Help Needed - Water/Rad/Matrix question

[VIL]

Tech guys.... I need help

 

I have read a load of old threads and want to get to the bottom of my water issue before it becomes an issue!!!

 

Scenario:

Occasionally I can hear the water bubbling from behind the dash and have a suspicion that its a partially blocked Matrix?

So run it up today, and let it idle to see if the inlet/outlet pipes on the matrix get hot.

They both get too hot to touch although it could be my imagination but the top pipe (nearest the O/S) perhaps does not get quite as hot as the other?

 

Also ran the car with the rad cap off and it did seem to occasionally bubble and spill out water when revving the engine, but nothing happens on idle and the water level does not rise or bubble. Is this normal?

 

My third problem and a possible route cause is that I never seem to have any water in my plastic expansion tank. I can fill it up but after a period of driving its always empty. I dont think its cracked. The odd thing is that whenever I take the rad cap off the rad is always full with no loss of water?

 

Its been doing it a while and there is no gunk in the oil cap or water on the dipstick to suggest a head gasket problem, plus the dashboard gauge is always just below half way and it never overheats. The footwells are dry so I dont think its matrix problem and the rad was new only about a year ago with a lovely new shiny cap?

 

Any ideas what is going on.

 

If it needs a matrix flush where do you guys uncouple the pipes (at the matrix itself or off the pipes to the matrix)

 

Also if its air locked whats the best way to bleed the system?

 

Cheers

[absz]

if you can hear bubbles then its normally low water level that causes it. as air is sucked in via the expansion bottle if you're loosing water in the expansion bottle then there might be a leak somewere ? might be worth replacing the radiator cap before going any further. as they are known for failing.

[toyo rob]

i think you'll find this post by Ian most helpful;

 

http://www.mkivsupra.net/vbb/showthread.php?t=56619

 

or read through this one for 100% perfect way of flushing air out of the system;

 

http://www.mkivsupra.net/vbb/showthread.php?t=83646

 

i found that when running with the bottle 1/3 full squeezing the more accessible matrix feed pipe, the pipe with the sponge on it going across the top of the cover, produced bubbles for a quite a while.

also when i flushed the matrix i used the holts 2 step and that goes through the whole system, add it to the rad.

 

hope this is helpful

 

Rob

[VIL]

cheers Rob

 

I missed these posts on my search, so thanks for digging them out!

 

Its possible then I have a faulty cap. Odd though as it was a new Toyota one that came with the rad about a year ago?

 

Nice and easy to eliminate though! Thanks