Heater Matrix - direction please ... - Page 2

kaiser · 11th October 2018, 05:05

Glad it worked for you.
But a fill, with subsequent top ups, will always sort things out.
It is a tricky one to fill, for sure, but once you know that, it is just a matter of being observant.
Many "air-locks" are the result of leaks! So be, well - - observant!

always!

pieterm · 11th October 2018, 06:42

Thanks Kaiser. I think I've to hell and back with airlocks! Beauty of this simple device is leaks can be noted if the pressure drops. In my case, very stable. The matrix worked out to be OK ... maybe the blockage cleared itself? Not sure but all I care is that it works. Again thanks for all your help previously. Really appreciated.

kaiser · 11th October 2018, 15:37

More than welcome, always!

pieterm · 21st October 2018, 21:25

Quote:

Originally Posted by kaiser

More than welcome, always!

Just when I thought all was fixed, proven by warm air in the cabin, I get disappointed ... again.

If anyone can work this one out and offer direction ... please

After some days of what appeared to be a working heater, I firstly noted both pipes into the matrix were tepid. No more heat but at least not icy cold

But, this morning, after a 100km trip in a very cold car I noted that the top pipe was warm to hot to touch and the bottom pipe cold That is completely the opposite to what I would expect as normal. (I should add that I haven't replaced the drivers well trim so I can easily check the matrix ... until I'm confident all is good).

Does this ring any bells with anyone?

Thanking you in advance

T-Cut · 22nd October 2018, 13:42

If the heater was working fine, but progressively lost effectiveness, then the cause is lack of coolant flow through the matrix. Logically, a residual air bubble has circulated, probably into the matrix and become lodged there, breaking the flow. So, either the initial refilling left some air in the system, or coolant has leaked out and naturally replaced by air. The first thing the try is a re-bleed/filling excercise.

You should also check for coolant leakage from the thermostat housing into the V between the heads.

TC

pieterm · 24th October 2018, 01:07

Quote:

Originally Posted by T-Cut

If the heater was working fine, but progressively lost effectiveness, then the cause is lack of coolant flow through the matrix. Logically, a residual air bubble has circulated, probably into the matrix and become lodged there, breaking the flow. So, either the initial refilling left some air in the system, or coolant has leaked out and naturally replaced by air. The first thing the try is a re-bleed/filling excercise.

You should also check for coolant leakage from the thermostat housing into the V between the heads.

TC

Thanks for that, T-Cut. What I have noticed is very peculiar as it varies so much. For example, both pipes might be ice cold or they might be luke warm. Rarely does the bottom pipe become too hot to touch but, when it does, the cabin gets filled with nice warm air!

But sometimes, after a long run, both pipes will become ice cold after being quite warm a few minutes earlier. This morning I disconnected the top pipe at the junction near the battery. The pipes felt empty and, sure enough, no coolant was to be seen! I gently blew air (from mouth not compressor) down the end of the pipe that goes towards the radiator and it was some time before fluid came back through the system and out of the matrix. One big airlock, I'm thinking. Having topped up again, I now note both pipes are luke warm again so am hoping to see improvement as more air is dissipated. It would be nice to have hot air coming through the system

I can't see any leaks anywhere so this whole affair has me beat. I can understand why so many members find it frustrating. I'm at the stage where I would willingly throw money at someone to fix it once and for all. If anyone knows an expert in Melbourne Australia, please let me know. Thanks again, T-Cut ... if the above rings any bells, I'd much appreciate your direction.

T-Cut · 24th October 2018, 17:47

The V6 top-up and bleed procedure is well documented around the forum and is also described in the Haynes manual - an essential buy IMO. That's the first thing to check through. Another approach to difficult air locking is to evacuate the system with a suitable pump. The popular vacuum oil changing pumps are suitable. This HowTo might help if handling vacuum is not your thing: https://the75andztclub.co.uk/forum/s...ad.php?t=41864
TC

pieterm · 24th October 2018, 20:32

Thanks TC. Yes, many many posts on this subject. Maybe too many LOL. Many seem to vary in a small way, or maybe it's how they're being described? I do have a vacuum pump (type that fits to compressor) and the Haynes manual. I noted late yesterday that after a while driving, I felt cold air on my feet ... yep, bottom pipe hot (very), top pipe ice cold. Seems the blockage is back! I'll start over again this weekend - remove matrix and give it a good swirl out etc. I did notice some silvery flecks in the coolant some time back so am wondering if a form of stop-leak may have been used in the past, I'll make sure it gets a good flush out this time

disaacs12 · 5th November 2018, 18:02

Hi, I've had a problem with my V6 75 blowing cold/luke warm. Now i've been a motor mechanic for over 50 years, so I know a bit. I traced the fault on mine to the oil cooler and water pipes going to and coming from the cooler being blocked. I bypassed the cooler and hey presto the heater works perfectly. I think the blockage was causing a back pressure in the return pipe and stopping the flow from the heater. Just to point out that the return pipe from the cooler is teed into the return pipe from the heater. Best of luck.

pieterm · 5th November 2018, 21:58

Interesting point and certainly sounds similar. I completely flushed the system and had nice warm air for a while ... but I have noticed that when the heater goes luke warm. squeezing the hose from the top of the matrix a few times causes everything to heat up again. Also, have noticed sometimes passenger side cooler - not always, just sometimes. Will follow your advise to see if anything is blocking but might have to bite the bullet and get a new matrix ... at least I'll know the matrix is not the problem if I still have the same issues

At least the airconditioning works well ... something more important for this time of year

11th October 2018, 05:05	#11
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	Glad it worked for you. But a fill, with subsequent top ups, will always sort things out. It is a tricky one to fill, for sure, but once you know that, it is just a matter of being observant. Many "air-locks" are the result of leaks! So be, well - - observant! always! __________________ Worth his V8 in gold

11th October 2018, 15:37	#13
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	More than welcome, always! __________________ Worth his V8 in gold

22nd October 2018, 13:42	#15
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	If the heater was working fine, but progressively lost effectiveness, then the cause is lack of coolant flow through the matrix. Logically, a residual air bubble has circulated, probably into the matrix and become lodged there, breaking the flow. So, either the initial refilling left some air in the system, or coolant has leaked out and naturally replaced by air. The first thing the try is a re-bleed/filling excercise. You should also check for coolant leakage from the thermostat housing into the V between the heads. TC Last edited by T-Cut; 22nd October 2018 at 13:45..

24th October 2018, 17:47	#17
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	The V6 top-up and bleed procedure is well documented around the forum and is also described in the Haynes manual - an essential buy IMO. That's the first thing to check through. Another approach to difficult air locking is to evacuate the system with a suitable pump. The popular vacuum oil changing pumps are suitable. This HowTo might help if handling vacuum is not your thing: https://the75andztclub.co.uk/forum/s...ad.php?t=41864 TC Last edited by T-Cut; 24th October 2018 at 17:53..

5th November 2018, 18:02	#19
disaacs12 Newbie Rover 75 Conoisseur Join Date: Mar 2010 Location: Newport Posts: 1 Thanks: 0 Thanked 1 Time in 1 Post	Heater cold Hi, I've had a problem with my V6 75 blowing cold/luke warm. Now i've been a motor mechanic for over 50 years, so I know a bit. I traced the fault on mine to the oil cooler and water pipes going to and coming from the cooler being blocked. I bypassed the cooler and hey presto the heater works perfectly. I think the blockage was causing a back pressure in the return pipe and stopping the flow from the heater. Just to point out that the return pipe from the cooler is teed into the return pipe from the heater. Best of luck.

11th October 2018, 06:42	#12
pieterm Regular poster Rover 75 Connoisseur SE Join Date: Mar 2018 Location: Point Cook, Australia Posts: 83 Thanks: 69 Thanked 8 Times in 6 Posts	Thanks Kaiser. I think I've to hell and back with airlocks! Beauty of this simple device is leaks can be noted if the pressure drops. In my case, very stable. The matrix worked out to be OK ... maybe the blockage cleared itself? Not sure but all I care is that it works. Again thanks for all your help previously. Really appreciated.

24th October 2018, 20:32	#18
pieterm Regular poster Rover 75 Connoisseur SE Join Date: Mar 2018 Location: Point Cook, Australia Posts: 83 Thanks: 69 Thanked 8 Times in 6 Posts	Thanks TC. Yes, many many posts on this subject. Maybe too many LOL. Many seem to vary in a small way, or maybe it's how they're being described? I do have a vacuum pump (type that fits to compressor) and the Haynes manual. I noted late yesterday that after a while driving, I felt cold air on my feet ... yep, bottom pipe hot (very), top pipe ice cold. Seems the blockage is back! I'll start over again this weekend - remove matrix and give it a good swirl out etc. I did notice some silvery flecks in the coolant some time back so am wondering if a form of stop-leak may have been used in the past, I'll make sure it gets a good flush out this time

5th November 2018, 21:58	#20
pieterm Regular poster Rover 75 Connoisseur SE Join Date: Mar 2018 Location: Point Cook, Australia Posts: 83 Thanks: 69 Thanked 8 Times in 6 Posts	Interesting point and certainly sounds similar. I completely flushed the system and had nice warm air for a while ... but I have noticed that when the heater goes luke warm. squeezing the hose from the top of the matrix a few times causes everything to heat up again. Also, have noticed sometimes passenger side cooler - not always, just sometimes. Will follow your advise to see if anything is blocking but might have to bite the bullet and get a new matrix ... at least I'll know the matrix is not the problem if I still have the same issues At least the airconditioning works well ... something more important for this time of year