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 20th February 2018, 00:06   #1
BaroqueMoon
Gets stuck in
 
Rover 75 Saloon

Join Date: Jul 2012
Location: Ballarat
Posts: 937
Thanks: 576
Thanked 114 Times in 99 Posts
Default Is my 2.5 V6 cooked?

I have had the thermostat replaced about two years ago as it was running too cold. It has been perfect ever since. That is until a few days ago.
Driving at highway speeds all was normal then as we slowed to a crawl for road works it started overheating.
Coolant was forcing its way out of the cap.
I topped it up with water and after about 15 minutes of driving it happened again. I got it towed home.

I have drained the system completely, added radiator flush and at idle it runs for twenty minuted until the temp gets too high and I have to shut it down.
I have flushed the system 3 times now.
It still overheats after 20 minutes at idle.

The fan works as it should.
I replaced the O rings in the cap with viton ones about four years ago and upon inspection they still seem perfect.

Could it be a failed water pump?
Could the cap be the problem?
Could the head gasket be the issue?
Could it be cooked???

Any advice gratefully accepted.

Argh.
__________________
Love my 75 and it loves me
Membership Number 1703

This vehicle was the 82,624th 75 to run off the production line, out of 112,381
This vehicle was the 6,161st 75 2.5 V6 Contemporary to be made out of 8,214
This vehicle was the 9,755th 75 in White Gold Metallic (code: GMN) to be made out of 12,251 White Gold Metallic 75s

Last edited by BaroqueMoon; 20th February 2018 at 00:23..
BaroqueMoon is offline   Reply With Quote
Old 20th February 2018, 06:28   #2
rustymotor
Posted a thing or two
 
rustymotor's Avatar
 
Rover 75 Tourer

Join Date: May 2017
Location: Hull
Posts: 1,848
Thanks: 216
Thanked 432 Times in 340 Posts
Default

Hi, thermostat Kaput perhaps appears to be common on the KV6 engine.
rustymotor is offline   Reply With Quote
Old 20th February 2018, 06:39   #3
BaroqueMoon
Gets stuck in
 
Rover 75 Saloon

Join Date: Jul 2012
Location: Ballarat
Posts: 937
Thanks: 576
Thanked 114 Times in 99 Posts
Default

Replacing the thermostat I can do. I hope that's the issue.
I will wait for a few more ideas before I start on it though.

Thanks for the input. I really appreciate it.
__________________
Love my 75 and it loves me
Membership Number 1703

This vehicle was the 82,624th 75 to run off the production line, out of 112,381
This vehicle was the 6,161st 75 2.5 V6 Contemporary to be made out of 8,214
This vehicle was the 9,755th 75 in White Gold Metallic (code: GMN) to be made out of 12,251 White Gold Metallic 75s
BaroqueMoon is offline   Reply With Quote
Old 20th February 2018, 07:07   #4
rustymotor
Posted a thing or two
 
rustymotor's Avatar
 
Rover 75 Tourer

Join Date: May 2017
Location: Hull
Posts: 1,848
Thanks: 216
Thanked 432 Times in 340 Posts
Default

Hi, yes could be a number of things like fan not running etc hope it's a simple fix for you. Post here
rustymotor is offline   Reply With Quote
Old 20th February 2018, 10:39   #5
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 Matthew.
How much coolant do you have in the coolant header tank, can you just about see the max mark looking into the tank?

Reason for the above question is if to much coolant in the header tank you will have no expansion, I would also change the coolant cap even though you have changed the O-rings sometime the cap can be faulty.

Then maybe look to the thermostat as the problem.
Attached Images
File Type: jpg coolant level (2).jpg (105.4 KB, 35 views)
File Type: jpg SDC11889.jpg (111.2 KB, 38 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 20th February 2018, 10:54   #6
hrissim
Gets stuck in
 
75 MK1 2.5 V6 Saloon

Join Date: May 2017
Location: Samokov
Posts: 781
Thanks: 372
Thanked 423 Times in 240 Posts
Default

Quote:
Originally Posted by Arctic View Post
Hi Matthew.
How much coolant do you have in the coolant header tank, can you just about see the max mark looking into the tank?

Reason for the above question is if to much coolant in the header tank you will have no expansion, I would also change the coolant cap even though you have changed the O-rings sometime the cap can be faulty.

Then maybe look to the thermostat as the problem.
Ohh,yes!
Or there is some air pocket in the system?
The cup has some pressure valve on it. If it is in fault this will uprise the pressure in the system as a result thrown up the liquid thru the small pipe.
__________________
Don`t drive faster than your guardian-angel can fly!
hrissim is offline   Reply With Quote
Old 20th February 2018, 11:37   #7
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 BaroqueMoon View Post
The fan works as it should.
What tests did you do?

TC
T-Cut is offline   Reply With Quote
Old 20th February 2018, 13:28   #8
egremont
Loves to post
 
egremont's Avatar
 
Rover 75 Connoisseur SE. Auto. Saloon. SE

Join Date: Apr 2009
Location: Melbourne
Posts: 458
Thanks: 163
Thanked 198 Times in 70 Posts
Default

Hi Matthew,
Sorry to learn of your problem.
A friend speaks highly of the Ballarat based mechanic that has serviced their 75 for years.
Send me a PM if you would like his details.
Regards
Bruce.
egremont is offline   Reply With Quote
Old 20th February 2018, 18:45   #9
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

Coolant leak.
Thermostat stuck
Fan not operating correctly
Radiator cap faulty.

These are the things that come to mind

If you are unlucky, head gasket failure.
__________________
Worth his V8 in gold
kaiser is offline   Reply With Quote
Old 21st February 2018, 13:19   #10
genpk
Posted a thing or two
 
Rover 75 Saloon MGZT

Join Date: Jul 2012
Location: Perth, AUSTRALIA
Posts: 1,662
Thanks: 3
Thanked 461 Times in 299 Posts
Default

Been through all this, Kaiser’s comments are correct.
You need to eliminate all those items.
Make sure the coolant in the tank is at the right level.
Undo the bleed screw in the top radiator hose,run the engine up to temp and see if air is coming out , replace bleed screw when water only is coming out.
Try the aircon test re activating the cooling fan.
If that’s all working you know if overheating is happening it’s either a faulty thermostat or somthing else .
I’d say the odds of it being a faulty water pump are slim as they usually die by leaking seals rather than the intervals seizing up.
genpk 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 22:32.


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