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 Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 19th October 2019, 21:58   #21
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model.

Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,265
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
Exclamation Pete, please note.

I am sorry, I cannot let these remarks remain uncorrected.
Quote:
Originally Posted by kaiser View Post
The cooling system is self bleeding ...
No it isn't. There is a procedure quoted by the manufacturer about which you might have read.
Quote:
Originally Posted by kaiser View Post
I would leave the bleed screw well alone. It is likely to break ...
It will break only if it is overtightened or otherwise treated carelessly.
Quote:
Originally Posted by kaiser View Post
In town it will go to 102 to 105, depending on ambient temperature ...
Ambient temperature has nothing to do with it. The fan should trigger at 100 degrees in all conditions, not 102 or 105.

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too is online now   Reply With Quote
Old 20th October 2019, 08:39   #22
vitesse
I really should get out more.......
 
Rover 75 Saloon

Join Date: Jul 2011
Location: Gävle
Posts: 2,515
Thanks: 395
Thanked 823 Times in 652 Posts
Default

This time Simon and I agree, at least regarding the initial filling sequence, our latest V6 was anything but self-bleeding. (post 7). I can however accept that it should be self-bleeding and purge the system of air once filled but now we’re talking about minute quantities of air. Perhaps Kaiser meant under normal operation?

Regards
vitesse is offline   Reply With Quote
Old 20th October 2019, 12:58   #23
racing green rover
Avid contributor
 
MG ZT

Join Date: Sep 2014
Location: Westhoughton Bolton
Posts: 233
Thanks: 153
Thanked 16 Times in 14 Posts
Default

When everyone says the fan should drop the temperature to 95 quickly mine always takes about a minute- minute and half even when the cooling system was working properly.
racing green rover is offline   Reply With Quote
Old 20th October 2019, 13:10   #24
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model.

Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,265
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
Default

It depends how "quickly" is defined. I haven't timed my car but I'd judge that your quoted one to one and a half minutes isn't too wide of the mark. The official temperature for the fan to stop running is 96 degrees not 95.

Remember also Pete that your cooling system is not perfectly sealed. This will cause temperature instability. When you carry out the necessary repairs you will notice an improvement.

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too is online now   Reply With Quote
Old 20th October 2019, 13:16   #25
T-Cut
This is my second home
 
Rover75 and Mreg Corsa.

Join Date: Nov 2006
Location: Sumweer onat mote o'dust (Sagin)
Posts: 21,751
Thanks: 341
Thanked 3,660 Times in 2,924 Posts
Default

Quote:
Originally Posted by racing green rover View Post
When i checked the coolant level the next day it was halfway up the expansion tank whereas the day before i had to add a cupfull of water to bring it to the max indicator

If the system was stone cold on both occasions, I'd like to hear an explanation of that.


TC
T-Cut is offline   Reply With Quote
Old 20th October 2019, 13:31   #26
racing green rover
Avid contributor
 
MG ZT

Join Date: Sep 2014
Location: Westhoughton Bolton
Posts: 233
Thanks: 153
Thanked 16 Times in 14 Posts
Default

Yes stone cold on both occasions there wasn't an hiss when i undid the expansion tank cap nor was there any bubbles or smelling of exhaust gases. Iv had a combustion dye test done on the coolant not long ago and it stayed blue.
Fan on my car cuts off at 95

Last edited by racing green rover; 20th October 2019 at 13:41..
racing green rover is offline   Reply With Quote
Old 20th October 2019, 13:59   #27
T-Cut
This is my second home
 
Rover75 and Mreg Corsa.

Join Date: Nov 2006
Location: Sumweer onat mote o'dust (Sagin)
Posts: 21,751
Thanks: 341
Thanked 3,660 Times in 2,924 Posts
Default

The coolant level change really does need explaining.


TC
T-Cut is offline   Reply With Quote
Old 20th October 2019, 14:22   #28
racing green rover
Avid contributor
 
MG ZT

Join Date: Sep 2014
Location: Westhoughton Bolton
Posts: 233
Thanks: 153
Thanked 16 Times in 14 Posts
Default

Yes it does i cant do nothing until the replacement bottom hose comes next week so I'll update when I've bled it again. Although once i undid the expansion cap when the engine was still hot and there was no pressure in the tank even when it was warm

Last edited by racing green rover; 20th October 2019 at 14:28..
racing green rover is offline   Reply With Quote
Old 20th October 2019, 15:14   #29
kaiser
This is my second home
 
kaiser's Avatar
 
75 Tourer 2.5 Auto, 1.8T, 75V8ZT

Join Date: Jun 2007
Location: Johannesburg ZA
Posts: 6,200
Thanks: 1
Thanked 859 Times in 613 Posts
Default

Quote:
Originally Posted by SD1too View Post
I am sorry, I cannot let these remarks remain uncorrected.

No it isn't. There is a procedure quoted by the manufacturer about which you might have read.

It will break only if it is overtightened or otherwise treated carelessly.

Ambient temperature has nothing to do with it. The fan should trigger at 100 degrees in all conditions, not 102 or 105.

Simon
The air pocket in a cooling system will settle in the expansion box, that applies to the V6 as well. A couple of top ups and the system is filled fully. The cooling system is self bleeding without any doubt.
The bleed screw is plastic. They get tired. Luckily some people seem to get thermostat housings and other plastic bits that will never, ever break. For others, you might not be so lucky.
As for the temperature in town, it has a lot to do with ambient temperatures. In some cases with the heater on, the fan might not come on at all.
As for the temperatures you can see, take my word for it, you do see 102 to 105. If the fan triggers at 100, it does not mean you will never see over 100.
__________________
Worth his V8 in gold
kaiser is offline   Reply With Quote
Old 20th October 2019, 15:27   #30
kaiser
This is my second home
 
kaiser's Avatar
 
75 Tourer 2.5 Auto, 1.8T, 75V8ZT

Join Date: Jun 2007
Location: Johannesburg ZA
Posts: 6,200
Thanks: 1
Thanked 859 Times in 613 Posts
Default

Quote:
Originally Posted by racing green rover View Post
Yes stone cold on both occasions there wasn't an hiss when i undid the expansion tank cap nor was there any bubbles or smelling of exhaust gases. Iv had a combustion dye test done on the coolant not long ago and it stayed blue.
Fan on my car cuts off at 95
My self installed temperature gauge on the incoming cooling line started fine, but dropped slowly, the heater got colder and the engine got hot. I stopped and checked the expansion box. It was full, no pressure in the system. Top of engine cold but in the V it was sizzling. That happened a coupe of times, and in spite of water in the expansion box, it could take quite a bit of water when you poured it in. It was clear I was losing water. Eventually I blew into the expansion box and the water disappeared into the cooling system, and gurgling and steam ensued.
Eventually I found the problem, namely two minuscule holes in the two metal pipes in front of the cooling system. They were really tiny, only really a small spot of rust, and they did not leak at all times. They must have sprayed a fine mist that I did not notice once the engine was started and got up to temperature.
I bypassed the oil cooler and the two pipes, and the problem was gone. I later removed the oil cooler all together.
I thought at that stage that it was a head gasket!
It was luckily not.
__________________
Worth his V8 in gold
kaiser is offline   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. The time now is 16:09.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd