hi to all i have recently got a 02 tdi elegance just had a new pump and belt fitted the problem is with the cooling system

temp gets to 90 after 20 minuets and will stay there even on the motorway i had some issues with the heater but seam ok for now

after 20 to 30 minuets the top hose on the rad is hot and the bottom hose is stone cold

also the radiator is stone cold from top to bottom the only hot part is at the top hose connection

despite this the car shows no sign of overheating

i think the radiator is at fault

any body had the same with there Octavia or any other things i should be looking at before buying a new rad

thanks from john

The warm-up seems way too slow to me, which usuallys suggest an open or missing thermostat; mine only takes about 5 miles/10 minutes even in the dead of last Winter with air temps down to -10C.

Are the radiator hoses hard when the top hose is hot?

Is either fan running, with the engine hot, and the Climatronic in "Auto" mode?

hope its not like mine,

http://briskoda.net/forums/topic/153339-alh-tdi-prob/page__p__1903542entry1903542

I would agree, about 10 mins/5miles of fair gentle town driving in the morning gets mine up to the normal 90 deg C

I would suggest maybe a massive airlock somewhere, but not quite sure where.

The warm-up seems way too slow to me, which usuallys suggest an open or missing thermostat; mine only takes about 5 miles/10 minutes even in the dead of last Winter with air temps down to -10C.

Are the radiator hoses hard when the top hose is hot?

Is either fan running, with the engine hot, and the Climatronic in "Auto" mode?

the hoses are hard all top hoses are warm/hot just the bottom and rad are cold

neither of the fans run when in auto and the front rad the air con ran is cold but thats what i would expect in this weather as its not cooling the inside of the car

i will try the thermostat first as this could have failed closed and is not allowing the flow from the rad

thanks from john

If both main hoses are hard, then the system is pressurising correctly when the engine is hot, which strongly suggests to me that either the fans are both running at all times or the thermostat has been removed.

Since you say the fans aren't running, check that there actually is a thermostat! If there is, test that it works, and isn't just stuck open.

If both main hoses are hard, then the system is pressurising correctly when the engine is hot, which strongly suggests to me that either the fans are both running at all times or the thermostat has been removed.

Since you say the fans aren't running, check that there actually is a thermostat! If there is, test that it works, and isn't just stuck open.

i am looking it to the stat but if was stuck open or missing then there would be some flow around the system and the rad / bottom pipe would be warm

the fans will not come on if the sensor is on the rad because it is cold

strange that this car has not overheated yet as it was a taxi and did around 200 miles a day with this problem for months until the pump went (i should have got the stat done when they did the pump and belt )

thanks from john

You might think that, but the physical fact of there being a thermostat in the system but stuck open regulates the peak coolant flow, so you can finish up over-cooling if you take the stat out.

You might think that, but the physical fact of there being a thermostat in the system but stuck open regulates the peak coolant flow, so you can finish up over-cooling if you take the stat out.

hi i have replaced the stat (a five minuet job) and now getting full circulation of the coolant all pipes are hot i will find out today if it comes up to temp any quicker

i haven't had chance to test the old one yet but there was a piece of plastic from the stat housing that had broken off came out when i took the housing off

when i was doing the job i uncovered another pipe (from the bottom of the expansion tank into a plastic pipe on the block) when i moved it it lost coolant and pressure so i have to repair that will do that today

thanks for all your input

john