Anyone changed their HEATER MATRIX???

chinaone

Member +
Right, this is just the wrong time of the year. Started my car this morning, i can hear water dropping inside the car. I was hoping that my guess was wrong.
And it had to be the fucking matrix.
So now i wanted to know how to change this fucker?
Read something before saying that you have to pull the whole dash out...
any other ways doing this? links etc?
 

Jay

Admin
Yeah.

I usually end up tackling any local matrix repairs. Basically remove dashboard, disassemble heater system, remove heater box, replace matrix and rebuild.

EP91 is handier than EP82 thanks to the design of the matrix connections.

As a quick fix you bypass the matrix to remove it from the heater system. Find the inlet and outlet pipes that carry coolant from the engine bay to the heater matrix. This is them at the back of your engine bay:



And loop them together securely. It'll mean no hot coolant will circulate through the heating system in the cabin but the engine will function normally and be safe to use. This will keep you mobile.

It's important to do this incase the matrix suddenly dumps several litres of boiling fluid into the front footwells...

Now, just to give you a heads up, the next picture is only to show you what the heaterbox is and it's position behind the dash. Do not shit yourself as the interior doesn't need to be stripped to this extent!

You are aiming for the centre box in the middle of the bulkhead:



Closer look:



Even closer:



It's a case of removing the matrix from the heaterbox and fitting a new one. You can normally do this by dropping the dashboard forward and cursing at the heater system heavily. Here is the carnage of an EP91 replacement:






After removing the heaterbox, split it and replace the leaking unit.

Hope that offers a heads up and doesn't scare you too much mate. It's just a case of being calm, methodical and remembering where all the bolts go.

Jay
 

cue

Member +
no other way but to strip the whole dash mate... bypassing will disarm the interior heater system, and at this time of year i think is the wrong thing to do.:confused:
 

Jay

Admin
Good point - Bypassing the matrix is only a short term measure to keep you safe and mobile.
 

chinaone

Member +
Oh my days, thanks Jay for this info.
I can see water dripping out off the box behind the glove box, whats that box than? the water coming out off a hose end sort of thing??
 

Aga

Member +
good thing if you have air con is that no coolant will drip into the cabin, the coolant will run to the road because of the hose that exists that lets moisture off the air con get out. one thing that made me notice my heater had gone was coolant fumes coming out of the air vents in the cabin.
 

Adam_Glanza

Member +
when mine went the car turned into a sauna, steam just billowed out from the screen vents.
exactly what happened to me only 2 weeks ago, i had water coming out onto the carpet as usual, put the aircon on to try and dry out the water and boom out it came like a steam train, steamed my window up completely and went totally nuts.

car was starting to overheat due to lack of water so had to stop.

definately have to take off the dash and if your no mechanic its a real pig of a job, wouldnt even try to attempt it tbh.

also i would take it to a heater specialist to get the matrix as one from toyota was 300 quid
 

Jay

Admin
Oh my days, thanks Jay for this info.
I can see water dripping out off the box behind the glove box, whats that box than? the water coming out off a hose end sort of thing??
Gravity will mean the water runs down the fins of the matrix core and into your heating system. It will then run to the lowest point and leak out. That appears to be the passenger side footwell from what I've seen in the past.
 

Big_Daddy

Member +
What car in the pic is that heater matix from? Is it similer to GT ep82. plus location wise. My giving cold air so thinking shall i give it a shot.
 

Jay

Admin
What car in the pic is that heater matix from? Is it similer to GT ep82. plus location wise. My giving cold air so thinking shall i give it a shot.
The red car is an EP80, it's the same as an EP82. I would check all the other possibilities first as there is a lot of work in a matrix replacement.


Take off steering wheel.

Continue taking off parts until you reach firewall.

:)
Wrong lad. A direct path to the heater matrix does not require everything stripped out to the firewall.

:)
 

Jay

Admin
Whats the easiet way to fix the heater matrix, once out, do just flush it and stick it back in?
Think of it as a radiator. (Which it basically is)

Repair or replace as required.

If the core is blocked up with corrosion or is leaking you can get it refurbished by a local radiator repair shop. The cost locally is £70-ish but mainland UK should be cheaper.

It is a copper core in the EP82 which is easily worked on. The EP91 uses an aluminium unit which means some radiator shops will not touch it. New from Toyota there cost circa £300 new BTW so a refurb is a good option.
 

Jay

Admin
Remove glovebox and drop down the box directly behind it. This will give you access to the heater box and matrix. If you place your hand on the matrix can tell if it is blocked (luke warm) or working (hot as the coolant flowing through it).

You can disconnect the inlet and outlet hoses on the bulkhead (see the bypass pic above) and flush then reverse flush the unit until clear. I would advise using hot water and plenty of flushes to get best results.

If this doesn't work then the core could be badly clogged at the bottom and the coolant is not circulating through the whole core. That will indicate a repair or replacement.
 

Big_Daddy

Member +
Just to ask jay, to remove the heater matrix, do i HAVE to remove the steering wheel?
plus is the speedo clsuter bolted to chassis, if remove all the bolts for the speedo, would the dash just lift up leaving the speedo still there?Im find it hard removing the speedo cable and connectors behind the speedo. JUst need some short cuts.
 

Jay

Admin
Just to ask jay, to remove the heater matrix, do i HAVE to remove the steering wheel?
plus is the speedo clsuter bolted to chassis, if remove all the bolts for the speedo, would the dash just lift up leaving the speedo still there?Im find it hard removing the speedo cable and connectors behind the speedo. JUst need some short cuts.
That's one hing I can confirm mate - there are few shortcuts with this one.

The instrument cluster must come out. The dash is bolted to the carrier bar behind it.

You can remove the drivers seat and drop the steering column to the floor. This allows you to leave the steering wheel in place. Handy if you have an airbag to avoid. :)

The next poor soul who needs one done over here will form the basis of a tutorial/photo guide.
 

Big_Daddy

Member +
My car is parked up, so i will start the stripping of the dash in the next day or 2. Ill add a photo guide if you want me to?
Anything i should watch out for or be carefull when stripping?
 
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