Water temps high when heater on!?
Discussion
Hi all
I'm delighted to have joined caterham
Ownership and have a lovely little 1.6 K roadsport that is an absolute delight.
One full track day under its belt and by the end of the day we were one of the quickest things out there, confidence inspiring!
However....
I notice that if I pull the lever to open the heater matrix, my water temperature reports that it's at 100 degrees all the time. Never goes up or down.
Close the valve and temps come down
And are reported correctly.
Is this normal behaviour?
Any advice appreciated
I'm delighted to have joined caterham
Ownership and have a lovely little 1.6 K roadsport that is an absolute delight.
One full track day under its belt and by the end of the day we were one of the quickest things out there, confidence inspiring!
However....
I notice that if I pull the lever to open the heater matrix, my water temperature reports that it's at 100 degrees all the time. Never goes up or down.
Close the valve and temps come down
And are reported correctly.
Is this normal behaviour?
Any advice appreciated
shrink1061 said:
Hi all
I'm delighted to have joined caterham
Ownership and have a lovely little 1.6 K roadsport that is an absolute delight.
One full track day under its belt and by the end of the day we were one of the quickest things out there, confidence inspiring!
However....
I notice that if I pull the lever to open the heater matrix, my water temperature reports that it's at 100 degrees all the time. Never goes up or down.
Close the valve and temps come down
And are reported correctly.
Is this normal behaviour?
Any advice appreciated
Wow first ever post, and it's one here re your Caterham!I'm delighted to have joined caterham
Ownership and have a lovely little 1.6 K roadsport that is an absolute delight.
One full track day under its belt and by the end of the day we were one of the quickest things out there, confidence inspiring!
However....
I notice that if I pull the lever to open the heater matrix, my water temperature reports that it's at 100 degrees all the time. Never goes up or down.
Close the valve and temps come down
And are reported correctly.
Is this normal behaviour?
Any advice appreciated
Welcome to Pistonheads and of course to Caterham ownership too.,
It's worth checking to see if the gauge is working properly first, followed by the sender.
You need to disconnect the sender cable and earth it, so see if it goes from zero to full deflection once earthed, IE from cold to hot on the gauge.
If that is all good it could be the sender.
It's also worth checking to see if you have an air lock, which is common on k series, but if it is running ok and not overheating, I can't see it being that.
Another thing to check is the thermostat , but check the easier bits first.
I assume the car is running ok, and no water leaks?
When the heater is turned on, does hot air come out of the vents?
Feel all the hoses from the engine up to the heater when the car is hot, and make sure all are warm ( or very hot be careful!)
I hope that helps as a starter for 10!
Good luck,
Thanks for coming back to me!
Yep heater works a treat, all pipes warm.
As above if I push the lever for heater in my temps read normal (80 ish degrees) and the dial goes from cold to hot as the engine increases in temp.
But open the heater valve and all of a sudden temps rise to 100 and then stay there rock solid.
One full track day and temps didn't waver or go above that. Just very odd
Yep heater works a treat, all pipes warm.
As above if I push the lever for heater in my temps read normal (80 ish degrees) and the dial goes from cold to hot as the engine increases in temp.
But open the heater valve and all of a sudden temps rise to 100 and then stay there rock solid.
One full track day and temps didn't waver or go above that. Just very odd
also worth noting that even when it reads 100 degrees, the front radiator only feels reasonably warm, and the fan isn't kicking in. So it's not like I think the engine is actually getting too hot.
as soon as i close the heater valve, the temps fall back down to 80 degrees within a few minutes.
odd!
as soon as i close the heater valve, the temps fall back down to 80 degrees within a few minutes.
odd!
Sounds like an air lock. The heater matrix is the high point in the system, therefore the likely place for air to collect and prevent/restrict coolant flow around the bypass.
I always fill the engine with coolant from this high point and have never experienced the problems other K-series owners constantly complain about.
I disconnect the highest bypass hose from the heater valve, then attach an old 90 degree bend to the heater valve. I now have two open ends of pipe pointing upward.
With the radiator bleed plug and expansion tank cap removed I fill with coolant from one of these open ends (I don’t think it matters which – have alternated on one occasion).
The plug is replaced when coolant appears at the bleed plug hole and the cap is put back on when the coolant reaches the required level in the expansion tank.
Unfortunately, once coolant appears in both ends of the open pipework things get complicated and occasionally messy.
I can’t explain the last step of removing the temporary bend and reconnecting the bypass to the heater valve (without letting air in) - it’s one of those things I have to reinvent every time I do the job - it's useful at this point to have 3 hands!.
I know it’s not easy, but as I said earlier it works.
I always fill the engine with coolant from this high point and have never experienced the problems other K-series owners constantly complain about.
I disconnect the highest bypass hose from the heater valve, then attach an old 90 degree bend to the heater valve. I now have two open ends of pipe pointing upward.
With the radiator bleed plug and expansion tank cap removed I fill with coolant from one of these open ends (I don’t think it matters which – have alternated on one occasion).
The plug is replaced when coolant appears at the bleed plug hole and the cap is put back on when the coolant reaches the required level in the expansion tank.
Unfortunately, once coolant appears in both ends of the open pipework things get complicated and occasionally messy.
I can’t explain the last step of removing the temporary bend and reconnecting the bypass to the heater valve (without letting air in) - it’s one of those things I have to reinvent every time I do the job - it's useful at this point to have 3 hands!.
I know it’s not easy, but as I said earlier it works.
I think I get you!
So unplug top Hose from heater valve and attach something to it which gives it an upward facing fill point.
Then with bleed cap and expansion tank top off, fill one or both the open hoses with cool and until it comes out bleed valve.
Seal up bleed valve and make sure level is right in expansion tank.
Then try not to make a total mess plugging the hose back into the valve?
So unplug top Hose from heater valve and attach something to it which gives it an upward facing fill point.
Then with bleed cap and expansion tank top off, fill one or both the open hoses with cool and until it comes out bleed valve.
Seal up bleed valve and make sure level is right in expansion tank.
Then try not to make a total mess plugging the hose back into the valve?
So to further this!
Last night I took it out and got it up to temp.
-radiator top hose hot
-both sides of heater pipe work hot (don't think heater has air lock)
-when radiator bleed opened, coolant comes out.
-bottom hose on radiator only mildly warm.
-return path on cooling system back into block only moderately warm.
Could it still be a problem at radiator? It seems that everything is fine until this point. The return path is never hot enough for thermostat to open. Something is stopping the hot water getting from top
Of radiator back out.
However when squeezed, all hoses cause movement in expansion tank including the bottom radiator!
Stumped!
Last night I took it out and got it up to temp.
-radiator top hose hot
-both sides of heater pipe work hot (don't think heater has air lock)
-when radiator bleed opened, coolant comes out.
-bottom hose on radiator only mildly warm.
-return path on cooling system back into block only moderately warm.
Could it still be a problem at radiator? It seems that everything is fine until this point. The return path is never hot enough for thermostat to open. Something is stopping the hot water getting from top
Of radiator back out.
However when squeezed, all hoses cause movement in expansion tank including the bottom radiator!
Stumped!
Still an airlock. (Although is the thermostat definitely ok?)
Jack up the front as high as possible - massage the pipes as much as possible and open the bleed on the top of the rad.
When I was doing mine a while ago we also put (more) pressure into the expansion tank too.
Eventually there was a gulgling and it cleared.
Jack up the front as high as possible - massage the pipes as much as possible and open the bleed on the top of the rad.
When I was doing mine a while ago we also put (more) pressure into the expansion tank too.
Eventually there was a gulgling and it cleared.
Interestingly everyone keeps talking about a bleed on top of the rad! I don't have one... what i have is:
the only thing that looks like a bleed, is the 4 inch rubber hose that comes out between the electric switch and the large rubber inlet hose.
Should I be bleeding from there?
best pipes to massage to get it all clear?
the only thing that looks like a bleed, is the 4 inch rubber hose that comes out between the electric switch and the large rubber inlet hose.
Should I be bleeding from there?
best pipes to massage to get it all clear?
The radiator in your photograph is different to that in my 98 car. It looks plastic whereas mine is steel and has a bleed point just to the right of the inlet hose.
The old radiators don’t have the smaller diameter pipe between the inlet and the fan switch. To what is this pipe connected (I can’t tell from your photograph)?
The old radiators don’t have the smaller diameter pipe between the inlet and the fan switch. To what is this pipe connected (I can’t tell from your photograph)?
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