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 13th November 2019, 14:02   #1
Dave6
Newbie
 
2002 V6 2.5

Join Date: Apr 2019
Location: North West England
Posts: 20
Thanks: 2
Thanked 0 Times in 0 Posts
Default Operating Temperature

Hi all. Over recent months I have had new belts, thermostat, water pump, 2 speed fan and radiator. Temp is rising to 110 in stop start traffic before high speed fan brings it down. Operates at 92-97 in free flowing traffic. Getting cool air in passenger footwell and hot in drivers. Any idea what could be causing 110 operating temp and is this a problem?
Dave6 is offline   Reply With Quote
Old 13th November 2019, 14:10   #2
vitesse
Gets stuck in
 
Rover 75 Saloon Auto Conn

Join Date: Jul 2011
Location: Gävle, Sweden
Posts: 945
Thanks: 99
Thanked 239 Times in 201 Posts
Default

Sure you don't mean low speed fan? All fairly normal, the fan's doing it's job but your heater matrix is probably blocked.

Regards
vitesse is offline   Reply With Quote
Old 13th November 2019, 15:40   #3
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Rover 3500 Vanden Plas (1984).

Join Date: Mar 2007
Location: Middlesex
Posts: 16,302
Thanks: 874
Thanked 2,616 Times in 2,267 Posts
Default

Quote:
Originally Posted by vitesse View Post
All fairly normal, the fan's doing it's job ...
I beg to differ Mike. The slow speed fan should run well before 110 degrees is reached.
Quote:
Originally Posted by Dave6 View Post
Any idea what could be causing 110 operating temp and is this a problem?
Dave,

First of all and most importantly, your profile says that you haven't got a car. If we are to help you with any degree of accuracy you need to tell us which engine you have. This is essential information in order to diagnose cooling system problems. So please could you correct your profile straight away. Please don't tell us in a posting and leave your profile as it is. Many thanks.

To answer your question in general terms:
  • Fan resistor open circuit.
  • Air lock in cooling system.
  • Expansion tank cap seals flattened.
  • Other defect in cooling system preventing proper pressurisation.
  • K-seal.

Yes, it's a problem.

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.

Last edited by SD1too; 13th November 2019 at 15:43..
SD1too is offline   Reply With Quote
Old 13th November 2019, 15:47   #4
vitesse
Gets stuck in
 
Rover 75 Saloon Auto Conn

Join Date: Jul 2011
Location: Gävle, Sweden
Posts: 945
Thanks: 99
Thanked 239 Times in 201 Posts
Default

Sorry Simon misread the post to mean 100. Specsavers ?

Mike
vitesse is offline   Reply With Quote
Old 13th November 2019, 17:40   #5
Dave6
Newbie
 
2002 V6 2.5

Join Date: Apr 2019
Location: North West England
Posts: 20
Thanks: 2
Thanked 0 Times in 0 Posts
Default

2.5 V6. Cooling fans coming on at 100 and 106.in traffic. It will cool down to 92 via fans and driving. Then will go back to 105 plus when it hits traffic again. Sometimes it will go down from 105 to 92 in seconds. I've also had it sat on the driveway at home and the low speed fan at 100 soon cools it back to 92. So it seems to do this high temperature thing only whilst driving and when in lots of stop start driving.

Last edited by Dave6; 13th November 2019 at 17:47..
Dave6 is offline   Reply With Quote
Old 13th November 2019, 17:47   #6
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: 5,878
Thanks: 0
Thanked 632 Times in 501 Posts
Default

Quote:
Originally Posted by Dave6 View Post
2.5 V6. Cooling fans coming on at 100 and 106. It will cool down to 92 via fans and driving. Then will go back to 105 plus when it hits traffic again. Sometimes it will go down from 105 to 92 in seconds.
So what is the problem?
__________________
Worth his V8 in gold
kaiser is offline   Reply With Quote
Old 13th November 2019, 17:53   #7
Dave6
Newbie
 
2002 V6 2.5

Join Date: Apr 2019
Location: North West England
Posts: 20
Thanks: 2
Thanked 0 Times in 0 Posts
Default

It occurred to me that the temperature fluctuations were quite large and I would have thought that the slow speed fan would have kept things in check most of the time. Is it normal for the high speed fan to come on regularly in stop start traffic? I have also seen 110 which worried me a little.
Dave6 is offline   Reply With Quote
Old 13th November 2019, 18:11   #8
T-Cut
This is my second home
 
Rover75 and Mreg Corsa.

Join Date: Nov 2006
Location: Sumweer onat mote o'dust (Sagin)
Posts: 20,607
Thanks: 258
Thanked 3,067 Times in 2,507 Posts
Default

You've fitted a new 2-speed sytem in your KV6 I believe?


TC
T-Cut is offline   Reply With Quote
Old 13th November 2019, 18:13   #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: 5,878
Thanks: 0
Thanked 632 Times in 501 Posts
Default

Yes, normally the low speed fan should keep things in check. But with that, you can see 105 degrees.
I would try and clear all debris out from behind the fan motor. There most likely is quite a bit sitting in the "shadow" of the fan motor. That means no air is passing here.
How have you read your temperatures?
And how do you drive?. Coming off a highway and stopping in stop start traffic will mean a lot of pent up heat has to be released.
__________________
Worth his V8 in gold
kaiser is offline   Reply With Quote
Old 13th November 2019, 18:24   #10
Dave6
Newbie
 
2002 V6 2.5

Join Date: Apr 2019
Location: North West England
Posts: 20
Thanks: 2
Thanked 0 Times in 0 Posts
Default

Yes it's a new two speed fan that is coming on at the correct temperatures according to the OBD. The issue seems to arise when it hits heavy traffic after a fast drive on a motorway or similar. If I leave the car for a couple of hours it will soon display high temperatures again particularly in stop start traffic. If I leave it overnight and then go for a leisurely drive on A roads and little stop start traffic, then it will operate at about 92-96.
Dave6 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 +1. The time now is 10:32.


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