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 24th June 2018, 01:55   #1
pieterm
Regular poster
 
Rover 75 Connoisseur SE

Join Date: Mar 2018
Location: Point Cook, Australia
Posts: 83
Thanks: 69
Thanked 8 Times in 6 Posts
Default Random Coolant loss

My 2003 75 (done 160,000kms) is losing coolant 'somewhere'. Sometimes I'll drive 100+ kms and the levels remain constant. Other time I might drive 20kms and find the header tank empty. I check the level regularly and, when the level drops, it rarely needs more than two or three cupfuls to refill the header tank. There is no discolouration of the oil. No smoke out the back. Not drips under the engine. I can see no sign of any leak anywhere. I thought at first it might just be airlocks (having flushed the system to clean out the heater matrix) but this is the third time the level has suddenly dropped. Any help or guidance would be appreciated. Thankyou
pieterm is offline   Reply With Quote
Old 24th June 2018, 09:18   #2
Yorkshire GOC
I really should get out more.......
 
Yorkshire GOC's Avatar
 
Rover 75 connoisseur se v6 auto

Join Date: May 2014
Location: Hull
Posts: 2,058
Thanks: 1,842
Thanked 623 Times in 469 Posts
Default

Not a V6 driver but when i have unidentified coolant loss - i get my local garage to put her up on a ramp and run a coolant pressure test - in the past this has helped spot a failed IMG and a failing turbo hose. In the case of the IMG leak it took 2 hours to manifest itself on the ramp - engine had to be at a temp were expansion took place. With the IMG leak the only symptom was losing coolant and i only picked up on it initially as my fan was running after i parked up and normally this would not happen.

Also failure of the coolant plastic hose and thermostat O rings in the V6 have been widely reported - but generally the coolant pools in the V of the engine.
__________________
She came off the Longbridge Line on 20-05-2003

The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.
Yorkshire GOC is online now   Reply With Quote
Old 24th June 2018, 10:41   #3
Ratty
I'll do it Dreckly
 
Ratty's Avatar
 
MG ZTT CDTI Honda Jazz 1.4 Auto

Join Date: Oct 2012
Location: Cornwall
Posts: 2,166
Thanks: 1,341
Thanked 888 Times in 594 Posts
Default

Quote:
Originally Posted by pieterm View Post
My 2003 75 (done 160,000kms) is losing coolant 'somewhere'. Sometimes I'll drive 100+ kms and the levels remain constant. Other time I might drive 20kms and find the header tank empty. I check the level regularly and, when the level drops, it rarely needs more than two or three cupfuls to refill the header tank. There is no discolouration of the oil. No smoke out the back. Not drips under the engine. I can see no sign of any leak anywhere. I thought at first it might just be airlocks (having flushed the system to clean out the heater matrix) but this is the third time the level has suddenly dropped. Any help or guidance would be appreciated. Thankyou
Your not overfilling the header tank? full level is near the bottom of tank.
__________________
Membership Number 001426
I'll do it Drekley.
Regards Allen.
Ratty is offline   Reply With Quote
Old 26th June 2018, 03:08   #4
pieterm
Regular poster
 
Rover 75 Connoisseur SE

Join Date: Mar 2018
Location: Point Cook, Australia
Posts: 83
Thanks: 69
Thanked 8 Times in 6 Posts
Default

Thanks for your advice but, sadly, no reliable trustworthy garages close to my place. If I can't find the problem, then I guess a bit of travelling to get it all checked out may be necessary
pieterm is offline   Reply With Quote
Old 26th June 2018, 03:14   #5
pieterm
Regular poster
 
Rover 75 Connoisseur SE

Join Date: Mar 2018
Location: Point Cook, Australia
Posts: 83
Thanks: 69
Thanked 8 Times in 6 Posts
Default

Interesting point. Of course trying so see the level isn't that easy either. But, using a measure, it does appear that it might be overfilled. I've been using top of the molded tabs on the inside of the tank as a guide but note that to be higher than the maximum level stamped on the outside of the header tank. Yesterday my drive took me 80kms and I noted a slight drop in level. From what I can tell, the maximum level appears to be almost the bottom of the header tank. Is that right? Does the high mark refer to when the engine is hot and the low mark when it is cold? I did read on one of the posts that these cars do tend to use a bit of water. All very confusing for a novice like me
pieterm is offline   Reply With Quote
Old 26th June 2018, 06:29   #6
Lord of Hog
Gets stuck in
 
Lord of Hog's Avatar
 
Rover 75 2.5 V6 in Wedgwood Blue

Join Date: Dec 2015
Location: Felbridge, East Grinstead
Posts: 982
Thanks: 250
Thanked 294 Times in 206 Posts
Default

It's worth re-visiting the air-lock idea. Unless you re-fill these things absolutely by the book then air can hang around in the system for ever and a day. Another possibility is a small leak close to something warm, meaning any escaping fluid evaporates before it gets the chance to drip. I've had them both and they can be really trying before you get to that slap on the head and "ahaaaaa!" moment.
__________________


Conformity is not morality.
Consensus is not truth.
Lord of Hog is offline   Reply With Quote
Old 26th June 2018, 10:07   #7
Arctic
Give to Learn
 
Arctic's Avatar
 
Freelander 2

Join Date: Aug 2010
Location: West Midlands
Posts: 18,651
Thanks: 1,155
Thanked 6,407 Times in 3,874 Posts
Default

Hi Pieter
photo below of the level you should be looking for in the coolant tank.

First photo is a little low to show the step inside the tank, second photo is how it should be also check the O-rings on the coolant cap if they are flat and not domed shape they need changing, use Viton ones. Arctic
Attached Images
File Type: jpg SDC11889.jpg (111.2 KB, 45 views)
File Type: jpg coolant level (2).jpg (105.4 KB, 45 views)
__________________
Arctic
Givology Learn to Give
Everything is Achievable

ad altiora tendo.

Check out our Nano meet dates
http://www.midlandsnanomeets.co.uk/

http://www.the75andztclub.co.uk/index.php?thepage=howto

" You do the work , we supply the expertise "
Arctic is offline   Reply With Quote
Old 26th June 2018, 22:45   #8
pieterm
Regular poster
 
Rover 75 Connoisseur SE

Join Date: Mar 2018
Location: Point Cook, Australia
Posts: 83
Thanks: 69
Thanked 8 Times in 6 Posts
Default

Quote:
Originally Posted by Lord of Hog View Post
It's worth re-visiting the air-lock idea. Unless you re-fill these things absolutely by the book then air can hang around in the system for ever and a day. Another possibility is a small leak close to something warm, meaning any escaping fluid evaporates before it gets the chance to drip. I've had them both and they can be really trying before you get to that slap on the head and "ahaaaaa!" moment.
Thanks. Looks like some rechecking in order
pieterm is offline   Reply With Quote
Old 26th June 2018, 22:53   #9
pieterm
Regular poster
 
Rover 75 Connoisseur SE

Join Date: Mar 2018
Location: Point Cook, Australia
Posts: 83
Thanks: 69
Thanked 8 Times in 6 Posts
Default

Quote:
Originally Posted by Arctic View Post
Hi Pieter
photo below of the level you should be looking for in the coolant tank.

First photo is a little low to show the step inside the tank, second photo is how it should be also check the O-rings on the coolant cap if they are flat and not domed shape they need changing, use Viton ones. Arctic
Thanks Arctic ... Now we're getting somewhere ... thanks for taking the trouble to send photos ... I never saw the max level inside the tank ... only mark I saw was on the outside. That's the trouble when working in the shadows of an overcrowded garage! On the basis of your photos, I definitely am overfilling ... and get that 'hiss' sound when opening the cap, suggesting a vacuum. The coolant cap O-rings also look good. So maybe there is something else I should be looking for where coolant may be escaping. It's one of those annoying things. But at least I now know where the 'max' level is LOL. Thanks again
pieterm is offline   Reply With Quote
Old 27th June 2018, 09:08   #10
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

Pieter,

Renewing the expansion cap seals on my car stopped persistent small variations in coolant level. These seals become compressed after many years' service so I would recommend renewal.

After your work to the heater matrix did you refill the cooling system using the official MGR method which involves raising the expansion tank?

Have you looked into the 'V' to check for a leak from the 'O' ring seals there?

Have you performed the 'demist test' to check that your radiator fan is operational on the slow speed?

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too 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 16:22.


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