Discussion
No it’s easy.
Just remove the bottom rad hose and drain it away.
Usually some coolant stays in the heater matrix so you could Jack the rear of the car up to assist removing it but not really necessary.
Bleeding the system can be an issue but only if you do it wrong.
Turn heater control knob to fully hot.
Firstly make up a long pipe with a plastic insert into it that can connect to the 6 inch length of pipe that has a blanking bolt or Allen bolt inserted into it in the inlet manifold on the left hand side of the engine. Remove bolt and connect the long pipe into it.
That pipe should now be placed into a container you make up that screws or push fits into the swirl pot.
Fill the system from the swirl pot just behind the exhaust Y piece in front of the engine slowly until full via the container screwed into swirl pot so you have coolant higher than the inlet manifold on top of the engine.
Then open bleed valve in radiator until a constant flow comes out and nip it up again.
Start engine keeping coolant topped up in your container never letting it become empty ot you’ll draw air in.
Keep the made up smaller pipe submerged in that container.
Feel rad top hose gets warm which indicates stat has opened and Rev the engine to push water around, squeeze top hose which can help force any air out.
Watch the water circulate and any air in the inlet manifold should come out through the smaller pipe via bubbles into the container and when only coolant comes through that pipe you have successfully bled the whole system.
Place bolt in smaller pipe and remove container in swirl pot. The swirl pot should be full and put that bolt back in. It should have a fibre washer to help seal it.
Run engine upto temp and wait until rad fans kick in at least twice on/ off.
Temp gauge should read just over 90.
Job done.
Just remove the bottom rad hose and drain it away.
Usually some coolant stays in the heater matrix so you could Jack the rear of the car up to assist removing it but not really necessary.
Bleeding the system can be an issue but only if you do it wrong.
Turn heater control knob to fully hot.
Firstly make up a long pipe with a plastic insert into it that can connect to the 6 inch length of pipe that has a blanking bolt or Allen bolt inserted into it in the inlet manifold on the left hand side of the engine. Remove bolt and connect the long pipe into it.
That pipe should now be placed into a container you make up that screws or push fits into the swirl pot.
Fill the system from the swirl pot just behind the exhaust Y piece in front of the engine slowly until full via the container screwed into swirl pot so you have coolant higher than the inlet manifold on top of the engine.
Then open bleed valve in radiator until a constant flow comes out and nip it up again.
Start engine keeping coolant topped up in your container never letting it become empty ot you’ll draw air in.
Keep the made up smaller pipe submerged in that container.
Feel rad top hose gets warm which indicates stat has opened and Rev the engine to push water around, squeeze top hose which can help force any air out.
Watch the water circulate and any air in the inlet manifold should come out through the smaller pipe via bubbles into the container and when only coolant comes through that pipe you have successfully bled the whole system.
Place bolt in smaller pipe and remove container in swirl pot. The swirl pot should be full and put that bolt back in. It should have a fibre washer to help seal it.
Run engine upto temp and wait until rad fans kick in at least twice on/ off.
Temp gauge should read just over 90.
Job done.
BritishTvr450 said:
No it’s easy.
Just remove the bottom rad hose and drain it away.
Usually some coolant stays in the heater matrix so you could Jack the rear of the car up to assist removing it but not really necessary.
Bleeding the system can be an issue but only if you do it wrong.
Turn heater control knob to fully hot.
Firstly make up a long pipe with a plastic insert into it that can connect to the 6 inch length of pipe that has a blanking bolt or Allen bolt inserted into it in the inlet manifold on the left hand side of the engine. Remove bolt and connect the long pipe into it.
That pipe should now be placed into a container you make up that screws or push fits into the swirl pot.
Fill the system from the swirl pot just behind the exhaust Y piece in front of the engine slowly until full via the container screwed into swirl pot so you have coolant higher than the inlet manifold on top of the engine.
Then open bleed valve in radiator until a constant flow comes out and nip it up again.
Start engine keeping coolant topped up in your container never letting it become empty ot you’ll draw air in.
Keep the made up smaller pipe submerged in that container.
Feel rad top hose gets warm which indicates stat has opened and Rev the engine to push water around, squeeze top hose which can help force any air out.
Watch the water circulate and any air in the inlet manifold should come out through the smaller pipe via bubbles into the container and when only coolant comes through that pipe you have successfully bled the whole system.
Place bolt in smaller pipe and remove container in swirl pot. The swirl pot should be full and put that bolt back in. It should have a fibre washer to help seal it.
Run engine upto temp and wait until rad fans kick in at least twice on/ off.
Temp gauge should read just over 90.
Job done.
Brilliant thank you, i'll change the thermostat too i think, I recon its failed as the car temp was rising more than it should yesterday, so may as well change is as a startJust remove the bottom rad hose and drain it away.
Usually some coolant stays in the heater matrix so you could Jack the rear of the car up to assist removing it but not really necessary.
Bleeding the system can be an issue but only if you do it wrong.
Turn heater control knob to fully hot.
Firstly make up a long pipe with a plastic insert into it that can connect to the 6 inch length of pipe that has a blanking bolt or Allen bolt inserted into it in the inlet manifold on the left hand side of the engine. Remove bolt and connect the long pipe into it.
That pipe should now be placed into a container you make up that screws or push fits into the swirl pot.
Fill the system from the swirl pot just behind the exhaust Y piece in front of the engine slowly until full via the container screwed into swirl pot so you have coolant higher than the inlet manifold on top of the engine.
Then open bleed valve in radiator until a constant flow comes out and nip it up again.
Start engine keeping coolant topped up in your container never letting it become empty ot you’ll draw air in.
Keep the made up smaller pipe submerged in that container.
Feel rad top hose gets warm which indicates stat has opened and Rev the engine to push water around, squeeze top hose which can help force any air out.
Watch the water circulate and any air in the inlet manifold should come out through the smaller pipe via bubbles into the container and when only coolant comes through that pipe you have successfully bled the whole system.
Place bolt in smaller pipe and remove container in swirl pot. The swirl pot should be full and put that bolt back in. It should have a fibre washer to help seal it.
Run engine upto temp and wait until rad fans kick in at least twice on/ off.
Temp gauge should read just over 90.
Job done.
Andy70 said:
Brilliant thank you, i'll change the thermostat too i think, I recon its failed as the car temp was rising more than it should yesterday, so may as well change is as a start
If both top and bottom rad hoses get warm the thermostat is opening but it’s never a bad idea to replace it. Usually you’d use one with a small hole in it to allow a small amount of water to circulate even from cold.
Don’t ask me why though. Maybe someone else can answer that question.
BritishTvr450 said:
Andy70 said:
Brilliant thank you, i'll change the thermostat too i think, I recon its failed as the car temp was rising more than it should yesterday, so may as well change is as a start
If both top and bottom rad hoses get warm the thermostat is opening but it’s never a bad idea to replace it. Usually you’d use one with a small hole in it to allow a small amount of water to circulate even from cold.
Don’t ask me why though. Maybe someone else can answer that question.
The hole allows a small amount of circulation of warm water to reduce 'thermal shock' when thermostat opens as well as allowing air bubbles trapped in the system to pass.
Thermostats are generally 82 degrees, lower than on some other RV8 applications, so don't assume all thermostats for RV8s are the same, as some suppliers do.
Re the fans, some cars are set up such that the individual fans are set to activate at different temperatures and various kits have been available over the years to allow that, so just one fan coming on might not necessarily indicate a problem. It's not related to your questions but some owners, me included, have wired-in a manual override switch for the fans, though I haven't heard much, if any, mention of that for years.
In the back of my mind I seem to recall that some TVR thermostats had a bigger 'hole' than normal but I might be mixing that up with another car.
Thermostats are generally 82 degrees, lower than on some other RV8 applications, so don't assume all thermostats for RV8s are the same, as some suppliers do.
Re the fans, some cars are set up such that the individual fans are set to activate at different temperatures and various kits have been available over the years to allow that, so just one fan coming on might not necessarily indicate a problem. It's not related to your questions but some owners, me included, have wired-in a manual override switch for the fans, though I haven't heard much, if any, mention of that for years.
In the back of my mind I seem to recall that some TVR thermostats had a bigger 'hole' than normal but I might be mixing that up with another car.
Andy70 said:
oh yeah of course, why didn't i think of that, i was checking that on my other car too when i changed the coolant, I've also noticed only 1 fan is working as well, i think that's stopped since I've had the car
Just behind the back of the radiator sometimes slightly hidden under the rad itself should be two block connectors feeding each fan.Start by finding those and pull apart, clean terminals and re join. If only one fan comes on try connecting the wires from that fan to the other fan, it should fire up, if not suspect a wiring fault to that non working fan or the fan itself stuck or broken or the wires into the fan not making a good contact.
Try spinning the non working one with your fingers when cold. It might be seized or cream crackered.
Only then consider if it has some aftermarket change.
People generally only create a different operating temp for second fan to help when driving in cold weather which doesn’t make much sense as the fans wouldn’t come on anyway as the engines operating at a lower temp meaning neither fans will come on.
Edited by BritishTvr450 on Wednesday 31st July 11:15
Edited by BritishTvr450 on Wednesday 31st July 11:20
TarquinMX5 said:
The hole allows a small amount of circulation of warm water to reduce 'thermal shock' when thermostat opens as well as allowing air bubbles trapped in the system to pass.
Thermostats are generally 82 degrees, lower than on some other RV8 applications, so don't assume all thermostats for RV8s are the same, as some suppliers do.
Re the fans, some cars are set up such that the individual fans are set to activate at different temperatures and various kits have been available over the years to allow that, so just one fan coming on might not necessarily indicate a problem. It's not related to your questions but some owners, me included, have wired-in a manual override switch for the fans, though I haven't heard much, if any, mention of that for years.
In the back of my mind I seem to recall that some TVR thermostats had a bigger 'hole' than normal but I might be mixing that up with another car.
Out of interest why did you fit an override switch. Is it purely a precautionary measure incase the Otto switch fails. Thermostats are generally 82 degrees, lower than on some other RV8 applications, so don't assume all thermostats for RV8s are the same, as some suppliers do.
Re the fans, some cars are set up such that the individual fans are set to activate at different temperatures and various kits have been available over the years to allow that, so just one fan coming on might not necessarily indicate a problem. It's not related to your questions but some owners, me included, have wired-in a manual override switch for the fans, though I haven't heard much, if any, mention of that for years.
In the back of my mind I seem to recall that some TVR thermostats had a bigger 'hole' than normal but I might be mixing that up with another car.
My car no longer uses the Otto switch to turn fans on, it’s fitted with an MBE Ecu and uses the Ecu temp sender to switch fans on at 92 and off at 88. watching the temp readout on computer it appears very efficient at doing so.
Andy70 said:
Ok thanks again I'll check that out tomorrow, too hot today I think for rummaging under a car on the drive
If you wanna be the bestWanna beat the rest
Dedications what you need
To be a record breaker yeaaaah
I was working on mine all day yesterday before I nearly collapsed with heat stroke
BritishTvr450 said:
Andy70 said:
Ok thanks again I'll check that out tomorrow, too hot today I think for rummaging under a car on the drive
If you wanna be the bestWanna beat the rest
Dedications what you need
To be a record breaker yeaaaah
I was working on mine all day yesterday before I nearly collapsed with heat stroke
BritishTvr450 said:
Out of interest why did you fit an override switch. Is it purely a precautionary measure incase the Otto switch fails.
My car no longer uses the Otto switch to turn fans on, it’s fitted with an MBE Ecu and uses the Ecu temp sender to switch fans on at 92 and off at 88. watching the temp readout on computer it appears very efficient at doing so.
Simply to give me the option to switch on earlier if I wanted to, ie increase airflow in stationary traffic. I suppose it would cover a failed otter switch but that wasn't part of the thought process (I don't think). Always had them on Kenlowes back in the day and used them occasionally, so fitted one - it was a long time ago now, though. Having said that, none of my other cars have override switches fitted, I leave that to the modern systems and am quite reluctant now to fiddle with the new stuff, far too complex for me My car no longer uses the Otto switch to turn fans on, it’s fitted with an MBE Ecu and uses the Ecu temp sender to switch fans on at 92 and off at 88. watching the temp readout on computer it appears very efficient at doing so.
BritishTvr450 said:
Andy70 said:
oh yeah of course, why didn't i think of that, i was checking that on my other car too when i changed the coolant, I've also noticed only 1 fan is working as well, i think that's stopped since I've had the car
Just behind the back of the radiator sometimes slightly hidden under the rad itself should be two block connectors feeding each fan.Start by finding those and pull apart, clean terminals and re join. If only one fan comes on try connecting the wires from that fan to the other fan, it should fire up, if not suspect a wiring fault to that non working fan or the fan itself stuck or broken or the wires into the fan not making a good contact.
Try spinning the non working one with your fingers when cold. It might be seized or cream crackered.
Only then consider if it has some aftermarket change.
People generally only create a different operating temp for second fan to help when driving in cold weather which doesn’t make much sense as the fans wouldn’t come on anyway as the engines operating at a lower temp meaning neither fans will come on.
Edited by BritishTvr450 on Wednesday 31st July 11:15
Edited by BritishTvr450 on Wednesday 31st July 11:20
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