sparcost3
Member
Registered: 21st Sep 09
Location: Stafford, Staffordshire
User status: Offline
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hi everyone, sorry its not corsa related.. but i was wondering if anyone can shed any light on my problem with my audi a4 estate daily.
the problem is that the car is overheating due to the flow in the coolent system not being right.
there is no return flow to the header tank and the top coolent hoses are hot but the bottom ones are cold showing there is no circulation.
i have replaced the waterpump,
i have changed the thermostat for a brand new 1
i changed the temprature sensor (CTS) and still no joy
[Edited on 21-01-2015 by sparcost3]
[Edited on 22-01-2015 by sparcost3]
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carl roper
Member
Registered: 17th May 09
Location: Newport Shropshire
User status: Offline
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Is the radiator blocked? Doesn't sound likenit flowing through it anyway
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richardworrall
Premium Member
Registered: 20th Sep 05
Location: Derby
User status: Offline
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can you disconnect a top pipe and blow the water through the system or hear air escaping as you do it?
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Steve
Premium Member
Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
User status: Offline
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have you bled it properly?
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IvIarkgraham
Premium Member
Registered: 27th Mar 04
Location: Ellesmere Port, Cheshire
User status: Offline
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are you losing coolant?
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SteveoBC
Premium Member
Registered: 22nd Feb 07
Location: Bucks
User status: Offline
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quote: Originally posted by Steve
have you bled it properly?
i was going to say water pump first as my dads one went (plastic impeller broke off so no pressure)
but im going to think the same as the other steve here
Must have an airblock in the system somewhere
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Steve
Premium Member
Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
User status: Offline
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The problem is until the stat gets hot enough it can stop the water getting into the radiator side of the system, but because there is no water round the back of the thermostat because of air it doesn't get hot enough, leading to catch 22.
Usually there are plastic bleed screws in various parts of the system too, but sometimes filling up with boiling water can help as it will open the stat up.
Also make sure heater is on hot.
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ShEp
Member
Registered: 9th Aug 05
Location: Dingwall, Highland
User status: Offline
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Run it for 45mins with the header tank cap off and the heaters on full blast.
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Steve
Premium Member
Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
User status: Offline
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And rev it too find that helps force out locks
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pow
Premium Member
Registered: 11th Sep 06
Location: Hazlemere, Buckinghamshire
User status: Offline
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And Jack the nose up in the air, have to do that to older 6 cylinder bmws
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Brett
Premium Member
Registered: 16th Dec 02
Location: Manchester
User status: Offline
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and cross your fingers
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_Allan_
Member
Registered: 24th Mar 04
User status: Offline
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Ensure the rear seats are folded flat.
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GB123
Premium Member
Registered: 21st Nov 11
Location: Kent
User status: Offline
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Check the door hinges
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sparcost3
Member
Registered: 21st Sep 09
Location: Stafford, Staffordshire
User status: Offline
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Cheers for the replies lads I will try this todau
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baza31
Member
Registered: 19th Apr 03
Location: yorkshire
User status: Offline
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sparcost3
Member
Registered: 21st Sep 09
Location: Stafford, Staffordshire
User status: Offline
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quote: Originally posted by carl roper
Is the radiator blocked? Doesn't sound likenit flowing through it anyway
yep think so carl need to remove bumper to get it off not like on a corsa so maybe at the weekend or a weekend when its not -5.....
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carl roper
Member
Registered: 17th May 09
Location: Newport Shropshire
User status: Offline
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Take the pipes off and run a hose through it to check?
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Mattb
Member
Registered: 2nd Feb 03
Location: Under your sisters bed
User status: Offline
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Really does sound like you have an airlock. Take the plastic trim of the plenum chamber (the big mofo over the battery etc) there are two hoses that go into the heater matrix around the center of the bulkhead, one of these has a hole in. With the engine running, Loosen the spring clamp and pull the hose back, but not off so the hole is past the pipe for the matrix. This will bleed any air out the matrix. This is extremely common when the coolant system hasn't been vacuum bled.
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sparcost3
Member
Registered: 21st Sep 09
Location: Stafford, Staffordshire
User status: Offline
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quote: Originally posted by carl roper
Take the pipes off and run a hose through it to check?
did that yesterday, runs through totally fine.
drove to work and felt the radiator after a 20 mile drive and the whole thing was stone cold...... top pipe hot and bottom pipe cold. that bottom pipe conects directly to the thermostat and even though ive replaced it it cant be working??
is it ok to remove it altogether and see if i get flow through the system without a thermostat?
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sparcost3
Member
Registered: 21st Sep 09
Location: Stafford, Staffordshire
User status: Offline
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quote: Originally posted by Mattb
Really does sound like you have an airlock. Take the plastic trim of the plenum chamber (the big mofo over the battery etc) there are two hoses that go into the heater matrix around the center of the bulkhead, one of these has a hole in. With the engine running, Loosen the spring clamp and pull the hose back, but not off so the hole is past the pipe for the matrix. This will bleed any air out the matrix. This is extremely common when the coolant system hasn't been vacuum bled.
whats a plenum chamber ? i removed those 2 pipes next to the battery and proved there is flow through the matrix when conecting to a hose. however.... there seemed to be no flow coming out of those 2 hoses into the matrix even when revving engine?
very strange
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sparcost3
Member
Registered: 21st Sep 09
Location: Stafford, Staffordshire
User status: Offline
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quote: Originally posted by IvIarkgraham
are you losing coolant?
no i am not loosing any coolent
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sparcost3
Member
Registered: 21st Sep 09
Location: Stafford, Staffordshire
User status: Offline
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quote: Originally posted by Steve
The problem is until the stat gets hot enough it can stop the water getting into the radiator side of the system, but because there is no water round the back of the thermostat because of air it doesn't get hot enough, leading to catch 22.
Usually there are plastic bleed screws in various parts of the system too, but sometimes filling up with boiling water can help as it will open the stat up.
Also make sure heater is on hot.
that pipe was full of air, after testing flow through the radiator i filled it up with kettle water and ran it but it was still clod althogh now feels pressured. im thinking even though the thermostat is brand new, would it be worth removing all together to see if the radiator then gets flow?
there is still no water returning to header tank even with a brand new waterpump
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sparcost3
Member
Registered: 21st Sep 09
Location: Stafford, Staffordshire
User status: Offline
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yesterday i had no flow through the system (no return to header tank) and the radiator and bottom hose stone cold.
the temprature gauge went to about 70 after 10 mins of driving and the heating was working to some degree but the engine was very hot with the coolent not circulating properly.
i also noticed that when i used the screen wash wipers the heater blowers became more powerfull (had more blow power)
today i removed the thermostat alltogether. i now have perfect strong flow to my return on the header tank, and the radiator and all hoses warm up and pressurise now but are only warm not hot.?
i now have no warmth whatsoever coming through my heating. i dont understand the problem.. it dosent make sence!! can anyone shed any light??
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