Weird Overheating Issues

Redmaestro · 4th November 2018, 15:59

Hi All

Apologies for what might end up as a long thread but I'll try and keep as short as I can.

I Live in Rhyl and headed out to the Welsh Mountain Zoo for a family day out. By the time I pulled off the A55 at Colwyn Bay (approx 20miles later on a 70 & 50mph duel carriageway), my temp shot right to the top with the red light on and fan whirring like crazy. I didn't have a safe place to stop so carefully carried on since we were 3/4mile away. Weirdly, the the temp fell to half way and fan stopped. Just as we got the gates, it temp shot up again & fan whirring.

After a couple of hrs, I checked the car over and noticed the cap wasn't tight but held the pressure so I assumed that it wasn't on tight enough. I quickly refilled with plain water, removed airlocks and tightened the cap as much as I dared to before rejoining my family.

Same happened when we got home. Temp normal but shot up after about 20miles, went down to normal and shot up again. When I got home I did spot a red leak under the engine - somewhere underneath the alternator I think.

Am i right in thinking its the water pump? I cant see it to check. Why would the temp fall to normal and rise again?

Thanks in advance

PS. Just re-filled coolant with water now the engine is cold and I've noticed its leaking out with the engine off. I'll try and add a photo but I cant remember how to.......[watch this space]

gazcaz · 4th November 2018, 16:07

Quote:

Originally Posted by Redmaestro

Hi All

Apologies for what might end up as a long thread but I'll try and keep as short as I can.

I Live in Rhyl and headed out to the Welsh Mountain Zoo for a family day out. By the time I pulled off the A55 at Colwyn Bay (approx 20miles later on a 70 & 50mph duel carriageway), my temp shot right to the top with the red light on and fan whirring like crazy. I didn't have a safe place to stop so carefully carried on since we were 3/4mile away. Weirdly, the the temp fell to half way and fan stopped. Just as we got the gates, it temp shot up again & fan whirring.

After a couple of hrs, I checked the car over and noticed the cap wasn't tight but held the pressure so I assumed that it wasn't on tight enough. I quickly refilled with plain water, removed airlocks and tightened the cap as much as I dared to before rejoining my family.

Same happened when we got home. Temp normal but shot up after about 20miles, went down to normal and shot up again. When I got home I did spot a red leak under the engine - somewhere underneath the alternator I think.

Am i right in thinking its the water pump? I cant see it to check. Why would the temp fall to normal and rise again?

Thanks in advance

Sender Unit , Fan Working ,Thermostat ? Also take of coolant cap run engine the small pipe at top of header tank i believe should be spitting coolant back into header tank, i believe if it is then the Water Pump is Okay...I may be wrong though..Water Pump failing i believe is the bearing collapsing or very rarely the impeller broken up but again hence small pipe check,,,, bearings normally make some sort of noise...When was it last replaced when belts were done ?

Redmaestro · 4th November 2018, 16:10

V is clear of any sign on leaks - I did change the thermostat and all the pipework in the summer and have had about 4months of driving long distances without any problems.

kaiser · 4th November 2018, 17:19

You are loosing water.
Thermostat, metal pipes in the bends, oil cooler, water pump, radiator, inlet manifold gaskets and the cap itself would be the most likely places to suspect.

Ravinder · 4th November 2018, 18:04

Sounds like it may be your thermostat gone. Common V6 issue, unfortunately.

Redmaestro · 4th November 2018, 19:13

I've added a pic to show where its leaking. It started to leak as my daughter was filling the coolant tank at what I think is the oil cooler(?).

Can this be bypassed, will it have a negative effect or will it need replacing?

trikey · 4th November 2018, 21:22

Quote:

Originally Posted by Redmaestro

I've added a pic to show where its leaking. It started to leak as my daughter was filling the coolant tank at what I think is the oil cooler(?).

Can this be bypassed, will it have a negative effect or will it need replacing?

Yes that's the oil cooler, you can bypass it, but check the water pump area first, a leaky pump can send water towards the oil cooler area.

Drivers front wheel off, and wheel arch liner out will give you a much better view (And if you do have to blank the cooler off, you will need access in there anyway)

Comfortably Numb · 4th November 2018, 23:20

If that isn't spillage from topping up, that is a significant leak. I have never had a water pump leak that badly, especially on a cold, stopped engine. You definitely need to isolate the leak before driving or risk running it short of coolant very quickly. Faulty thermostats don't leak, but the housing gasket can, but again, never seen one blow to that extent.

Redmaestro · 4th November 2018, 23:31

Thanks for the replies guys, now I'm certain it is the oil cooler. I've just been looking at the haynes manual to look at bypassing it with a view to replacing it after pay day.

I've just realized the reason why water is running to the back of the oil sump - my drive has a slight incline

Does anyone know the tube diameter I'll need to get to bypass the oil cooler?

4th November 2018, 15:59	#1
Redmaestro Avid contributor Join Date: Mar 2014 Posts: 106 Thanks: 11 Thanked 4 Times in 4 Posts	Weird Overheating Issues Hi All Apologies for what might end up as a long thread but I'll try and keep as short as I can. I Live in Rhyl and headed out to the Welsh Mountain Zoo for a family day out. By the time I pulled off the A55 at Colwyn Bay (approx 20miles later on a 70 & 50mph duel carriageway), my temp shot right to the top with the red light on and fan whirring like crazy. I didn't have a safe place to stop so carefully carried on since we were 3/4mile away. Weirdly, the the temp fell to half way and fan stopped. Just as we got the gates, it temp shot up again & fan whirring. After a couple of hrs, I checked the car over and noticed the cap wasn't tight but held the pressure so I assumed that it wasn't on tight enough. I quickly refilled with plain water, removed airlocks and tightened the cap as much as I dared to before rejoining my family. Same happened when we got home. Temp normal but shot up after about 20miles, went down to normal and shot up again. When I got home I did spot a red leak under the engine - somewhere underneath the alternator I think. Am i right in thinking its the water pump? I cant see it to check. Why would the temp fall to normal and rise again? Thanks in advance PS. Just re-filled coolant with water now the engine is cold and I've noticed its leaking out with the engine off. I'll try and add a photo but I cant remember how to.......[watch this space] Last edited by Redmaestro; 4th November 2018 at 19:09..

4th November 2018, 17:19	#4
kaiser This is my second home 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	You are loosing water. Thermostat, metal pipes in the bends, oil cooler, water pump, radiator, inlet manifold gaskets and the cap itself would be the most likely places to suspect. __________________ Worth his V8 in gold

4th November 2018, 18:04	#5
Ravinder This is my second home Rover 75 saloon x2, Rover 75 Tourer x2, Rover 220 Coupe Turbo Join Date: Aug 2010 Location: Kirkcaldy, Fife Posts: 9,036 Thanks: 2,278 Thanked 2,852 Times in 1,718 Posts	Sounds like it may be your thermostat gone. Common V6 issue, unfortunately. __________________ Wanted - Indian bride. Cash waiting. (All sorted - bargain) First name and forum name: Ravinder Rover 75 2.0 CDT Connoisseur SE 116 (160 remap) Royal Blue (JFM) This vehicle was the 50,481st 75 to run off the production line, out of 112,381 This vehicle was the 2,238th 75 CDT Connoisseur SE to be made out of 3,775 This vehicle was the 5,002nd 75 in Royal Blue (code: JFM) to be made out of 14,420 Royal Blue 75s

4th November 2018, 16:10	#3
Redmaestro Avid contributor Join Date: Mar 2014 Posts: 106 Thanks: 11 Thanked 4 Times in 4 Posts	V is clear of any sign on leaks - I did change the thermostat and all the pipework in the summer and have had about 4months of driving long distances without any problems.

4th November 2018, 19:13	#6
Redmaestro Avid contributor Join Date: Mar 2014 Posts: 106 Thanks: 11 Thanked 4 Times in 4 Posts	I've added a pic to show where its leaking. It started to leak as my daughter was filling the coolant tank at what I think is the oil cooler(?). Can this be bypassed, will it have a negative effect or will it need replacing?

4th November 2018, 23:20	#8
Comfortably Numb Posted a thing or two Rover 75 Saloon Join Date: Dec 2017 Location: Penrith Posts: 1,336 Thanks: 165 Thanked 303 Times in 241 Posts	If that isn't spillage from topping up, that is a significant leak. I have never had a water pump leak that badly, especially on a cold, stopped engine. You definitely need to isolate the leak before driving or risk running it short of coolant very quickly. Faulty thermostats don't leak, but the housing gasket can, but again, never seen one blow to that extent.

4th November 2018, 23:31	#9
Redmaestro Avid contributor Join Date: Mar 2014 Posts: 106 Thanks: 11 Thanked 4 Times in 4 Posts	Thanks for the replies guys, now I'm certain it is the oil cooler. I've just been looking at the haynes manual to look at bypassing it with a view to replacing it after pay day. I've just realized the reason why water is running to the back of the oil sump - my drive has a slight incline Does anyone know the tube diameter I'll need to get to bypass the oil cooler?