|
||
|
28th September 2010, 12:28 | #61 |
This is my second home
Rover75 and Mreg Corsa. Join Date: Nov 2006
Location: Sumweer onat mote o'dust (Sagin)
Posts: 21,754
Thanks: 341
Thanked 3,660 Times in 2,924 Posts
|
There's no fail safe or anything slightly sophisticated about these stats. They have a simple sealed wax capsule containing a piston. The wax melts, expands and pushes the piston out. The valve is attached to the piston. When things cool down, the return spring ensures proper return and closure of the valve. How this device can pass coolant when below the wax setting I don't know.
What's needed is someone to check a 'failed' stat in water to see what happens to it. Does it open at too low a temperature? If so, my understanding of paraffin waxes is incomplete. TC |
28th September 2010, 12:38 | #62 |
Posted a thing or two
Rover 75 Tourer Join Date: Nov 2006
Location: Malpas
Posts: 1,526
Thanks: 34
Thanked 118 Times in 89 Posts
|
"thermostat was bejiggered, and had to be replaced (easy jobs on those cars). It ALWAYS stuck open . My experience anyway. Are modern stats made different ?"
OH now then on second (and many more !) thoughts, the stat always APPEARED to be open . That was before this long discussion. Maybe the stat actually opened at a very much lower temperature than it should, due to loss of wax/water ingress due to overheating. I cant work out the results of this though , only observe that the stat didnt work properly. |
28th September 2010, 16:59 | #63 | |
This is my second home
75 Contemporary SE Mk II 2004 Man. Sal. CDTi 135ps, FBH on red diesel, WinCE6 DD Join Date: May 2010
Location: Leeds
Posts: 17,273
Thanks: 2,160
Thanked 2,061 Times in 1,586 Posts
|
Quote:
|
|
28th September 2010, 17:15 | #64 |
This is my second home
ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007
Location: Conwy NORTH WALES
Posts: 11,094
Thanks: 512
Thanked 1,116 Times in 763 Posts
|
I will test a couple of duff stats in hot water............ when I get time!!
I've always assumed it's simply a case of the spring weakening with age. Fitting another tomorrow & another on Thurs so another full day together with posting lots of parcels.
__________________
[SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block |
29th September 2010, 09:39 | #65 |
Gets stuck in
Rover 75 Connoisseur SE CDT Tourer Join Date: Sep 2009
Location: Herne Bay
Posts: 654
Thanks: 1
Thanked 4 Times in 4 Posts
|
Jules,
That sounds great. It will be very interesting to really know what is happening to the stats. So I assume that you will be testing some faulty stats with a new one as comparison. Will there be a way of testing the spring tension? Matt |
29th September 2010, 16:34 | #66 |
Passed Away
Rover 75 CDT 03 auto Conn. SE Join Date: May 2009
Location: London
Posts: 2,885
Thanks: 104
Thanked 254 Times in 204 Posts
|
Stats
Matt, I have tested my brand new,unfitted, stat three times and it opens at an indicated 91 C. increasing the return spring pressure made no difference as TC indicated. JULES is the key to more knowledge on this problem as he is going to check the opening temps on failed stats. Since
he has never found one stuck open or seized up then, logically, the only problem must be that the stat is opening at a lower temperature? With regard to blanking off the radiator, it is not as simple as on most cars because the intercooler and the air con matrix,and the 2 speed fan resistor, should not be blanked off so has anyone given thought as to the best way to do this? Last edited by wuzerk; 29th September 2010 at 16:38.. |
29th September 2010, 20:59 | #67 | |
This is my second home
Rover75 and Mreg Corsa. Join Date: Nov 2006
Location: Sumweer onat mote o'dust (Sagin)
Posts: 21,754
Thanks: 341
Thanked 3,660 Times in 2,924 Posts
|
Quote:
TC |
|
29th September 2010, 21:03 | #68 |
This is my second home
75 Contemporary SE Mk II 2004 Man. Sal. CDTi 135ps, FBH on red diesel, WinCE6 DD Join Date: May 2010
Location: Leeds
Posts: 17,273
Thanks: 2,160
Thanked 2,061 Times in 1,586 Posts
|
Of course the size of the orifice would need to vary, to take account of the waste energy needing to be disposed of - perhaps you could call it a thermostat
|
29th September 2010, 21:04 | #69 |
This is my second home
ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007
Location: Conwy NORTH WALES
Posts: 11,094
Thanks: 512
Thanked 1,116 Times in 763 Posts
|
Mmm
And when engine needs max cooling on hot day it would boil over with a restricter in there. Any other ideas cos the 88 deg setup is still fine IMHO!
__________________
[SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block |
29th September 2010, 21:09 | #70 | |
Ex 75 Owner
75 Tourerless Join Date: Jul 2010
Location: Manchester
Posts: 2,147
Thanks: 60
Thanked 156 Times in 93 Posts
|
Quote:
Air gets to the AC condenser and the fan resistor through the main grille. So maybe a sliding air vent to the under-bumper grille? Similar idea to the air vents used on blocked-off chimney breasts. Ooooh, look! My genuine name for a piece of plumbing equipment has been moderated. For anyone who can't guess what the missing word is, it starts with c and has an o another c and a k in it. But not necessarily in that order. Funny breasts wasn't moderated.
__________________
Beyoncé's Green Light Used More Rubber 355188 of 355194 Last edited by Frank Incensed; 29th September 2010 at 21:13.. Reason: Explanation |
|
|
|