck doesnt have AC, and instead of having the condenser, it has a square tube in its place. The heater core was full of dust,dirt and debri. My guess is with an AC unit under the dash it would of blocked the debri from getting to the heater core, but with a square tube, the debri goes from the blower straight to the core. Flushing cant fix the outside of the core.

I have listed on one of my threads about how debri gets thru the cowl and on the passenger side it can get down to the blower and that is how you can get fan noise from debri getting in from the out side. I am going to do the following write up so as I can just copy and paste it to my 88 Runner build as I am trying to make it where someone that has questions, that maybe the 88 Runner build can help solve their problems. I refer to it alot myself.

Remove Speedometer Bezel
Remove Speedometer Assembly
Remove Lower Panel
Remove Glove Box
Remove Dashpad
Remove the hoses clamps under the hood. I find it easier to leave the hoses attached to the core and push the hose thru the firewall with firewall seals attached.
Unhook the 4 cables attached to the heater controls.

Here you can see I removed the White plastic cover and the side arms that support the dash and where your stereo will mount to.


When pulling the heater core assembly thru, pull it til the metal hose portion clears the firewall and slide to the right to clear the bracket and core where my fingers are pointing to.


Here is the Core Assembly. You will have 4 clamps on top that are held by phillips screws. Remove and slide the core up and out.


Seperate the pipes from the core. My replacement core didnt come with new seals or the c clips. Be gentle with these as you will need to reuse them. When you stick the old pipes into the new core (you use your old pipes) do NOT try to squeeze them with pliers to try and close the gap. The edge will bend and then you have to straighten it out. I found it easier to have someone to push the two pieces together while I put on the clip.


The oring you will need to reuse. I should of went to the store and got a new one, but we didnt have any leaks when done.


Here is the problem with this core. Steve wanted a new one in it. The old one was actually in great shape, so I will clean the outside and keep it for a spare. I am a cheapscape and can have a core out in 45 minutes, just because I have done this several times.

The first time I changed heater controls, it took me 3 hours. This is not an easy job for your first time but will add this post to my 88 build to try and make it easier for someone who might have to do this. I have some videos of other steps.

New one on left and clogged one on the right. First time I ever ran into a core like this.

Terrys87

iTrader: (1)

More videos, my videos are terrible, but it does show what you are getting into. I will edit this later and try to get it in order to the way it goes to disassemble the dash.


One tip I would suggest is to spray paint/ or mark them with different colors where and how the heater control cables lay in the dash and connect to the different pieces.

daz25

Thanks for the posts Terry, they've been really helpful.