'98 1.9 TDI blowing cold air
Currently, my audi is blowing cold air regardless of what setting it's on. I've traced this back to there being an airlock in the system, as the problem started on the journey home after checking my coolant level. I must of got some air trapped in there somehow, and now it's made its way to the heater matrix. The problem I have however, is how to remove this airlock.
In my old car, it was a simple case of removing the coolant cap from cold, starting the engine with heaters on full blast, and letting it bubble over until the needle hit 80 degrees. This worked for my old car, but I've heard stories that the 1.9 engine wont go to 90 degrees just from idling, so I guess this method wont work.
I'm a bit tight on money at the minute, so I need a quick cheap fix. I'm also taking the kids to scotland on the weekend, and driving without heaters wouldn't be ideal in the cold weather. Any ideas?
Re: '98 1.9 TDI blowing cold air
Re: '98 1.9 TDI blowing cold air
Quote:
Originally Posted by
Aeikostx
Currently, my audi is blowing cold air regardless of what setting it's on. I've traced this back to there being an airlock in the system, as the problem started on the journey home after checking my coolant level. I must of got some air trapped in there somehow, and now it's made its way to the heater matrix. The problem I have however, is how to remove this airlock.
In my old car, it was a simple case of removing the coolant cap from cold, starting the engine with heaters on full blast, and letting it bubble over until the needle hit 80 degrees. This worked for my old car, but I've heard stories that the 1.9 engine wont go to 90 degrees just from idling, so I guess this method wont work.
I'm a bit tight on money at the minute, so I need a quick cheap fix. I'm also taking the kids to scotland on the weekend, and driving without heaters wouldn't be ideal in the cold weather. Any ideas?
you would not have caused an airlock simply by checking the coolant
level.
the symptoms you indicate describe a head gasket fault,with combustion gasses getting into the cooling system and finding their way to the highest
part of the system unfortunately,
regards,
stewy.
Re: '98 1.9 TDI blowing cold air
I've already had it checked for a headgasket failure, and there doesn't seem to be any signs. It runs perfectly, with no loss of power, and the engine has never missed a beat. I think it's the airlock, as when I took the cap off I heard the cap "psss" as if the presure was releasing. After the journey back, when I checked the coolant again, there was no pressure build up, so I dont really know what to think.
Re: '98 1.9 TDI blowing cold air
Quote:
Originally Posted by
Aeikostx
I've already had it checked for a headgasket failure, and there doesn't seem to be any signs. It runs perfectly, with no loss of power, and the engine has never missed a beat. I think it's the airlock, as when I took the cap off I heard the cap "psss" as if the presure was releasing. After the journey back, when I checked the coolant again, there was no pressure build up, so I dont really know what to think.
i'm not trying to tell you "how to suck eggs", but any and all normal cars,with cooling systems working 100% correctly,will give off pressure when the cap is released.
the whole idea of having a "fancy" cap complete with spring is to pressurise the water/coolant,usually to somewhere between 7-14psi.
this raises the boiling point of water,which would normally boil at 100deg c.
to 115-120,or thereabouts.
this is something i have never been able to understand-people pulling up at service stations,raising the bonnet and removing the radiator cap "to let
the engine cool down"!!!
immeadiatley the cap is removed,the pressure drops from atmospheric+7-14, to atmospheric.
the coolant that was up until then pressurised and quite happy at 110degs
without boiling,is immeadiatley reduced to atmospheric pressure and boils over within seconds because at atmospheric it boils at 100degs.
i still think your symptoms are the early stages of head gasket failure,and while the car is running you may even experience "better performance" from time to time,as believe it or not,a bit of coolant,or water introduced
into the cylinder works wonders at times!!
best regards,take care,
stewy.
