Anybody know how the Sapph 4x4 Cooling system works...???
21-03-2005, 02:52 PM
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Anybody know how the Sapph 4x4 Cooling system works...???
If so can you please explain it to me....
The thermostat housing is connected to the bottom of the radiator and the water pump to the top....right???
So the water flows out of the head HOT and into the top of the rad top hose...
cools as it passes through it, then returns from the bottom of the rad to the thermostat housing.....
Im guessing ive got this wrong....
so where does the thermostat come into play?
where does it flow to and from etc....
My engine still gets hot...
my top rad feed is HOT.....my Bottom hose is VERY COLD so im confused as to why the cold water isn't getting to the engine......
The thermostat housing is connected to the bottom of the radiator and the water pump to the top....right???
So the water flows out of the head HOT and into the top of the rad top hose...
cools as it passes through it, then returns from the bottom of the rad to the thermostat housing.....
Im guessing ive got this wrong....
so where does the thermostat come into play?
where does it flow to and from etc....
My engine still gets hot...
my top rad feed is HOT.....my Bottom hose is VERY COLD so im confused as to why the cold water isn't getting to the engine......
21-03-2005, 04:08 PM
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take your thermostat out put it in kettle with the lid off boil the water if the thermo does nothing buy a new one,flush the entire water system with rad flush,put redline wetter water £16.50 from burtonpower. if still gets to hot it's probaly water pump
21-03-2005, 04:10 PM
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youyr correct on flow 
the thermostat holds the water back from returning, then once hot opens up and allows water in head,
thats how i thought anyhow.
but i have an issue, same as you infact
the thermostat holds the water back from returning, then once hot opens up and allows water in head,
thats how i thought anyhow.
but i have an issue, same as you infact
21-03-2005, 05:02 PM
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Thanks for the replies....
Therefore...as long as my return water is cooler than the stat the stat wont open....
That must be whats happening.
so the water is being kept in the head and not allowed to circulate through the rad by the stat staying closed....
Strange though as the water temp from the gauge sensor (on the head) shows the water temp rising above that which the stat opens....But why???
Any more thoughts....
By the way its a new Stat.
Perhaps drilling a small hole in the stat to allow some water to circulate would help...
Therefore...as long as my return water is cooler than the stat the stat wont open....
That must be whats happening.
so the water is being kept in the head and not allowed to circulate through the rad by the stat staying closed....
Strange though as the water temp from the gauge sensor (on the head) shows the water temp rising above that which the stat opens....But why???
Any more thoughts....
By the way its a new Stat.
Perhaps drilling a small hole in the stat to allow some water to circulate would help...
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21-03-2005, 06:16 PM
#10
Various possibilities, but the system is so simple it cannot be hard to trace.
1) Engine heats up water.
2) At 88degrees it starts to flow into radiator
3) The radiator cools it
4) If temperatire of water is much less than 88 degrees, stat closes slightly.
5) Stat "regulates" the flow so teh water hovers around 88
6) If above fails... fans come on. Only reason can be no cooling flow of air through rad.
If the above scenario doesnt work as described you have no flow of water through the rad or no flow of air.....
No water: =
Blocked rad
Dead water pump
Air lock.
No water pressure (Header tank cap or water leak)
Other obstruction to flow
Enjoy.
1) Engine heats up water.
2) At 88degrees it starts to flow into radiator
3) The radiator cools it
4) If temperatire of water is much less than 88 degrees, stat closes slightly.
5) Stat "regulates" the flow so teh water hovers around 88
6) If above fails... fans come on. Only reason can be no cooling flow of air through rad.
If the above scenario doesnt work as described you have no flow of water through the rad or no flow of air.....
No water: =
Blocked rad
Dead water pump
Air lock.
No water pressure (Header tank cap or water leak)
Other obstruction to flow
Enjoy.
21-03-2005, 06:19 PM
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Thinking about it again....
The water in the head and block are cirulated through to the stat housing and out to the top rad hose...
through the rad and out the bottom rad hose and back up to the thermostat housing to the Thermostat.
Once the water temp in the system reaches stat opening temp, stat opens and the cooled water then circulates through the block and head again.....
So as my water return from the bottom of the rad is stone cold the stat wont open right???
im confused Stu, as i cant see why flow would affect the temp of the water at the stat....what am i missing???
The water in the head and block are cirulated through to the stat housing and out to the top rad hose...
through the rad and out the bottom rad hose and back up to the thermostat housing to the Thermostat.
Once the water temp in the system reaches stat opening temp, stat opens and the cooled water then circulates through the block and head again.....
So as my water return from the bottom of the rad is stone cold the stat wont open right???
im confused Stu, as i cant see why flow would affect the temp of the water at the stat....what am i missing???
21-03-2005, 07:21 PM
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the 4x4 system is slightly unusual, in as much as it has a 2-valve thermostat in a more complex 2-chamber stat housing - if you compare to a 'normal (eg 2wd ) one it is longer with a small disc at the back as well as the main disc at the front.
When cold, the 'closed' main disc shuts off the return from the bottom of the rad, and the 'open' rear disc allows water to circulate from the head outlet back into the pump and to the block.
When the coolant is hot enough to open the stat (the stat body sits in the bypass circulating flow at this stage), then the small rear disc closes off the bypass port in the stat housing at the same time as opening the main disc, thus diverting the main flow round the rad rather than 'shortcutting' through the bypass in the stat housing.
Are you sure you have a proper 4x4 thermostat fitted, and not a 2wd one? It's feasible that with a 2wd stat, which only has the main disc, that because the bypass channel in the stat housing doesn't get closed off, that even when the stat is open, the flow could still be passing round the bypass thus shortcutting the route round the rad..
When cold, the 'closed' main disc shuts off the return from the bottom of the rad, and the 'open' rear disc allows water to circulate from the head outlet back into the pump and to the block.
When the coolant is hot enough to open the stat (the stat body sits in the bypass circulating flow at this stage), then the small rear disc closes off the bypass port in the stat housing at the same time as opening the main disc, thus diverting the main flow round the rad rather than 'shortcutting' through the bypass in the stat housing.
Are you sure you have a proper 4x4 thermostat fitted, and not a 2wd one? It's feasible that with a 2wd stat, which only has the main disc, that because the bypass channel in the stat housing doesn't get closed off, that even when the stat is open, the flow could still be passing round the bypass thus shortcutting the route round the rad..
21-03-2005, 07:41 PM
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Thanks for the reply.
I recently bought the Stat, and as well as being sure its is a 4wd one, i seem to remember they are different in size also, so cannot be interchanged....
Strange thing is, the last time i used it worked fine, exactly as it should with the fan shutting off after having cooled back down after only 1 minute...
then the other day i noticed it creep up higher than normal and then the fan stayed on....
Any thoughts based on this as i dont really want to shell out for a new pump unnecessarily.
Is the 4wd setup better than the 2wd one?
I recently bought the Stat, and as well as being sure its is a 4wd one, i seem to remember they are different in size also, so cannot be interchanged....
Strange thing is, the last time i used it worked fine, exactly as it should with the fan shutting off after having cooled back down after only 1 minute...
then the other day i noticed it creep up higher than normal and then the fan stayed on....
Any thoughts based on this as i dont really want to shell out for a new pump unnecessarily.
Is the 4wd setup better than the 2wd one?
21-03-2005, 07:58 PM
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well i have exactly the same problem as you 
i have a rad (with slight leak) that i will be putting on this week (maybe tomorrow) and will see if it fix's the problem
i have a rad (with slight leak) that i will be putting on this week (maybe tomorrow) and will see if it fix's the problem
21-03-2005, 08:04 PM
#19
Originally Posted by Spiky
well i have exactly the same problem as you
i have a rad (with slight leak) that i will be putting on this week (maybe tomorrow) and will see if it fix's the problem
i have a rad (with slight leak) that i will be putting on this week (maybe tomorrow) and will see if it fix's the problem
needs the pressure to keep the temp stable
22-03-2005, 08:52 AM
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yep....aluminium 4 core, only done 800 miles now.....
and recently flushed and filled system with new antifreeze....
There were no bits in the water drained...
and recently flushed and filled system with new antifreeze....
There were no bits in the water drained...
22-03-2005, 09:18 AM
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Re: Anybody know how the Sapph 4x4 Cooling system works...??
Originally Posted by CosRush
my top rad feed is HOT.....my Bottom hose is VERY COLD so im confused as to why the cold water isn't getting to the engine......
How much of the rad is hot?
it really sounds to me like your thermostat isn't opening, so the bypass channel stays open circulating coolant round the head/block but blanking off the rad return flow. The top hose will get hot from conduction, but from what you've said, I'd guess the rad is probably cold due to no flow?
22-03-2005, 09:21 AM
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Re: Anybody know how the Sapph 4x4 Cooling system works...??
Originally Posted by richm
Originally Posted by CosRush
my top rad feed is HOT.....my Bottom hose is VERY COLD so im confused as to why the cold water isn't getting to the engine......
How much of the rad is hot?
it really sounds to me like your thermostat isn't opening, so the bypass channel stays open circulating coolant round the head/block but blanking off the rad return flow. The top hose will get hot from conduction, but from what you've said, I'd guess the rad is probably cold due to no flow?
yet wtill have the same issue as CosRush
22-03-2005, 09:32 AM
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Re: Anybody know how the Sapph 4x4 Cooling system works...??
Rich asked:
So is the rad hot? or just the hose?
How much of the rad is hot?
So is the rad hot? or just the hose?
How much of the rad is hot?
22-03-2005, 09:33 AM
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Re: Anybody know how the Sapph 4x4 Cooling system works...??
Originally Posted by CosRush
Rich asked:
So is the rad hot? or just the hose?
How much of the rad is hot?
So is the rad hot? or just the hose?
How much of the rad is hot?
in that case you have just got hot water convecting through the right hand hose down into rad with no circulation
22-03-2005, 09:45 AM
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Sounds like the blockage might be round the thermostat housing.
Did you clean off all the sealant and other crap that you usually find in there?
Not 100% about 4x4 thermostats, as I've never changed a 4x4 one personally, but you can't put them in the wrong way round can ya?
Did you clean off all the sealant and other crap that you usually find in there?
Not 100% about 4x4 thermostats, as I've never changed a 4x4 one personally, but you can't put them in the wrong way round can ya?
22-03-2005, 09:51 AM
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Yes it was all fully clean, and from what i remember No you cant get them the wrong way around as the longer part wouldn't fit under the thermostat housing...
22-03-2005, 10:06 AM
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Re: Anybody know how the Sapph 4x4 Cooling system works...??
Originally Posted by Spiky
Originally Posted by richm
Originally Posted by CosRush
my top rad feed is HOT.....my Bottom hose is VERY COLD so im confused as to why the cold water isn't getting to the engine......
How much of the rad is hot?
it really sounds to me like your thermostat isn't opening, so the bypass channel stays open circulating coolant round the head/block but blanking off the rad return flow. The top hose will get hot from conduction, but from what you've said, I'd guess the rad is probably cold due to no flow?
yet wtill have the same issue as CosRush
22-03-2005, 10:11 AM
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Re: Anybody know how the Sapph 4x4 Cooling system works...??
Originally Posted by richm
Originally Posted by CosRush
my top rad feed is HOT.....my Bottom hose is VERY COLD so im confused as to why the cold water isn't getting to the engine......
How much of the rad is hot?
it really sounds to me like your thermostat isn't opening, so the bypass channel stays open circulating coolant round the head/block but blanking off the rad return flow. The top hose will get hot from conduction, but from what you've said, I'd guess the rad is probably cold due to no flow?
Regards
Ian
22-03-2005, 10:12 AM
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richm,
tis really annoying, my next option is to blast water from pipe on inlet side to see if pipe's are ok and flows through the oil cooler ok
else if all fails, one of 2 things will happem
1 run no thermostat
2 run 2wd setup
tis really annoying, my next option is to blast water from pipe on inlet side to see if pipe's are ok and flows through the oil cooler ok
else if all fails, one of 2 things will happem
1 run no thermostat
2 run 2wd setup
22-03-2005, 10:13 AM
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Re: Anybody know how the Sapph 4x4 Cooling system works...??
Originally Posted by sibster
Originally Posted by richm
Originally Posted by CosRush
my top rad feed is HOT.....my Bottom hose is VERY COLD so im confused as to why the cold water isn't getting to the engine......
How much of the rad is hot?
it really sounds to me like your thermostat isn't opening, so the bypass channel stays open circulating coolant round the head/block but blanking off the rad return flow. The top hose will get hot from conduction, but from what you've said, I'd guess the rad is probably cold due to no flow?
Regards
Ian
22-03-2005, 10:14 AM
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Originally Posted by CosRush
yes hoses are new...in fact its all new except the actual Thermostat housing and the water pump.....
