Continued kv6 coolant issues..

biffa75 · 11th July 2021, 21:22

Hi all,

Back in October/November I replaced the thermostat on our 75 due to the previous thermostat o rings being flattened. The thermostat broke apart upon removal. ( It was the original 18 year old unit).

Ever since then I've experienced the following:

Heat output from passenger side dashboard vents to be slightly lower than that of the driver's side.
:- possibly a partially blocked matrix or flap motor? - need to investigate.

Aircon cold air output from passenger side dashboard vents not being as cold as that of the driver's side
:- possibly related to the above - matrix blockage or flap motor? - need to investigate.

Engine running temperature
Steady a road and motorway driving 50+mph results in the diagnostic display showing the coolant temperature to be around 81-83°c regardless of weather and temperature.
:- referring to shurikens thread with his experiences, it would appear that some thermostats are opening to early at a lower temperature.
:- will have to replace the thermostat at some point after sorting other issues.

Despite using the correct mgr coolant system bleeding method of the cooling system. It appears there is still air in the system or.. air able to enter the cooling system. After a drive and the engine is up to temp.. opening the bonnet with the engine turned off, gurgling can be hard around the radiator area. This can also be heard behind the clock inside the car when raising the revs from idle once warm.

Since changing the thermostat and getting the car back on the road in November, it doesn't appear to have lost any coolant, no apparent or obvious leaks and have covered approx 3.5 to 4k miles.

When the thermostat was changed I changed the following:

Straight and curved pipe and housing and clips.
Expansion cap rated 140.
Used deionised water and iirc red oat anti freeze mixed to approx 33% not the factory stated by mgr.

While the current thermostat doesn't leak or present any real issues as far as I can't tell other than running slightly cooler (unless the temperature switch is under reading at which could lead to overheating without being aware until it's too late).. I'm going to attempt to flush the heater matrix to try and have equal heat and air con cooling from the dashboard vents and also to rule this out as an issue relating to the coolant system causing the issues with bleeding.

I'm also going to take a look at the cambelt area. More specifically the water pump for any signs of weeping again.. to rule out any source of issues.

I'm considering buying a thermostat kit from e car parts based in sandy Bedfordshire.
Has anyone any experience of e car parts?

If anyone has any advice or tips as to anything that may help please do share

Thanks
Rob

Shuriken_57 · 11th July 2021, 22:36

Quote:

Originally Posted by biffa75

Hi all,

Back in October/November I replaced the thermostat on our 75 due to the previous thermostat o rings being flattened. The thermostat broke apart upon removal. ( It was the original 18 year old unit).

Ever since then I've experienced the following:

Heat output from passenger side dashboard vents to be slightly lower than that of the driver's side.
:- possibly a partially blocked matrix or flap motor? - need to investigate.

Aircon cold air output from passenger side dashboard vents not being as cold as that of the driver's side
:- possibly related to the above - matrix blockage or flap motor? - need to investigate.

Engine running temperature
Steady a road and motorway driving 50+mph results in the diagnostic display showing the coolant temperature to be around 81-83°c regardless of weather and temperature.
:- referring to shurikens thread with his experiences, it would appear that some thermostats are opening to early at a lower temperature.
:- will have to replace the thermostat at some point after sorting other issues.

Despite using the correct mgr coolant system bleeding method of the cooling system. It appears there is still air in the system or.. air able to enter the cooling system. After a drive and the engine is up to temp.. opening the bonnet with the engine turned off, gurgling can be hard around the radiator area. This can also be heard behind the clock inside the car when raising the revs from idle once warm.

Since changing the thermostat and getting the car back on the road in November, it doesn't appear to have lost any coolant, no apparent or obvious leaks and have covered approx 3.5 to 4k miles.

When the thermostat was changed I changed the following:

Straight and curved pipe and housing and clips.
Expansion cap rated 140.
Used deionised water and iirc red oat anti freeze mixed to approx 33% not the factory stated by mgr.

While the current thermostat doesn't leak or present any real issues as far as I can't tell other than running slightly cooler (unless the temperature switch is under reading at which could lead to overheating without being aware until it's too late).. I'm going to attempt to flush the heater matrix to try and have equal heat and air con cooling from the dashboard vents and also to rule this out as an issue relating to the coolant system causing the issues with bleeding.

I'm also going to take a look at the cambelt area. More specifically the water pump for any signs of weeping again.. to rule out any source of issues.

I'm considering buying a thermostat kit from e car parts based in sandy Bedfordshire.
Has anyone any experience of e car parts?

If anyone has any advice or tips as to anything that may help please do share

Thanks
Rob

Good evening, I also had the problem with the heater matrix. But after several coolant drains, the problem was solved.
Regarding your thermostat, I have the same problem.
I bought two thermostats, one from DMGRS and another original MG Rover.
My operating temperature is identical to yours.
Are the pieces different from the original? I hope someone will help you. I would follow this post.
goodbye

biffa75 · 12th July 2021, 01:52

Hi shuriken,

I have made threads in the past about this issue with the thermostat and running temperature.
The thermostat I currently have fitted also came from dmgrs. Not sure if it is something dmgrs are aware of or if we both have similar or the same issue with our cars that we aren't aware of not related to the thermostat?

Glad to hear your flushing attempts of the matrix cured your issues. I'm hoping to have a good look at it tomorrow "weather permitting".

The only difference in aware of in regards to the thermostat is the design of the housing itself. Later units came with the three additional supportive legs at the base of the housing.

The original thermostat I took off my car was the original mg rover thermostat which didn't have these supporting legs. Despite the o ring on the original thermostat being flattened and allowing coolant passed to sit in the V of the block.. the engine running temperature was sat steadily at 93°c on the motorway etc.

So.. with that, I'm hoping that if e car parts based in sandy, Bedfordshire, will actually send out a thermostat without the extra supporting legs. Their eBay adverts appear to show the thermostats without the legs. I know this seems like a bad move on my part. However the original mg rover units didn't have these supporting legs. If memory serves correctly I read somewhere it was something that was being planned and developed but wasn't put on to production cars due to the collapse of mg rover..

In all honesty, I've been toying with the idea of just "let it be" but I don't see why I should. I like the car and want it to be right so..

Rob

biffa75 · 13th July 2021, 21:37

So.. today I decided to delve into the 75s coolant related issues.

Removed the upper inlet manifold and had a good look around. No leaks found no other issues apparent.

Dropped the matrix out and gave it a damn good flushing! No more white bits (appeared waxy possible wax from the previous thermostat ?)

Anyway..

Started up and bled using the mgr procedure..

For a few seconds the passenger side is just as first hot as the drivers.. then... It begins to tail off to Luke warm ish on the passenger side. Damn!

Tried the air con.. only to find, the passenger side still doesn't blow the same as the drivers side.

Also checked both of the temperature control flap motors.. didn't need cleaning or greasing. Noted that both the drivers side and passenger's side motors don't move from their lowest position and move until the temperature is set to 21°c. Both sides did exactly the same and moved in exactly the same way so.. my assumption here is.. they both work correctly. No faults shown on the digital display either which I believe if one of the temperature control flap motors was at fault. It would be shown as an error code (can't remember what the code is at time of writing).

So... Next thing is...

What could be the cause of the dashboard vents blowing two different temperatures now?.

Matrix removed and flushed
Temperature control flap motors removed, checked, watched for operation (both operated exactly the same).. so

Is it common for the ducting to fall off or become dislodged? Any other possible causes?

Rob

SD1too · 15th July 2021, 07:40

Quote:

Originally Posted by biffa75

What could be the cause of the dashboard vents blowing two different temperatures now?.
Matrix removed and flushed

Perhaps you need to use a more powerful cleaning agent Rob. Soaking overnight should help and when you refill the coolant, use de-ionised/distilled water.

You also originally asked if anyone has experience of E Car Parts, Sandy, Bedfordshire. I do and I recommend them. They are X-Part agents and I bought a thermostat from them, with additional supporting legs, and it has never leaked. The original type without legs should also be watertight provided that it is supplied in MGR branded packaging and, after fitting, the serrated clips on the straight pipe are moved fully outwards then tightened.

Simon

biffa75 · 15th July 2021, 07:53

Hi Simon hope you are well,

Since the matrix flush, the following day I set about flushing the oil cooler and the pipe work under the radiator. Upon re-bleeding the system
. Heat appeared even from both sides.. fiery hot too. The matrix was completely clear in the end.

In the thread made by shuriken I have posted further updates as to my current findings.

I've since spoken with x-part and they have stated they will be having discussions with the company they have taken up with for the manufacture of the thermostats. As shuriken stated, he replaced his first thermostat with one from e car parts and found it to still give the same issue. Running at 82°c. Having stated all this to x-part they are going to investigate it with the manufacturer.

I've ordered another thermostat from summit garage along with the elbow just in case that breaks and new gaskets etc

When the stat arrives, I'll be testing it before fitting.

Hopefully I won't have any more issues. Only issue I do have is..

With air con on, the driver's side was icy cold and the passenger side still blowing warm or at least cool with Econ setting.

Checked the temperature flap motors and no issues and no fault codes and the operation length appears the same on the passenger's side when compared to the motor on the driver's side. I'm hoping a regas will sort the issue but if you know of any other avenues that may also cause the difference in air con temperature output it would be hugely appreciated.

To note : the air con cold temp on the passenger side remains the same wether is dash vents, floor vents or windscreen position.

Thanks
Rob

SD1too · 15th July 2021, 08:14

Hi Rob,

Thanks for your reply. It's very public spirited of you to take the trouble to alert X-Part to the thermostat problem. I did the same thing concerning the modified "drop links" which are inferior to the original design.

Your curved pipe and thermostat housing won't break so long as you remove the black manifold chamber and the LH bank inlet manifold for access, use lubricant on new 'O' rings and resist being heavy handed!

I'm afraid that I'm as puzzled as you are regarding your air con. I can't see how a re-gas will help.

Looking forward to the result of your bench test of the newly supplied thermostat.

Simon

dave lincs · 15th July 2021, 08:23

Quote:

Originally Posted by biffa75

So.. today I decided to delve into the 75s coolant related issues.

Removed the upper inlet manifold and had a good look around. No leaks found no other issues apparent.

Dropped the matrix out and gave it a damn good flushing! No more white bits (appeared waxy possible wax from the previous thermostat ?)

Anyway..

Started up and bled using the mgr procedure..

For a few seconds the passenger side is just as first hot as the drivers.. then... It begins to tail off to Luke warm ish on the passenger side. Damn!

Tried the air con.. only to find, the passenger side still doesn't blow the same as the drivers side.

Also checked both of the temperature control flap motors.. didn't need cleaning or greasing. Noted that both the drivers side and passenger's side motors don't move from their lowest position and move until the temperature is set to 21°c. Both sides did exactly the same and moved in exactly the same way so.. my assumption here is.. they both work correctly. No faults shown on the digital display either which I believe if one of the temperature control flap motors was at fault. It would be shown as an error code (can't remember what the code is at time of writing).

So... Next thing is...

What could be the cause of the dashboard vents blowing two different temperatures now?.

Matrix removed and flushed
Temperature control flap motors removed, checked, watched for operation (both operated exactly the same).. so

Is it common for the ducting to fall off or become dislodged? Any other possible causes?

Rob

Hi if your heater is cold on the left it will be the matrix is blocked I have done a few like this, if you remove it you can reverse flush it with a hose pipe or if brave a pressure washer that can often clear it

Dave

biffa75 · 15th July 2021, 08:26

As you may recall I myself had issues with the thermostat I received from dmgrs. This appears to have happened to other members of this club too. After reading the issues shuriken has experienced and then another member also having issues with his/her thermostat opening early too, I thought it was time that, at the very least some investigation should be done to the probable cause. I don't believe this is an issue relating to one particular parts stockist/seller as more than one seller has come back having sold a thermostat which reportedly opens at exactly the same point (82°c).

So.. possibly a bad batch or incorrect thermostat ? Who knows, that's for x-part to look into now. Hopefully the stockists/sellers will be able to correct their kv6 thermostats to units that work operate at the correct opening temperature. (Should it be proven to be the issue that is.).

I understand and I will be removing the upper inlet and lower inlet manifold again to have full and proper access to ensure everything clean or as clean as possibly can be to ensure when reassembly is complete I should be free of any leaks or other issues.

My current thermostat despite being faulty hasn't given any issues as far as leaks are concerned in some 3-4k miles.

I'm pretty stumped too in regards to the air con issue... My only logical explination left now is.. air con system needs vacuuming and fresh oil and gas to hopefully bring the condenser etc back up to optimum working condition. Otherwise.. I'm going to be really stumped

I'll reply to this and also shurikens thread with any further information.

11th July 2021, 21:22	#1
biffa75 Trader Mk1 2004 tourer cdti + MK1 2003 Saloon CDT Join Date: Nov 2015 Location: west yorkshire Posts: 495 Thanks: 106 Thanked 91 Times in 57 Posts	Continued kv6 coolant issues.. Hi all, Back in October/November I replaced the thermostat on our 75 due to the previous thermostat o rings being flattened. The thermostat broke apart upon removal. ( It was the original 18 year old unit). Ever since then I've experienced the following: Heat output from passenger side dashboard vents to be slightly lower than that of the driver's side. :- possibly a partially blocked matrix or flap motor? - need to investigate. Aircon cold air output from passenger side dashboard vents not being as cold as that of the driver's side :- possibly related to the above - matrix blockage or flap motor? - need to investigate. Engine running temperature Steady a road and motorway driving 50+mph results in the diagnostic display showing the coolant temperature to be around 81-83°c regardless of weather and temperature. :- referring to shurikens thread with his experiences, it would appear that some thermostats are opening to early at a lower temperature. :- will have to replace the thermostat at some point after sorting other issues. Despite using the correct mgr coolant system bleeding method of the cooling system. It appears there is still air in the system or.. air able to enter the cooling system. After a drive and the engine is up to temp.. opening the bonnet with the engine turned off, gurgling can be hard around the radiator area. This can also be heard behind the clock inside the car when raising the revs from idle once warm. Since changing the thermostat and getting the car back on the road in November, it doesn't appear to have lost any coolant, no apparent or obvious leaks and have covered approx 3.5 to 4k miles. When the thermostat was changed I changed the following: Straight and curved pipe and housing and clips. Expansion cap rated 140. Used deionised water and iirc red oat anti freeze mixed to approx 33% not the factory stated by mgr. While the current thermostat doesn't leak or present any real issues as far as I can't tell other than running slightly cooler (unless the temperature switch is under reading at which could lead to overheating without being aware until it's too late).. I'm going to attempt to flush the heater matrix to try and have equal heat and air con cooling from the dashboard vents and also to rule this out as an issue relating to the coolant system causing the issues with bleeding. I'm also going to take a look at the cambelt area. More specifically the water pump for any signs of weeping again.. to rule out any source of issues. I'm considering buying a thermostat kit from e car parts based in sandy Bedfordshire. Has anyone any experience of e car parts? If anyone has any advice or tips as to anything that may help please do share Thanks Rob

13th July 2021, 21:37	#4
biffa75 Trader Mk1 2004 tourer cdti + MK1 2003 Saloon CDT Join Date: Nov 2015 Location: west yorkshire Posts: 495 Thanks: 106 Thanked 91 Times in 57 Posts	An update So.. today I decided to delve into the 75s coolant related issues. Removed the upper inlet manifold and had a good look around. No leaks found no other issues apparent. Dropped the matrix out and gave it a damn good flushing! No more white bits (appeared waxy possible wax from the previous thermostat ?) Anyway.. Started up and bled using the mgr procedure.. For a few seconds the passenger side is just as first hot as the drivers.. then... It begins to tail off to Luke warm ish on the passenger side. Damn! Tried the air con.. only to find, the passenger side still doesn't blow the same as the drivers side. Also checked both of the temperature control flap motors.. didn't need cleaning or greasing. Noted that both the drivers side and passenger's side motors don't move from their lowest position and move until the temperature is set to 21°c. Both sides did exactly the same and moved in exactly the same way so.. my assumption here is.. they both work correctly. No faults shown on the digital display either which I believe if one of the temperature control flap motors was at fault. It would be shown as an error code (can't remember what the code is at time of writing). So... Next thing is... What could be the cause of the dashboard vents blowing two different temperatures now?. Matrix removed and flushed Temperature control flap motors removed, checked, watched for operation (both operated exactly the same).. so Is it common for the ducting to fall off or become dislodged? Any other possible causes? Rob

15th July 2021, 08:14	#7
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,394 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Hi Rob, Thanks for your reply. It's very public spirited of you to take the trouble to alert X-Part to the thermostat problem. I did the same thing concerning the modified "drop links" which are inferior to the original design. Your curved pipe and thermostat housing won't break so long as you remove the black manifold chamber and the LH bank inlet manifold for access, use lubricant on new 'O' rings and resist being heavy handed! I'm afraid that I'm as puzzled as you are regarding your air con. I can't see how a re-gas will help. Looking forward to the result of your bench test of the newly supplied thermostat. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

12th July 2021, 01:52	#3
biffa75 Trader Mk1 2004 tourer cdti + MK1 2003 Saloon CDT Join Date: Nov 2015 Location: west yorkshire Posts: 495 Thanks: 106 Thanked 91 Times in 57 Posts	Hi shuriken, I have made threads in the past about this issue with the thermostat and running temperature. The thermostat I currently have fitted also came from dmgrs. Not sure if it is something dmgrs are aware of or if we both have similar or the same issue with our cars that we aren't aware of not related to the thermostat? Glad to hear your flushing attempts of the matrix cured your issues. I'm hoping to have a good look at it tomorrow "weather permitting". The only difference in aware of in regards to the thermostat is the design of the housing itself. Later units came with the three additional supportive legs at the base of the housing. The original thermostat I took off my car was the original mg rover thermostat which didn't have these supporting legs. Despite the o ring on the original thermostat being flattened and allowing coolant passed to sit in the V of the block.. the engine running temperature was sat steadily at 93°c on the motorway etc. So.. with that, I'm hoping that if e car parts based in sandy, Bedfordshire, will actually send out a thermostat without the extra supporting legs. Their eBay adverts appear to show the thermostats without the legs. I know this seems like a bad move on my part. However the original mg rover units didn't have these supporting legs. If memory serves correctly I read somewhere it was something that was being planned and developed but wasn't put on to production cars due to the collapse of mg rover.. In all honesty, I've been toying with the idea of just "let it be" but I don't see why I should. I like the car and want it to be right so.. Rob

15th July 2021, 07:53	#6
biffa75 Trader Mk1 2004 tourer cdti + MK1 2003 Saloon CDT Join Date: Nov 2015 Location: west yorkshire Posts: 495 Thanks: 106 Thanked 91 Times in 57 Posts	Hi Simon hope you are well, Since the matrix flush, the following day I set about flushing the oil cooler and the pipe work under the radiator. Upon re-bleeding the system . Heat appeared even from both sides.. fiery hot too. The matrix was completely clear in the end. In the thread made by shuriken I have posted further updates as to my current findings. I've since spoken with x-part and they have stated they will be having discussions with the company they have taken up with for the manufacture of the thermostats. As shuriken stated, he replaced his first thermostat with one from e car parts and found it to still give the same issue. Running at 82°c. Having stated all this to x-part they are going to investigate it with the manufacturer. I've ordered another thermostat from summit garage along with the elbow just in case that breaks and new gaskets etc When the stat arrives, I'll be testing it before fitting. Hopefully I won't have any more issues. Only issue I do have is.. With air con on, the driver's side was icy cold and the passenger side still blowing warm or at least cool with Econ setting. Checked the temperature flap motors and no issues and no fault codes and the operation length appears the same on the passenger's side when compared to the motor on the driver's side. I'm hoping a regas will sort the issue but if you know of any other avenues that may also cause the difference in air con temperature output it would be hugely appreciated. To note : the air con cold temp on the passenger side remains the same wether is dash vents, floor vents or windscreen position. Thanks Rob

15th July 2021, 08:26	#9
biffa75 Trader Mk1 2004 tourer cdti + MK1 2003 Saloon CDT Join Date: Nov 2015 Location: west yorkshire Posts: 495 Thanks: 106 Thanked 91 Times in 57 Posts	As you may recall I myself had issues with the thermostat I received from dmgrs. This appears to have happened to other members of this club too. After reading the issues shuriken has experienced and then another member also having issues with his/her thermostat opening early too, I thought it was time that, at the very least some investigation should be done to the probable cause. I don't believe this is an issue relating to one particular parts stockist/seller as more than one seller has come back having sold a thermostat which reportedly opens at exactly the same point (82°c). So.. possibly a bad batch or incorrect thermostat ? Who knows, that's for x-part to look into now. Hopefully the stockists/sellers will be able to correct their kv6 thermostats to units that work operate at the correct opening temperature. (Should it be proven to be the issue that is.). I understand and I will be removing the upper inlet and lower inlet manifold again to have full and proper access to ensure everything clean or as clean as possibly can be to ensure when reassembly is complete I should be free of any leaks or other issues. My current thermostat despite being faulty hasn't given any issues as far as leaks are concerned in some 3-4k miles. I'm pretty stumped too in regards to the air con issue... My only logical explination left now is.. air con system needs vacuuming and fresh oil and gas to hopefully bring the condenser etc back up to optimum working condition. Otherwise.. I'm going to be really stumped I'll reply to this and also shurikens thread with any further information.