Blocked Heater matrix

thanos.m · 2nd November 2020, 19:48

Hi all,
My heater matrix is getting really bad now only have warm air coming off just the drivers side passenger and rears have gone completely cold so it's high time I get this sorted. So I would like to know your suggestions on how to best tackle this. The car has had the heater matrix replaced a couple of years ago by the previous owner my guess is it was probably a duff used one clog up this fast. From my reserch so far a lot of people are in favour of flushing it in the car but on my v6 I cant see an easy way to get access to the heater hoses. On the hand it looks quite easy to get the heater matrix out of the car but I've read the horror stories of trying to seal it back up. Also would it be worth it biting the bullet and going for a new one ? Rather trying to flush this one only to have it clogging back up later down the line. Additionally, is there a way of doing it without draining the cooling system fully I can only really see the top hose that I could clamp. Lastly, should even bother trying to sort it myself all together or is it a job perhaps better leaving to a garage to sort ?

trikey · 3rd November 2020, 07:22

I have a very good used aftermarket heater matrix for sale in my shop.

Bullnose75 · 3rd November 2020, 14:30

Are you sure it's the heater matrix that is blocked ? I replaced my heater matrix with a brand new unit on my V6 when my heater wasn't working but it turned out to be the engine oil cooler that was clogged solid on mine and that was stopping a good flow of coolant going through the heater matrix

thanos.m · 7th November 2020, 17:53

I can confirm it's the heater matrix ordered a new oil cooler hooked it up left the car to warm up to 90c made sure the system was bled and still getting cold on the passenger side so I do have a blocked heater matrix unfortunately

SD1too · 7th November 2020, 19:40

Quote:

Originally Posted by thanos.m

... a lot of people are in favour of flushing it in the car but on my v6 I cant see an easy way to get access to the heater hoses.

By far the least problematic approach is to flush it in situ. Trace the flow hose back to the engine and disconnect. You'll probably have to do this from below. The return hose has a convenient connection on its route to the expansion tank. (I have to admit that I've never done this so please let me know if you have serious difficulty.)

Quote:

Originally Posted by thanos.m

Also would it be worth it biting the bullet and going for a new one ?

Only if flushing fails.

Quote:

Originally Posted by thanos.m

.. is there a way of doing it without draining the cooling system fully.

Draining the cooling system isn't particularly difficult. Go for it! Just remember to follow the MGR procedure for refilling and bleeding and you'll be ok. Use distilled/deionised water to prevent future blockages.

Quote:

Originally Posted by thanos.m

.. is it a job perhaps better leaving to a garage to sort ?

Definitely not. They'll tell you that your head gasket's gone!

Simon

thanos.m · 23rd November 2020, 09:58

As of yet I didn't have chance to get the heater matrix flushed but I'm staring to think that is not the whole side of the story now that weather is getting colder the car is struggling to stay at 78C° it many times drops at 75 if I'm on the motorway so I'm thinking my new thermostat is bad

COLVERT · 23rd November 2020, 17:02

Quote:

Originally Posted by thanos.m

As of yet I didn't have chance to get the heater matrix flushed but I'm staring to think that is not the whole side of the story now that weather is getting colder the car is struggling to stay at 78C° it many times drops at 75 if I'm on the motorway so I'm thinking my new thermostat is bad

It could be the thermostat however the fact that it blows hot one side and cold the other says the matrix is a definite problem. The thermostat will just add to it.---

Go sort out your spanners.---

SD1too · 23rd November 2020, 17:22

Quote:

Originally Posted by COLVERT

... the fact that it blows hot one side and cold the other says the matrix is a definite problem.

Quote:

Originally Posted by thanos.m

... the car is struggling to stay at 78C° it many times drops at 75 if I'm on the motorway ...

What are you using to measure these temperatures Thanos?

Simon

thanos.m · 24th November 2020, 17:44

I'm not saying that the heater matrix isn't blocked that for sure is but it's also but as colvert just adds to it. I use the onboard diagnostics I pretty much have engine temp on every long trip. Last long trip was on Sunday I went to pick up another v6 75 we had the temp reading on that one as well and dispite being 2C° outside that had no problem staying at 90ish mine on the motorway was dropping at 75C° and the heater was getting quite cool even from the drivers side. So a thermostat is on the way so once I have it I'll get all done at once

Saga Lout · 24th November 2020, 18:19

I've just unblocked a matrix that was hard to clear, I filled it half full of hot water, and then holding it between the pipes and wearing a thick glove I wafted a blowtorch over the fins. I found that with the water inside it cleared once it was boiling, you can hear it expanding rapidly and then the water pushes the crud through, repeat the process two or three times and the water becomes clear. It's made an old and very clogged matrix clean again.

2nd November 2020, 19:48	#1
thanos.m Avid contributor Rover 75 saloon Join Date: May 2019 Location: West Sussex Posts: 220 Thanks: 54 Thanked 41 Times in 26 Posts	Blocked Heater matrix Hi all, My heater matrix is getting really bad now only have warm air coming off just the drivers side passenger and rears have gone completely cold so it's high time I get this sorted. So I would like to know your suggestions on how to best tackle this. The car has had the heater matrix replaced a couple of years ago by the previous owner my guess is it was probably a duff used one clog up this fast. From my reserch so far a lot of people are in favour of flushing it in the car but on my v6 I cant see an easy way to get access to the heater hoses. On the hand it looks quite easy to get the heater matrix out of the car but I've read the horror stories of trying to seal it back up. Also would it be worth it biting the bullet and going for a new one ? Rather trying to flush this one only to have it clogging back up later down the line. Additionally, is there a way of doing it without draining the cooling system fully I can only really see the top hose that I could clamp. Lastly, should even bother trying to sort it myself all together or is it a job perhaps better leaving to a garage to sort ?

3rd November 2020, 07:22	#2
trikey Premium Trader Rover 75 Join Date: Nov 2010 Location: Devon Posts: 33,764 Thanks: 8,837 Thanked 14,831 Times in 8,030 Posts	I have a very good used aftermarket heater matrix for sale in my shop. __________________ Lest we forget..

23rd November 2020, 09:58	#6
thanos.m Avid contributor Rover 75 saloon Join Date: May 2019 Location: West Sussex Posts: 220 Thanks: 54 Thanked 41 Times in 26 Posts	As of yet I didn't have chance to get the heater matrix flushed but I'm staring to think that is not the whole side of the story now that weather is getting colder the car is struggling to stay at 78C° it many times drops at 75 if I'm on the motorway so I'm thinking my new thermostat is bad Last edited by thanos.m; 23rd November 2020 at 10:26..

24th November 2020, 17:44	#9
thanos.m Avid contributor Rover 75 saloon Join Date: May 2019 Location: West Sussex Posts: 220 Thanks: 54 Thanked 41 Times in 26 Posts	I'm not saying that the heater matrix isn't blocked that for sure is but it's also but as colvert just adds to it. I use the onboard diagnostics I pretty much have engine temp on every long trip. Last long trip was on Sunday I went to pick up another v6 75 we had the temp reading on that one as well and dispite being 2C° outside that had no problem staying at 90ish mine on the motorway was dropping at 75C° and the heater was getting quite cool even from the drivers side. So a thermostat is on the way so once I have it I'll get all done at once Last edited by thanos.m; 24th November 2020 at 17:47..

24th November 2020, 18:19	#10
Saga Lout This is my second home MG ZT and Rover 75, Join Date: Jul 2013 Location: Wigan Posts: 3,276 Thanks: 2,556 Thanked 2,685 Times in 1,037 Posts	Try this. I've just unblocked a matrix that was hard to clear, I filled it half full of hot water, and then holding it between the pipes and wearing a thick glove I wafted a blowtorch over the fins. I found that with the water inside it cleared once it was boiling, you can hear it expanding rapidly and then the water pushes the crud through, repeat the process two or three times and the water becomes clear. It's made an old and very clogged matrix clean again.

3rd November 2020, 14:30	#3
Bullnose75 Avid contributor Rover 75 Tourer 2.0 V6 LPG Join Date: Apr 2018 Location: Colchester Posts: 210 Thanks: 4 Thanked 50 Times in 39 Posts	Are you sure it's the heater matrix that is blocked ? I replaced my heater matrix with a brand new unit on my V6 when my heater wasn't working but it turned out to be the engine oil cooler that was clogged solid on mine and that was stopping a good flow of coolant going through the heater matrix

7th November 2020, 17:53	#4
thanos.m Avid contributor Rover 75 saloon Join Date: May 2019 Location: West Sussex Posts: 220 Thanks: 54 Thanked 41 Times in 26 Posts	I can confirm it's the heater matrix ordered a new oil cooler hooked it up left the car to warm up to 90c made sure the system was bled and still getting cold on the passenger side so I do have a blocked heater matrix unfortunately