V6 Thermostat

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Tempus Fugit

Tempus Fugit

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Had the thermostat replaced just over 12 months ago, it now seems it's failed again and stuck closed, top hose solid, bottom very cold and showing around 106-108 on the app - not good I suspect? Is it common for the these to fail in such a short period of time? Done around 7k miles since it was replaced. Will I need to replace the connecting pipes (they were done at the time) or will a new 'stat be all that is required? In addition which one to go for, Rimmers have them at £65, LR Direct have them at £18 and at Paddock Spares they are £14. I'd rather replace it with something that is going to last and work this time, but do I really need to spend £65?

Ta.
 
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When I was running V6s I'd change the thermostat every coolant change (5 yearly)
It's uncommon for them to fail, especially when you consider how hot the KV6 runs. 106°C isn't uncommon tbh. My V6 Freelander ran at 110+ when towing a heavily loaded trailer up a long hill. The gauge won't even move into the red sector unless the engine temperature exceeds 115° C.
 
Thanks Nodge

It hits 108 at a stand still though (I've seen 110 briefly), usually when I park up. It then sits at around 106 with fans going like the clappers and doesn't drop, although I think there may be a problem with the sensor as the fans don't come on until 105? When sitting on the A14 at a steady 70 it shows around 102, this cant be right surely? Pretty certain that the V6s in the ZT/75 run at a lot lower temperature <100?
 
The KV6 engine generally shows about 100°C under a light load.
The fans are under ECU control and don't start running until the engine exceeds 105°C. That this point the fans run at the slow speed. If everything is working correctly and the ambient temperature is under about 20°C, the fans cycle, slow, stop, slow, stop and so on. When the engine starts to work harder, the temperature will climb but the fans should always cool it down again. If the fans aren't making headway then you need to check the cooling system carefully for blocked rad cores and general degradation.
 
My MGZT V6 2.5 190 runs at 91-92 at normal running 50-70 mph or knocking about, if stationary when it doe's reach 100c the slow fan kicks in and bring temp down to 95c right away, once on the move it will revert to the 91-92c, my thermostat failed after about 15 months O-rings flattened which resulted in a leak into the V of the engine, I changed the thermostat with a different one which as three lug that seat the thermostat level and flat onto the head, this I hope is and as so far kept the thermostat unit from and movement thus causing the failed O-rings.

link as to where I purchased the one I have fitted now, not sure if it will fit the Freelander 1 and the pipes may be different.
http://www.ebay.co.uk/itm/141114952862?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

Replaced by keyhole method
http://www.75ztcommunity.co.uk/thermostat-replaced-key-hole-v6-190-t7976.html
 
The V6 engine fitted into Rovers does run cooler than when it is in the Freelander. My ZS180s typically ran at around 89-91°C I'm not sure why LR made it run so hot. I suspect it was to help emissions, but that's just a guess. I expect the auto box pushes the running temperature up too. Maybe the high running temperature is to help with box shift quality?
The Rover thermostat does fit in the Freelander engine but the piping needs to be modified to suit.
 
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Sorry missed the replies. Basically I bled it following the heat exchanger leak and replacement. Fans come on at 105-106, briefly hits 107 then drops to below 105. When on the move it sits at about 99-101, which is a lot less than before.

Not sure of the type of 'stat.

Thanks for the replies and help.
 
Tempus Fugit said:
Sorry missed the replies. Basically I bled it following the heat exchanger leak and replacement. Fans come on at 105-106, briefly hits 107 then drops to below 105. When on the move it sits at about 99-101, which is a lot less than before.

Not sure of the type of 'stat.

Thanks for the replies and help.
Click to expand...
That's working as it should;)
 
It's extremely common they fail in my experience. I've yet to own a kv6 it hasn't happened in, and I've yet to know someone with a kv6 is hasn't occurred in also.

You may try mat at discount mg rover parts, he does a smashing deal on them currently and warrentied parts unlike many other places can get you correct spec on rings etc with it.
 
There's a guy on the 75/ZT and Mgrover.org I think his name is Kaiser takes orders for metal thermostats for the KV6 engines. To date not one failure.
 
Paulontour said:
There's a guy on the 75/ZT and Mgrover.org I think his name is Kaiser takes orders for metal thermostats for the KV6 engines. To date not one failure.
Click to expand...
Kaiser's metal thermostat is copied from a Rover KV6 thermostat. These are different to the thermostat fitted to the KV6 Freelander. The Freelander uses quick release connections and the bypass pipe is above the rad return pipe. The Rover stat has the bypass below the rad return and the connections are standard push on, hose clip type.
Freelander stat
Screenshot_20160516-105449.png

Rover stat
Screenshot_20160516-110053.png
 
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I have used the Rover thermostat in the Freelander but it's not ideal tbh. It's better to get the correct type. There are a few differences between the Freelander KV6 and the Rover version, mostly to do with ancillaries and mounts. The exhaust manifolds and system is different too.
 
I use the Kaiser alloy metal thermostat in my wife's Freelander here in Canada. As Nodge68 stated, the quick connect hose connections had to be removed. I like not having to worry about yet more plastic breaking.
 
zefrench said:
I use the Kaiser alloy metal thermostat in my wife's Freelander here in Canada. As Nodge68 stated, the quick connect hose connections had to be removed. I like not having to worry about yet more plastic breaking.
Click to expand...
To be honest. If I lived as far away from cheap thermostats as you, the Kaiser thermostat would be my preference too ;)
 
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