A3 1.9 TDI drinks engine coolant

[sillydior]

i have a 1998 A3 1.9 TDI sport, i have had a few issues with it, like it takes its time to start when the engines warm, the glow plug light will not stop flashing when driving which i do not know the cause? i had the glowplugs replaced and it still flashes.
but my main problem is that the fact that the engine coolant needs topped up every several hundred miles, my concern is that the cylinder head gasket has a problem....
but there is no mayo on the oil cap, no oil in the coolant tank, no steam coming out of the exhaust, and the oil is a jet black colour, there is some small bubbles on the dip stick when i pull it out those.
where would all this coolant be going? when i open the coolant tank the release of the cap shows there is still good pressure in it.
and the last time i filled up the coolant after driving for a bit i could smell the coolant slightly for a bit while inside the car. those mines does not have air conditioning,
any help or advice knowledge on any of my problems would be much help thanks!!!

[kenney]

The glow plug light flashing is telling you there is a fault with the engine management,you need to have a fault code read.One reason for it to flash,is if the brake lights are not working,due to a faulty brake light switch,so check the brake lights first. Regarding the coolant loss,you will need to pressure test the coolant system,the fact that you smell the antifreeze,suggests the heater matrix is leaking.

[sillydior]

in the manual the flashing glowplug means that it goes into reduced power mode?
one of the rear fog lights is not working would that cause it to flash?
the smell of the engine coolant inside the car is not very often, just now and again.
a heater matrix problem? would that account for all the engine coolant i put into it? and where would i look to spot any problem?

[kenney]

A non working fog light will not activate the control light.Usually when the matrix leaks,you get a sweet kind of smell,in the vehicle,when you use the heater.,The leak could be anywhere,so you need to get the system pressure tested,if you can not see any obvious leaks

[sillydior]

i will get the pressure test done, but to anyones knowledge is problem common in my audi model?
its just i've read some horror stories on here about other peoples cylinder heads and gaskets and stuff and i'am paranoid about my motor.

[kenney]

Usually when the head gasket leaks, there is an over pressure in the coolant system and the engine will start to overheat,or signs of coolant in the oil.The radiator leaking is a fairly common fault

[sillydior]

okay i will get onto that thanks for your advice, there is not a high amount of pressure when i release the coolant cap, but that is half a litre of coolant i need to put in every 500 hundred miles or so...
the only signs that coolant could be going into the engine oil is there is a small amount of steam when i remove the oil cap after i've driven it for a while! does hot oil give off steam?
and there are little small bubbles on the dipstick would water cause this?

[kenney]

I think you mean fumes,oil does not steam,the small bubbles i would imagine are air bubbles.The coolant will mix with the oil to a certain extent,and the oil becomes greyish.

[jt77]

also check the water pump, will be cheaper than the head gasket.

[sillydior]

how do you check if the water pump is working?
is there any signs if that has a problem?

[jt77]

to check the water pump you need someone to help, first remove the small pipe from the top of the expansion tank. coolant should cycle backinto the expansion tank through this. start the engine with the pipe now pointing into the filler cap hole (so it doesn't go everywhere.) when you start the engine you should get a slow tricle of fluid from the little pipe. if you then put your foot on the accellarator the flow should increase as the water pump is driven by the timing belt. if it increases your pump should be fine, if not its a place to start.

if you're going to get the pump changed you might aswell get the cam belt and pulleys done too.

but before you do that get a garage to pressure test the system, and check for exhaust fumes in the coolant ( you can buy a "universal block tester kit" to do this) its a simple test, if there are traces there then you have a leak in the system somewhere which could point at either head gasket or a cracked block.

and if there is this you might aswell bite the bullet and get the head gasket changed at the same time.

you can also look for signs of coolant leak, (there usually a white residue if present)

i'm just about to have the head gasket done on mine now, having had the thermostat, water pump, cam belt all replaced. also flushed the system numerous times and checked the radiator for leaks or blockages. fingers crossed thats it cos i'm running out of options.

best of luck