Why do I have to keep topping up my coolant?

[Jamie TDI140]

As above...

Ive had the car (2.0 tdi BKD) since about Feb/March this year and ive had the coolant light come up about 3 times now due to low level. Now I've experienced this kind of thing on my old golf, but that was due to a poor seal on the block. I haven't done too much investigating as of yet as it seems to be every couple of months or so, but I just wanted to know if diesels tend to use more than petrols? (this is my first diesel car) or it's something that needs looking at.

Jamie.

 

[lfcrule1972]

I have no experience of Audi diesels - I previously owned a Citreon DS3 and an Astra that were both diesels and neither ever required top ups of the coolant.

How much are you topping up each time ? If it were me I'd get it looked at - is it still under warranty ?

 

[SootySport]

Assuming you have a good look around under the bonnet and under the car and can't see any obvious leaks, then the favourite and unfortunately costly common problems are----------

Cylinder head porous.
Head gasket gone.
EGR cooler leaking inside.

Plenty of these examples are on the A3 threads.

 

[Jamie TDI140]

I have no experience of Audi diesels - I previously owned a Citreon DS3 and an Astra that were both diesels and neither ever required top ups of the coolant.

How much are you topping up each time ? If it were me I'd get it looked at - is it still under warranty ?

Ive been topping it up when the warning comes up on the DIS, so below the minimum level and top it up to the max level. thinking about it I will definitely get it looked at, and I highly doubt im covered by any sort of warranty it once had, it's a 53 plate

Assuming you have a good look around under the bonnet and under the car and can't see any obvious leaks, then the favourite and unfortunately costly common problems are----------

Cylinder head porous.
Head gasket gone.
EGR cooler leaking inside.

Plenty of these examples are on the A3 threads.

I've had a little gander round the bay, and there is nothing showing on the floor, no matter where I park (ive recently come back from a trip to devon and was parking on massive incline hills) and it's always on a flat drive at home and nothing shows.

none of those above sound too enticing to be honest. I'll get it booked in and checked over.

I've noticed a bit of trend with all of the cars ive bought.... theyre always lemons haha

 

[Nessy]

If you have a good search on the A3 8P forum there are loads of similar cases as yours....
The early 2.0 tdi engines suffered from porous cylinder heads, so much so that VW/Audi revised the cylinder heads 3 times, until about 2006 at the revision C head they finally seemed to have solved the problem.
That's not to say that every early engine with an A or B head will leak, many don't, but the earlier models were much more susceptible to head problems than the later ones.
If you pull off the engine cover and look where the 2 metal pipes that carry fuel along the cylinder head are you should be able to make out the part number of the cylinder head cast into it.
It will end in either an A,B or C.
If the head is porous then the only lasting solution is to fit the later revision C head.

 

[RAF_S7]

The coolant system in a modern car is a sealed loop, so basically it should be fill and forget.

The coolant is going somewhere, and if you can't find it leaking under the car, then it may be going into the combustion chamber (via cylinder head gasket usually) and being turned to steam. A good way to check is when the car is warm, watch the exhaust pipe and have someone rev it hard, you will get plenty of white smoke if there is a problem in that area.

 

[Jamie TDI140]

If you have a good search on the A3 8P forum there are loads of similar cases as yours....
The early 2.0 tdi engines suffered from porous cylinder heads, so much so that VW/Audi revised the cylinder heads 3 times, until about 2006 at the revision C head they finally seemed to have solved the problem.
That's not to say that every early engine with an A or B head will leak, many don't, but the earlier models were much more susceptible to head problems than the later ones.
If you pull off the engine cover and look where the 2 metal pipes that carry fuel along the cylinder head are you should be able to make out the part number of the cylinder head cast into it.
It will end in either an A,B or C.
If the head is porous then the only lasting solution is to fit the later revision C head.

So guess my next question is, how can I actually find out if it's pourous? Never even heard of it before haha.
I'll check the numbers tomorrow in the day light.

The coolant system in a modern car is a sealed loop, so basically it should be fill and forget.

The coolant is going somewhere, and if you can't find it leaking under the car, then it may be going into the combustion chamber (via cylinder head gasket usually) and being turned to steam. A good way to check is when the car is warm, watch the exhaust pipe and have someone rev it hard, you will get plenty of white smoke if there is a problem in that area.

I'll get the misses to give it a boot tomorrow after work, see what happens.

I went down to my local VAG specialist after work today and booked it in for Wednesday for them to have a look. I've used these guys before on my previous VW's and the guys really know they're stuff.

 

[JamesVAG]

Hey Dude any news on this I have same engine as you and just hoping this doesn't happen to mine, fingers crossed.

 

[Jamie TDI140]

Hey Dude any news on this I have same engine as you and just hoping this doesn't happen to mine, fingers crossed.

I only posted this today haha I'll post in here what the garage says on Wednesday. I did a proper search on here and found loads of threads with the same/similar issues. I'm just hoping it's one of the simpler fixes and not the more expensive ones haha

 

[JamesVAG]

Oh sorry didn't check the date yeah let me know mate. Been speaking to another chap on here and he said he had the porous cylinder head problem. I will be praying for you that it isn't that?

 

[Jamie TDI140]

I forgot to update this.

I took it down the the garage and he pressure tested it while running for nearly an hour and he didn't spot any loss of coolant, but did say it wasn't going somewhere. He took off the pipes to EGR cooler and couldn't see anything, couldn't see any obvious leaks anywhere, and i confirmed I never see any puddles or marks on the floor when it's been parked. Also he asked when I start it up does it ever feel like it's misfiring and loads of white smoke comes out of the exhaust (which it doesn't) which would imply water sitting on top of the pistons.

So we're unsure at the moment what it could be and have been advised to keep using the car as normal and keep a check on the levels and note how often I have to top up and keep checking for leaks and the like... but we both agreed it's got to be goon somewhere just unsure where at the moment. Hmmm....


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[Boydie]

Noticed low coolant level in my wifes 1.8TFSI and smell within the cabin - took it back to the dealer and found the pump leaking, cureently being replaced under warranty along with water pump.

 

[Jamie TDI140]

Noticed low coolant level in my wifes 1.8TFSI and smell within the cabin - took it back to the dealer and found the pump leaking, cureently being replaced under warranty along with water pump.

What sort of smell was it? I did notice a funny smell the other day but I just thought it was something coming in from outside as I had the heaters on at the time.

 

[kash_v]

Check under the dash, could be a leaky heater matrix.

 

[SAiLO]

Are you actually losing the coolant?
Does it drop below minimum level in expansion tank?

 

[Boydie]

@Jamie TDI140 open up your coolant tank and take a whiff, then just keep a sniff out for it within the cabin

Pretty hard to explain the scent of coolant over the internet lol

 

[Jamie TDI140]

Check under the dash, could be a leaky heater matrix.

i'll investigate later I think, see if I can spot anything.

Are you actually losing the coolant?
Does it drop below minimum level in expansion tank?

Yes, since buying it in March, the warning light on the DIS has come on 2/3 times, with the coolant being below the minimum mark.

 

[Jamie TDI140]

@Jamie TDI140 open up your coolant tank and take a whiff, then just keep a sniff out for it within the cabin

Pretty hard to explain the scent of coolant over the internet lol

Righty'o, i'll have a "sniff around" later......
there is zero discolouration though, it's as pink as it was when it went in.

 

[bobby singh]

I just changed the head on our touran bkd was losing coolant and I even by passed the EGR.
Its a 2007 model with C revision and it still leaked so C doesn't mean you are safe.

I've now installed a AMC head.

Runs a lot nicer now.