Audi a4 2006 losing coolant

jack hackett

Hi, audi a4 1.9 diesel 2006, the coolant light came on about a week ago, filled the tank to the max, then a couple of days later its down to the min level and ever since ive been topping it up every 2 days, the oil is black so doesnt seem to be leaking in there, any ideas what the issue would be? presumably i shouldnt leave this too long? would there potentially just be a leak at the bottom of the tank itself?

jack hackett

anybody?

porsche boy

Are you seeing puddles of water or coolant under the car?
Check the passanger side floor also, might have a leak in the heater matrix

jack hackett

porsche boy wrote: »

Are you seeing puddles of water or coolant under the car?
Check the passanger side floor also, might have a leak in the heater matrix

Thanks for coming back to me, nothing under the car but i think i see a wet patch on metal directly under the coolant tank, its hard to tell though with these wet/frosty mornings

lchhung

The system of the cooling is relatively simple. So, if you don't see any white color from exhaust while driving (a sign of head gasket failed) and I hope this is not, then it would leak somewhere. Please check crack on, hoses, worn clips, bolts, or crack. Myself got an experience with this because I did not tight the bolt at the thermostat when I changed coolant ^^. Update us if you find something.

jack hackett

lchhung wrote: »

The system of the cooling is relatively simple. So, if you don't see any white color from exhaust while driving (a sign of head gasket failed) and I hope this is not, then it would leak somewhere. Please check crack on, hoses, worn clips, bolts, or crack. Myself got an experience with this because I did not tight the bolt at the thermostat when I changed coolant ^^. Update us if you find something.

Cheers, no white smoke so it must be a leak, i will get a mechanic to check it out

lchhung

jack hackett wrote: »

Cheers, no white smoke so it must be a leak, i will get a mechanic to check it out

Yip, no white smoke is perfect. I would park the car for a few hours on a clean and flat surface, and place some newspapers under the engine to see if is there any water doped down, and if coolant level is down as well. Hope fully no issue with engine block and radiator. If failed on hoses, it would be simple to fix by yourself to save $$.

If the coolant level is relatively remained, I would focus on crack on the hoses out from the pump first, down to the radiator bottom, and go back up to the engine block. Because, when engine is hot, pump run and thermostat open will circulate the water with high pressure resulting in leaking. Heat from engine will clean out water so difficult to confirm with hot engine.

A mechanic could use his cooling system test kit to check the leak by pressurise air inside the cooling to see bubbles and lost of pressure.

Good luck and update us your issue.

jack hackett

lchhung wrote: »

Yip, no white smoke is perfect. I would park the car for a few hours on a clean and flat surface, and place some newspapers under the engine to see if is there any water doped down, and if coolant level is down as well. Hope fully no issue with engine block and radiator. If failed on hoses, it would be simple to fix by yourself to save $$.

If the coolant level is relatively remained, I would focus on crack on the hoses out from the pump first, down to the radiator bottom, and go back up to the engine block. Because, when engine is hot, pump run and thermostat open will circulate the water with high pressure resulting in leaking. Heat from engine will clean out water so difficult to confirm with hot engine.

A mechanic could use his cooling system test kit to check the leak by pressurise air inside the cooling to see bubbles and lost of pressure.

Good luck and update us your issue.

Thanks mate, i will do this as you say, i can see that the level continues to drop when the car is sitting there over nigth so if i put paper under the car i will be able to see if it drops on it

jca

jack hackett wrote: »

Thanks mate, i will do this as you say, i can see that the level continues to drop when the car is sitting there over nigth so if i put paper under the car i will be able to see if it drops on it

That won't work as the undertray will catch any leaks.

SwD

Its probably the water pump. I'd say if they're doing that job get them to do the timing belt while they're at it. Not cheap but if it's losing coolant that would be my guess.

jack hackett

SwD wrote: »

Its probably the water pump. I'd say if they're doing that job get them to do the timing belt while they're at it. Not cheap but if it's losing coolant that would be my guess.

The timing belt was done only recently, is the water pump a big job?

SwD

jack hackett wrote: »

The timing belt was done only recently, is the water pump a big job?

It depends on the car I think, but for my car I had to have the whole engine removed as water pump was impossible to get at otherwise. I was told to have timing belt done while I was at it. Ultimately its a labour cost. The parts are cheap.

Tropheus

My experience has been that hoses generally fail pretty quickly and you get fairly rapid loss of coolant. More subtle loss is generally seeping out of the water pump. Only solution is a new water pump and do the timing belt at the same time. Make sure you get a genuine Audi water pump. I've had bad experiences with spurious brands.