Kv6 new thermostat leaks? - Page 5

Shuriken_57 · 31st May 2021, 09:36

The Viton seals of my cap on the expansion tank are flattened . I will change these.

Arctic · 31st May 2021, 10:51

Quote:

Originally Posted by Shuriken_57

The Viton seals of my cap on the expansion tank are flattened . I will change these.

I doubt the ones on the cap are Viton, they should look like this below.

1

There is one small o-ring and one large one.

2

3

4

At our Nano meets these are changed out FOC

5

Shuriken_57 · 11th June 2021, 16:54

Hello, I used mg rover filling method for coolant. No change. The engine takes a long time to heat and to reach just 80 82 ( it is very hot here in France).
I realized that the temperature oscillates: sometimes it displays 85 degrees then a second after 78 and then goes up . I had changed my sensor by a dmgrs, I did not keep my original bmw sensor.

When I disassembled my thermostat , some coolant has flowed on the sensor and its wiring. Do you think the sensor is defective?
The coolant level is stable.
Thanks you.

SD1too · 12th June 2021, 10:30

Quote:

Originally Posted by Shuriken_57

The Viton seals of my cap on the expansion tank are flattened . I will change these.

Have you done this yet Brahim?

Quote:

Originally Posted by Shuriken_57

I think I have a leak even though I have no trace under the car or in the v . I’m afraid it’s the water pump ( it was replaced 6 months ago but I had seen traces of dried coolant under the place where the water pump is mounted).
In fact, I smell coolant when I get out of the vehicle (hot engine).

You need to establish whether or not your water pump is leaking. You will see low temperature indications which vary with road speed if the cooling system is not sealed. Those are the symptoms you've reported (see post no. 16). You should not have changed the temperature sender without firm evidence that it was faulty and you should have kept the original.

Simon

murphyv310 · 12th June 2021, 11:19

Hi.
I'm still surprised that there are threads about this issue. I discussed this many times when I owned a KV6 a few years ago. I did my thermostat by the keyhole method. Its imperative to clean off the crud round the hole for the thermostat, it doesn't need to be shiny but there has to be a clean surface and bore with no pitting or corrosion and a nice grey surface. The Viton O rings must be properly lubricated with only Molycote 111, I keep banging on about this and will till the cows come home. Its not cheap but a tube will last for years. Do this once and then forget it. I also found some themostats are copies even those from reputable sources so beware, from memory it's quite easy to see inside and compare the difference between the original and the copy, all the ones that give cooler running are lower opening and not to Rover spec...... So beware.
The reason the temperature goes up and down is nothing at all to do with the odd drip when the engine cools its the poor quality themostats pulsing open and closing as their thermal range is less due to design.
So get your Molycote 111, new O rings and grease the rings so you'll not get leaks there any more unless the bore and facing of the hole is in a bad way.

PS use Molycote 111 on all your O rings in the cooling system, on the cap etc that is what it's designed for.

https://www.silmid.com/silicones/sil...ze-and-colour/

Shuriken_57 · 7th July 2021, 01:13

Hello, after having settled my tank problem, I now take care of the temperature of the engine because my fuel consumption is high.
The thermostat is new(original part changed twice) and no longer leaks.
I also changed the temperature sensor and the expansion cap.
According to your advice, it could be the water pump (replaced with the cam belts 8 months ago).
Do you think I need a new water pump? The level in the expansion tank is stable but the temperature remains stable at about 82° and rises to 100 in town.
Thank you

kaiser · 7th July 2021, 03:32

Quote:

Originally Posted by Shuriken_57

Hello, after having settled my tank problem, I now take care of the temperature of the engine because my fuel consumption is high.
The thermostat is new(original part changed twice) and no longer leaks.
I also changed the temperature sensor and the expansion cap.
According to your advice, it could be the water pump (replaced with the cam belts 8 months ago).
Do you think I need a new water pump? The level in the expansion tank is stable but the temperature remains stable at about 82° and rises to 100 in town.
Thank you

What is the problem? These cars do use petrol, so what is high?
What has the water pump got to do with it?
The temperatures are fine, it looks to me.

SD1too · 7th July 2021, 07:14

Quote:

Originally Posted by Shuriken_57

Do you think I need a new water pump?

No!

Quote:

Originally Posted by Shuriken_57

... the temperature remains stable at about 82° and rises to 100 in town.

That's too low and will cause increased fuel consumption. The only component that can be responsible for this is the thermostat. Your running temperature should be more like 92°. Either the thermostat is opening early or it's a version for hot climates or it's not a genuine MGR product.

Simon

MGtom91 · 7th July 2021, 12:53

I too have recently fitted a new thermostat and temp sensor supplied by DMGRS and am seeing the same lower running temps using the ipk on my KV6. Maximum temp when car is moving is 78 to 80° regardless of motorway or city driving and I the car will not get any hotter even if giving it 'the beans' Bottom rad hose starts to get warm around 75° and is too hot to hold at 78°. I contacted them with my concern that the car is running on the low side and they assured me that these kits come with 82° stats fitted not 88° as was fitted at factory. They said as long as the car sits in the 'normal' calibrated temperature range of 75 to 115° then not to worry. If the car struggles to maintain the minimum 75° during winter, they will replace the kit FOC. Who knows ??

Shuriken_57 · 7th July 2021, 13:21

Quote:

Originally Posted by SD1too

No!

That's too low and will cause increased fuel consumption. The only component that can be responsible for this is the thermostat. Your running temperature should be more like 92°. Either the thermostat is opening early or it's a version for hot climates or it's not a genuine MGR product.

Simon

Hello Simon, I bought an original mg rover thermostat kit (the one you recommended earlier in this forum) and another thermostat from DMGRS, but the operating temperatures are identical.
I had read that this could be from an unsealed system.
I would be surprised if I bought two defective thermostats. Perhaps they are no longer calibrated to open at 88°.

31st May 2021, 09:36	#41
Shuriken_57 Avid contributor Rover 75 Join Date: Jan 2019 Location: Freyming-Merlebach Posts: 212 Thanks: 104 Thanked 21 Times in 12 Posts	The Viton seals of my cap on the expansion tank are flattened . I will change these. Last edited by Shuriken_57; 31st May 2021 at 09:38..

11th June 2021, 16:54	#43
Shuriken_57 Avid contributor Rover 75 Join Date: Jan 2019 Location: Freyming-Merlebach Posts: 212 Thanks: 104 Thanked 21 Times in 12 Posts	Hello, I used mg rover filling method for coolant. No change. The engine takes a long time to heat and to reach just 80 82 ( it is very hot here in France). I realized that the temperature oscillates: sometimes it displays 85 degrees then a second after 78 and then goes up . I had changed my sensor by a dmgrs, I did not keep my original bmw sensor. When I disassembled my thermostat , some coolant has flowed on the sensor and its wiring. Do you think the sensor is defective? The coolant level is stable. Thanks you. Last edited by Shuriken_57; 11th June 2021 at 17:03..

12th June 2021, 11:19	#45
murphyv310 This is my second home Hyundai i10 998cc Join Date: Mar 2012 Location: Kilmarnock Posts: 6,602 Thanks: 2,088 Thanked 2,298 Times in 1,349 Posts	Hi. I'm still surprised that there are threads about this issue. I discussed this many times when I owned a KV6 a few years ago. I did my thermostat by the keyhole method. Its imperative to clean off the crud round the hole for the thermostat, it doesn't need to be shiny but there has to be a clean surface and bore with no pitting or corrosion and a nice grey surface. The Viton O rings must be properly lubricated with only Molycote 111, I keep banging on about this and will till the cows come home. Its not cheap but a tube will last for years. Do this once and then forget it. I also found some themostats are copies even those from reputable sources so beware, from memory it's quite easy to see inside and compare the difference between the original and the copy, all the ones that give cooler running are lower opening and not to Rover spec...... So beware. The reason the temperature goes up and down is nothing at all to do with the odd drip when the engine cools its the poor quality themostats pulsing open and closing as their thermal range is less due to design. So get your Molycote 111, new O rings and grease the rings so you'll not get leaks there any more unless the bore and facing of the hole is in a bad way. PS use Molycote 111 on all your O rings in the cooling system, on the cap etc that is what it's designed for. https://www.silmid.com/silicones/sil...ze-and-colour/ __________________ Cheers from Trevor MM0KJJ Last edited by murphyv310; 12th June 2021 at 11:23..

7th July 2021, 01:13	#46
Shuriken_57 Avid contributor Rover 75 Join Date: Jan 2019 Location: Freyming-Merlebach Posts: 212 Thanks: 104 Thanked 21 Times in 12 Posts	Hello, after having settled my tank problem, I now take care of the temperature of the engine because my fuel consumption is high. The thermostat is new(original part changed twice) and no longer leaks. I also changed the temperature sensor and the expansion cap. According to your advice, it could be the water pump (replaced with the cam belts 8 months ago). Do you think I need a new water pump? The level in the expansion tank is stable but the temperature remains stable at about 82° and rises to 100 in town. Thank you

7th July 2021, 12:53	#49
MGtom91 Regular poster MG ZT KV6 (160) Join Date: Feb 2018 Location: Solihull Posts: 36 Thanks: 0 Thanked 6 Times in 6 Posts	I too have recently fitted a new thermostat and temp sensor supplied by DMGRS and am seeing the same lower running temps using the ipk on my KV6. Maximum temp when car is moving is 78 to 80° regardless of motorway or city driving and I the car will not get any hotter even if giving it 'the beans' Bottom rad hose starts to get warm around 75° and is too hot to hold at 78°. I contacted them with my concern that the car is running on the low side and they assured me that these kits come with 82° stats fitted not 88° as was fitted at factory. They said as long as the car sits in the 'normal' calibrated temperature range of 75 to 115° then not to worry. If the car struggles to maintain the minimum 75° during winter, they will replace the kit FOC. Who knows ??