5 replies to this topic

[Phil64jones]

Help please... 

So I think the heater matrix on my 1999 MPI needs replacing, as coolant just poured out into the centre console and steam filled the car via the windscreen vents! 

My questions are:

Is there anything else it could be/I should check first?

If it is the matrix, do I have to drain all the coolant (from the rad bottom hose) first, do I need to remove the heater as a whole (which also entails removing the centre console first) or can I get to the matrix with the heater in-situ??

Answers and any other tips/advice much appreciated! TIA.

 

[RedRuby]

As you suggest it is likely to be the heater matrix, but it is possible that it is one of the two heater hoses or the on off valve. It would be advisable to drain the system although I have heard of people clamping the two heater pipes on the left hand side. What ever you decide to do remove the two pipe clips, put a container underneath and remove the pipes from the matrix, there are two cross head screws on the left hand side after removing them the matrix will slide out, depending on your centre console you will need to remove it or could get away with just unscrewing and removing the left hand side panel.

As a second thought you could clamp the two heater hoses in the engine bay and disconnecting the pipes at that level, that would save you completely draining the coolant system.

[alex-95]

As above you can clamp the hoses and remove them from the matrix, it probably is the matrix but the tubes that attached to the matrix can corrode so may be leaking out of them. 

[buznout]

I had mine out two weeks ago as the heater valve had jammed. Make sure the heater valve is open then disconnect the two hoses that go into the matrix with a bucket under it to collect the fluid. This should drain enough coolant out to remove the matrix. While mine was out, I also pulled out the heater valve to fix it, replaced the heater hoses back into the engine bay and most importantly replaced the matrix fittings. Mine looked like they were going to fail at some point.. Maybe this is where yours failed?

 

Once the hoses are disconnected, the actual matrix just pulls out like a cassette so no need to remove the entire heater unit.

 

Edited by buznout, 29 January 2017 - 10:35 PM.

[Phil64jones]

Thanks everyone. Matrix is out (it was leaky) & a new one on order. I drained the coolant and intend to flush out...any tips?

[Steve220]

Reverse flush the rad (bottom to top). Another tip someone gave me was to refit the stat housing without the stat in it then flush the engine, letting the water come out the top of the cylinder head. Mine threw out loads of brown gunk then ran clear there after! You'll need to block the rad pipe off for it otherwise it'll just come out there instead.