Fan struggling to reduce temperature unless revved kv6 - Page 2

racing green rover · 23rd August 2020, 21:37

Yes Simon I have flushed the radiator and had the hoses off and the flow is ok both the top hose and the bottom hose was just warm today you could easily squish them the heater is still blowing red hot though.
Cheers

vitesse · 23rd August 2020, 21:47

Simon's not going to like this but we've had this discussion before and it helped me: while the engine is running ease the bleed screw - what comes out, water or air?

I'm with T-Cut, I still think you have an airlock.

Regards

racing green rover · 23rd August 2020, 21:50

I've not done that yet I'm going to bleed it again tomorrow providing the weather holds up. I'll post back results

SD1too · 23rd August 2020, 22:05

Quote:

Originally Posted by racing green rover

... the flow is ok both the top hose and the bottom hose was just warm today .... the heater is still blowing red hot though.

In which case, having ruled out the radiator, I would turn your attention to the oil cooler.

I agree with the others about an air lock but you have already clearly said that you've refilled and bled it according to the MG Rover procedure. Therefore, to my way of thinking, something else must be responsible.

Simon

racing green rover · 23rd August 2020, 22:07

I have recently put a brand new oil cooler on.

SD1too · 23rd August 2020, 22:15

OK, so if there's no restriction to flow through the radiator and oil cooler then the next possibility is the thermostat. Has K-seal sealed it's movement in some way? Don't tell me, you've renewed that as well?

Simon

racing green rover · 23rd August 2020, 22:24

Yes I replaced that last year when I was flushing the system the original thermostat when I took it out wasn't gummed up whatsoever

SD1too · 23rd August 2020, 22:45

See what I mean about K-sealed engines defying logical diagnosis?

You have low temperature hoses when they should be hot and your fan is failing to cool the engine. At the same time you believe that there's nothing wrong with your radiator, oil cooler or thermostat.

You've said that the heater circuit is hot yet the radiator circuit isn't; I'm struggling to understand that.

Simon

Edit: Should we be considering Colin_NI's suggestion?

racing green rover · 23rd August 2020, 23:01

I know it's a strange one I'm just going to bleed it again tomorrow and see what happens, I'm going to be putting a new engine in anyway as this one has a knock I only need to get the cooling system better so I can do a 3hr drive in two week

maxi_crawf · 24th August 2020, 15:13

It can help if the front of the car is raised (if it's an air lock) by a few inches, don't ask me why I don't know but it does, not permanently of course just when your're topping up

23rd August 2020, 22:15	#16
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,344 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	OK, so if there's no restriction to flow through the radiator and oil cooler then the next possibility is the thermostat. Has K-seal sealed it's movement in some way? Don't tell me, you've renewed that as well? Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

23rd August 2020, 22:45	#18
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,344 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	See what I mean about K-sealed engines defying logical diagnosis? You have low temperature hoses when they should be hot and your fan is failing to cool the engine. At the same time you believe that there's nothing wrong with your radiator, oil cooler or thermostat. You've said that the heater circuit is hot yet the radiator circuit isn't; I'm struggling to understand that. Simon Edit: Should we be considering Colin_NI's suggestion? __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce. Last edited by SD1too; 23rd August 2020 at 22:52..

23rd August 2020, 21:37	#11
racing green rover Avid contributor MG ZT Join Date: Sep 2014 Location: Westhoughton Bolton Posts: 233 Thanks: 153 Thanked 16 Times in 14 Posts	Yes Simon I have flushed the radiator and had the hoses off and the flow is ok both the top hose and the bottom hose was just warm today you could easily squish them the heater is still blowing red hot though. Cheers

23rd August 2020, 21:47	#12
vitesse I really should get out more....... Rover 75 Saloon Join Date: Jul 2011 Location: Gävle Posts: 2,528 Thanks: 395 Thanked 823 Times in 652 Posts	Simon's not going to like this but we've had this discussion before and it helped me: while the engine is running ease the bleed screw - what comes out, water or air? I'm with T-Cut, I still think you have an airlock. Regards

23rd August 2020, 21:50	#13
racing green rover Avid contributor MG ZT Join Date: Sep 2014 Location: Westhoughton Bolton Posts: 233 Thanks: 153 Thanked 16 Times in 14 Posts	I've not done that yet I'm going to bleed it again tomorrow providing the weather holds up. I'll post back results

23rd August 2020, 22:07	#15
racing green rover Avid contributor MG ZT Join Date: Sep 2014 Location: Westhoughton Bolton Posts: 233 Thanks: 153 Thanked 16 Times in 14 Posts	I have recently put a brand new oil cooler on.

23rd August 2020, 22:24	#17
racing green rover Avid contributor MG ZT Join Date: Sep 2014 Location: Westhoughton Bolton Posts: 233 Thanks: 153 Thanked 16 Times in 14 Posts	Yes I replaced that last year when I was flushing the system the original thermostat when I took it out wasn't gummed up whatsoever

23rd August 2020, 23:01	#19
racing green rover Avid contributor MG ZT Join Date: Sep 2014 Location: Westhoughton Bolton Posts: 233 Thanks: 153 Thanked 16 Times in 14 Posts	I know it's a strange one I'm just going to bleed it again tomorrow and see what happens, I'm going to be putting a new engine in anyway as this one has a knock I only need to get the cooling system better so I can do a 3hr drive in two week

24th August 2020, 15:13	#20
maxi_crawf Posted a thing or two R75 Saloon Conn CDT SE, MG ZT190+ Join Date: Nov 2006 Location: Kingston-upon-Hull Posts: 1,960 Thanks: 823 Thanked 426 Times in 274 Posts	It can help if the front of the car is raised (if it's an air lock) by a few inches, don't ask me why I don't know but it does, not permanently of course just when your're topping up