Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > Technical Help Forum
Register FAQ Image Gallery Members List Calendar Search Today's Posts Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 12th December 2010, 23:00   #501
rossocorsa
Posted a thing or two
 
None

Join Date: Feb 2010
Location: GRIMSBY
Posts: 1,247
Thanks: 0
Thanked 1 Time in 1 Post
Default

looking at this diagram


can anyone expalin how coolant expansion is accommodated when both stats are closed? that does look worrying for that reason I feel that the stat should be in the outlet not inlet(????)
rossocorsa is offline   Reply With Quote
Old 12th December 2010, 23:21   #502
BigRuss
Premium Trader
 
BigRuss's Avatar
 
75 CDT Tourer,2.5 Launch Saloon, Omipro MG/Rover (T4)

Join Date: Jul 2007
Location: Liversedge, West Yorkshire
Posts: 4,900
Thanks: 501
Thanked 871 Times in 433 Posts
Default

It's not an ideal thing to have two thermostats, it would be far better to remove the old one then fit the remote housing, however the old stat being weaker should open very quickly after the new stat opened.

I don't see any issues with thermal expansion from what I can see it should be unaffected.
__________________


Replacement Key Service
BigRuss's Replacement Key Prices

Full T4 Testbook diagnostics available.
Diesel ECU repair and replacement.
Options enabled or disabled as required.
Diesel X-Power 135 and 160bhp, Rover 1.8T 150 to 160
MG 160 V6 to 177 upgrades available
P.M. for details.
BigRuss is offline   Reply With Quote
Old 13th December 2010, 00:20   #503
Jules
This is my second home
 
Jules's Avatar
 
ZT 260 SE Twilight and 10 other 75 ZT's :O

Join Date: Jan 2007
Location: Conwy NORTH WALES Tel 07831 457011
Posts: 11,424
Thanks: 513
Thanked 1,054 Times in 729 Posts
Default

So long as the additional Stat has the bleed hole drilled, I don't see a problem as the OEM Stat is fitted with a ball valve anyway. (This allows fluid to expand or contract either way)

But Guys, don't expect the remote stat to run as hot as a correctly functioning OEM type.

88 deg on the cool return coolant through the OEM Stat is bound to give hotter results than 88 deg in the outlet from the cylinder head area.

Don't get me wrong, the Remote stat is a good economical mod but I fear will never work as well as the BMW design.
For that reason I am still offering a fitting service for both types!

Two BMW Stat install jobs have just come in for the New Year ..............for my sins
__________________

T4 Testbook Sessions, 75 ZT General Servicing
Cooling Fan motors complete ~ Cooling fan resistor upgrades ~ PCV Valve/Filter ~ Strut bearings ~ Intercooler Viton O rings

Jules Forum Shop http://www.the75andztclub.co.uk/foru...splay.php?f=74
eBay Shop http://myworld.ebay.co.uk/rover75ztspecialist

NORTH WALES 75 ZT Specialist


Newbies do now!!
1. Plenum drains..all 3 or 4 year dependent
2. Cooling fan..All speeds functioning
3. Bonnet cable divider block
Jules is offline   Reply With Quote
Old 13th December 2010, 08:18   #504
t_i_m
Avid contributor
 
ZT-T CDTi

Join Date: Oct 2007
Location: Cheshire
Posts: 220
Thanks: 3
Thanked 2 Times in 2 Posts
Default

Quote:
Originally Posted by BigRuss View Post
It's not an ideal thing to have two thermostats, it would be far better to remove the old one then fit the remote housing, however the old stat being weaker should open very quickly after the new stat opened.

I don't see any issues with thermal expansion from what I can see it should be unaffected.
I would be very wary removing the old stat completely I imagine it will also be acting a flow restrictor to create the correct pressure in the block which is why the thermostat is positioned where it is.

On mine coolant was returning to the header tank immediately (with the in-line stat in place).

I had 82-84deg on a 20 mile dual carriageway run this morning, it went upto 88deg up a hill when the stat clearly opened and dropped to 86deg (load was increasing at the time). After reaching 'full' temperature and everything fully warmed up I saw 87 deg a few times even at slower speeds.

Overall its an improvement for me but like Jules says its not as effective as replacing the OEM stat.
t_i_m is offline   Reply With Quote
Old 13th December 2010, 08:44   #505
Mintee
Posted a thing or two
 
Rover 75 Tourer

Join Date: Oct 2009
Location: .
Posts: 1,056
Thanks: 174
Thanked 48 Times in 42 Posts
Default

Quote:
Originally Posted by t_i_m View Post
I would be very wary removing the old stat completely I imagine it will also be acting a flow restrictor to create the correct pressure in the block which is why the thermostat is positioned where it is.
If you are going to remove the old 'stat completely then you might as well fit an OEM on as a replacement. The effort involved would be the same and they even cost a little less than the in-line version!
Quote:
Originally Posted by t_i_m View Post
I had 82-84deg on a 20 mile dual carriageway run this morning, it went upto 88deg up a hill when the stat clearly opened and dropped to 86deg (load was increasing at the time). After reaching 'full' temperature and everything fully warmed up I saw 87 deg a few times even at slower speeds.

Overall its an improvement for me but like Jules says its not as effective as replacing the OEM stat.
It sounds as if you are running a few degrees cooler than the Chevy 'stat as I know that mine opens (using the dash OBD) when it hits 92C and but more often it sits @87C. I really recommend that someone with these 88C 'stats trys fitting one that is designed to open a little later if they want to run a few degrees hotter all the time.
Mintee is online now   Reply With Quote
Old 13th December 2010, 08:46   #506
wuzerk
Passed Away
 
Rover 75 CDT 03 auto Conn. SE

Join Date: May 2009
Location: London
Posts: 2,887
Thanks: 104
Thanked 255 Times in 205 Posts
Default Update

I did some testing on the British In line thermostat system today and compared it with the Chevy 'stat.
The problem with the British one is that he has drilled a quite large bleed hole in the thermostat when it does not need a bleed hole as there is one built in on the edge of the opening plate! The Chevy 'stat has the same built in hole so does not need an additional hole either which I found out the hard way! This means of course that too much water is bleeding through to the rad lowering the available temperature. The problem is how to block up the unnecessary hole?
not enough room for a pop rivet so I suspect soldering is the only way to block it.


There are no problems caused by leaving the original early opening stat in position. The whole point of my experiments was how to attain a good running temperature without having to remove the original.

Last edited by wuzerk; 13th December 2010 at 09:14..
wuzerk is offline   Reply With Quote
Old 13th December 2010, 08:54   #507
Mintee
Posted a thing or two
 
Rover 75 Tourer

Join Date: Oct 2009
Location: .
Posts: 1,056
Thanks: 174
Thanked 48 Times in 42 Posts
Default

Quote:
Originally Posted by wuzerk View Post
The problem is how to block up the unnecessary hole?
not enough room for a pop rivet so I suspect soldering is the only way to block it.
Wouldn't it be easier and quicker to just fit another 'stat?
Mintee is online now   Reply With Quote
Old 13th December 2010, 09:04   #508
wuzerk
Passed Away
 
Rover 75 CDT 03 auto Conn. SE

Join Date: May 2009
Location: London
Posts: 2,887
Thanks: 104
Thanked 255 Times in 205 Posts
Default Holy stat

I have e mailed the British supplier re the hole but it is probably too late for everybody now.
I tried standing the housing on end with the 1 1/2" uppermost and pouring water into it. It drained through in less than 10 seconds which is too fast.
Unless somebody comes up with a simple hole blocking idea (like epoxy putty) then a new stat will be the answer. My spare Chevy stat physically fits but will need some gasket goo around the recess where it sits.

I am not very impressed by the quality of the 'British' stat.

Last edited by wuzerk; 13th December 2010 at 09:10..
wuzerk is offline   Reply With Quote
Old 13th December 2010, 09:04   #509
rossocorsa
Posted a thing or two
 
None

Join Date: Feb 2010
Location: GRIMSBY
Posts: 1,247
Thanks: 0
Thanked 1 Time in 1 Post
Default

did no one tell him not to drill an extra hole? I think we already concluded that the heater acts as a by pass anyway if it fits I think I will try the vauxhall opel 92 degree stat that someone mentioned maybe not a lot of extra help in winter but might improve efficiency in summer

any idea what car the stat in it came from?
rossocorsa is offline   Reply With Quote
Old 13th December 2010, 10:08   #510
Mintee
Posted a thing or two
 
Rover 75 Tourer

Join Date: Oct 2009
Location: .
Posts: 1,056
Thanks: 174
Thanked 48 Times in 42 Posts
Default

Quote:
Originally Posted by rossocorsa View Post
did no one tell him not to drill an extra hole?
Who told them to drill an extra hole?
Mintee is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 08:43.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright 2006-2019, The Rover 75 & MG ZT Owners Club Ltd