Hard bottom rad hose

  • Thread starter mynheers_a_pint
  • Start date
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mynheers_a_pint

Guest
ok this has me stumped and a little worried.

the new engine is fully run in and aside from a dodgy temp sensor, everything seems to work ok. I know the temp sensor is wrong as it will read halfway if the car is left in the sun without driving it!

However, this afternoon i drove home from work, not unlike any other day. I gave it a short burst of vigor on the motorway but that was all. The temp sensor did it's usual thing of reading normal from start then going to the top end of the gauge after 10-15 mins of driving. I got home and popped the bonnet as i regularly do to make sure things are ok and check the hoses just in case. Well the bottom hose was quite hard and this worried me a little. I had previously sat in the queue for Japfest a month ago for over an hour and while the gauge was reading hot, the fans were kicking in and the hoses were soft and never too hot to touch.

The cooling system was thoroughly bled and i have done it a couple of times before twigging that the sensor was borked. When i found this, i imediately thought it was a possible airlock so got to it and despite being hot bled it, only to find no trapped gasses. Next was the thermostat which i pulled out and threw in the kettle, only to find that too was functioning. I will replace it anyway as it doesn't seem to close properly but that's far from the issue. So i put it back together and finished by starting the car with the rad cap removed to fully bleed the system. My next concern was that i found a slow bubbling of the coolant. Just a bubble every 10 or so seconds but should i be worried about this? I'll try it again when it is cold but is there anything i should consider?? All the engine faces were flat when put together and i used an HKS 1.2mm gasket. Could it be a leak somewhere letting air into the system? I haven't really got time to investigate fully myself, so some direction would help!

Thanks... :doh:
 
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mynheers_a_pint

Guest
i'm going to the garage tomorrow to put a sniffer on it but that's my worst nightmare if that's gone.

I do hope it isn't a problem with the build...
 
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mynheers_a_pint

Guest
well the headgasket is fine and we seem to think we have solved the mystery. the more we ran it, the less gas was escaping meaning we can only assume it is a large air lock, probably caused by a dodgy rad cap and lack of water in the expansion bottle.
 

antgtir

New Member
Did you have the interior fans going and the temp set to hot whilst bleeding?

Cant fully remember but isnt there two thermostats on the R? Worth checking to ensure both are working if there is.

Sounds like there is either air in the system or something mechanical has failed i.e. thermostat.

Ant.
 

geoff pine

Well-Known Member
If the thermostat is opening as it should then the two rad hoses would be (around ! ) the same temperature and not soft .
 
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mynheers_a_pint

Guest
well from what i gather, with the rad cap being knackered and me not putting any water in the expansion bottle it inadvertantly syphons in air which gets trapped in the system but the thought about the heater matrix is a good one as i did do all of this with the fans off and set to cold. They're jsut so noisy!

I'll have a fiddle tonight.
 
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