Help with no heating on 2002 Yaris please

[IKE35]

Hi, I picked up a 2002 1.0 Yaris last weekend - it drives nicely and I'm just wanting to sort out some niggles.

The heater isn't pumping out any warm air. It appears to be a common issue with the Yaris of this vintage and I've looked at a few legacy posts on here but can't find one where the original poster has come back to confirm it's fixed and what the cause was!

I watched and followed a YouTube video on how to dismantle the dash/speedo and check to see the valve is moving when you turn the temperature dial (and dropped a screw down the back of the dash in the process :s) and it moves absolutely fine. The poster then went onto say that if the valve is okay check to see both 'matrix pipes' are hot as they are prone to blocking. Only one of my pipes is hot, the other remains cold. I attach a pic for reference.

Are these pipes the next thing to check? Are they easy to replace? 

Any help appreciated.

Thanks

 

 

 

[oldcodger]

Seems to be a common problem on the older Corollas as well.

Would think the best way to confirm a blockage is to look in the engine bay and  I expect you will find where those metal pipes pass though  the bulkhead you will find two rubber hoses which go to the engine.

If you disconnect those hoses by the bulkhead ( clamping them if needed ) and then attach two new bits of hose the the metal pipes so you can use a funnel or garden hose pipe to  flush down some water and see if it comes out or not.

In the Corolla forum there is a long thread about flushing the heater matrix and various potions some have used, a quick search should find it.

Two things you might also find, though the valve arm is moving the internals could be jammed  shut  or if someone has recently refilled the cooling system you might have a bad airlock in the heater matrix, disconnecting the pipes as above should also clear it.

 

 

[IKE35]

Huge thank you to you OC. I found the long thread which led me to a step by step guide on how to flush the heating matrix.

I need to go shopping now for some Mr Muscle.

 

[oldcodger]

You are welcome, hope it fixes the problem easily.  

Don't forget the rubber gloves and safety goggle, those cleaners can be nasty !