sis004runner

is it hard to replace?

myyota

If its anything like an 86 4Runner you have to remove the complete dash to get to the heater box. its wasn`t hard but it was time consuming. It took me about five hours to replace the heater core in my 86 4Runner.

shaeff

I replaced the heatercore on my '94 4X4 Pickup. Link is in my sig, which should give you an idea of what needs to be done.

sis004runner

thanks for the replies and i will save your link. i just talk to the guy why he diconnected it but he said there was a box on the heater hose line against the firewall and he told me that was clogged. anyone know the name of that?

Workhorse

I would guess he was meaning the heater valve. It's a cable actuated valve that controls the flow of coolant into the heater core.

It looks like this

sis004runner

is that a dealer item only? im not sure i havent seen it. i'll find out when i find one at the wrecking yard. thanks

mcneil

i got the same probleme , front heater doesn t work ,but the rear one does . i looked at all those fuses , and all were good i even changed that sqare fuse behind the glove box ( ˟˟˟˟en cost 56 $) i finally decided to take off the front fan heater ,anyway as soon that i find a new heater fan ill post back later

Dras16

It is very time consuming! You can back flush the heater core by unhooking the lines and hooking up a garden hose to one of the lines and flush it out. That might help.

Cuba

Mine only ever seemed warm at best up front and kinda slow to get there too. I disconnected the hoses just a few hours ago and flushed it back and forth with the garden hose. There didn't seem to be any real resistance, though the coolant was quite dark-ish. Anyhow, it blows hot fairly quick now, just a few minutes from cold. The valve looks like it could go bad pretty easily. It would be the 1st thing I'd check (and was) as it's really easy to get at too. Careful not to break the old plastic though.

tsat

Just replaced heater core in 97 4-Runner. I had to completely remove dash and all components. It took me roughly 8 hrs. I would suggest digital photos of every part you take and marking your nuts and bolts. Also note if any electrical connections aren't used. I also took out the seats and thought it made it easier.

MKgitRdone

For anyone else coming late to the party, here's a pic of the heater core valve (circled in yellow) in 91 2nd gen 4Runner, (referenced earlier but no pics avail now in 2024). The green arrow indicates water flow direction (I THINK; please correct if wrong) . Lots of folks have had success reviving heater with REVERSE flushing heater core as described here (some use liquid dishwashing detergent, but I'd probably stick to legit Gunk coolant flush cleaners).. I like this patrons idea of flushing both directions a few times. (assume intercept the heater lines on the other side (bypassing the heater valve). MIght be wise to then ensure heater valve open (heater on high) and flushing just the valve with some gunk cleaner or SimpleGreen to ensure its clear too

).