ok heres the situation be prepared for a long story lol


i bought the wife a 01 a4 1.8 turbo lovely little car she wanted 1 for a while found a nice clean example with just over 100k on it ,when we got it the heater sucked the dealer said it was a common prob it just needed a thermostat ,so i got it home drove it for a while no problems i noticed it had a lil coolant leak from the back of the head i thought head gasket ,started checking it out and it was a plastic pipe on the back of the head no worries changed it and thermostat heater was ok not briliant then 1 day it got warm and the coolant was sludgy and brown like it was mixing with oil so i thought head gasket .pulled the head had it cracktested and skimmed put it all back together same thing ,then i found out about the oil cooler problems i replaced that and no more mixing problems .the wife drove the car for about 2 weeks and it started to get hot and bubble water out of the coolant tank ,oh and it started running on 3 cylinders ,so i ripped the motor apart again new head gasket ,thermostat timing belt water pump tensioner and a coolant bottle put it back together car ran fine heater was good ,again the wife drove it for about 2 weeks and the coolant bottle split along the seam ,put a new coolant bottle on there and cant get it to bleed up ,it will idle fine for and hour or so temp just fine and heat i can run it at 2500 3000 in the shop fine ,i drive it 1-2 miles and the temp gauge goes up and the coolant pours out of the coolant bottle ,it makes a funny noise aswell like cold water is mixing with hot .i replaced the thermostat again ,bleed the system thro the lil hole in the heater hose lifted the coolant bottle etc and again its fine when its not moving but as soon as you drive it ,it gets hot and pumps the coolant out ,it seems to me that the coolant isnt circulating correctly i back flushed the rad and heater core along with the motor etc i even tried jacking the front of the car up etc to get all the air out ,ive never had problems with cooling systems like this dam car im on my last nerve with it so if any1 has any ideas let me know as it looks kinda sad parked up the top of the yard lol


thanks in advance and sorry for the long post

 

i have never seen this issue before they are plenty of people with heating issues but thats due to clogged heater cores and sludge

 

i cant work it out ive spent way to many hours messing with it ,i just dont understand why its fine until you drive it im sure its something simple ive overlooked

 

somthing simple as always a stupid mistake a unpluged wire or somthing what coolent are u using in the car it should be pink and can only be bought at the dealer

 

nobody got any ideas then

 

oil cooler probably

 

Idle the car with the expansion tanks cap off and the heat on full blast for about 10 minutes. I bet it fixes your problem.

 

its been replaced im not geting oil in the coolant ,the coolant wont stay in the coolant tank when yuou drive it but its fine when it idles or when its reved or held at any rpm

 

Did you try this yet?

 

yep tried that its fine when its stationary drive it 1-2miles and its getting hot and pumping the coolant out heaters hot and everything