A4 3.0L TDI SE Q - Coolant Water useage?

[Pauls898]

Was just checking my Audi A4 3.0L TDI SE Q over after a weekend away in The Gower, about a 300 mile round trip and found that my coolant water reservoir was almost empty!!!! I had to add a good pint of water to bring it back up to the MIN line?
Question is, I never had no warning lights come on to tell me it was running that low, and it was well below the MIN mark? and looking around the engine/radiator I can see no evidence of any leaks or anything strange?
The last time I took this car into the Audi main dealer they assured me that mine 09 plate wasn't effected by these faulty water pumps I have read about on the 3.0L models? Also I never noticed the temperature gauge go above normal at all during the weekend?
A real mystery?
I shal have to keep a close eye on this now if it happens again I will have to take it into the dealer to be checked over?
Paul

[robtt09]

I have same age car and just had second service .Garage checked vin number and mine not due water pump fix. But it does use some water so maybe just one of those things with this engine

[Pauls898]

Yes Thanks for your comment, yes I have noticed it go down a bit before, but then I think I didn't check it for about 1 month and been on a few long jouneys, came to top up the windscreen washer and notice the coolent tank was nearly empty.....? I think I had to pour in about 1 pint to bring it back to the min level while it was cold? Will have to keep an eye on it now see if it drops again? but theres no signs of any leak or water staining if there was water leaking from a hose etc, but its so tightly packed in the engine bay its hard to tell. Yes its a great engine car drives really well :-)

[ScottyUK]

My old B6 S4 had a minor issue like you describe. My dealer couldn't find the issue during the warranty period on three occasions.

6 months or so outside the warranty and they found it. The lower casting has a pourosity issue. i.e. it was a manufacturing defaect where the lower block was slightly pourous. I obviously claimed it was a pre-existing condition and should be convered under warranty. Audi UK said not.

I got offered 40% contribution by Audi UK and 10% by the dealer. That left me to find £5k on a car worth around £10k.

No chance!

I px'ed it at full valuation and got shot.

Don't get stuck with the same. If you are losing coolant get on their case and don't stop until it's resolved .... during warranty!

[Pauls898]

Just an update on this? I have done about 120 miles and already the coolent level has gone down half an inch from the MAX line again!! But strange thing is theres no signs of any leaks? no wet patches? nothing? I do hope its not a gasket or engine block problem? Car is now booked into my local Audi dealer, so they can investigate the problem? It obviously isn't right to be using that much water in just 120 miles?????

[Geordie Amanda]

My 10 plate lost a fair bit of water too, but when I mentioned that the level was below the min on the expansion tank, I was told to look again when the car was hot. Funnily enough when it had it's service a couple of months ago the level was above the max slightly, even when the car was cold!. Currently it is still looking full, but I smell a rat and will keep a close eye on things.

[Pauls898]

Well you should always check the level when its cold, as the water expands when hot? Normally mine is at just above the MIN level when cold and rises to the MAX when hot. But lately it was also empty when cold :-( I had to add a pint of water to bring this back to the MIN, now ever after just 120 miles its dropped by half an inch already and theres no visable signs of any leak?? non any white staining around hoses that I would have expected to see? So either the head gasket has failed to one of the cylinders or its going into the oil??

[Geordie Amanda]

My expansion bottle looked almost empty! And if this was the default and correct level, why is it now a lot higher after the service? I am not convinced by their story :(

[Dtom]

I have the same problem (just one more in a list of problems) but my local garage can't identify where the issue is, this is on a 2008 2.7TDI.

David

[Pauls898]

Well just an update? I took my car into Audi today, they kept it till about 4pm, they inspected and as I said they couldn't find any leaks? They then pressure tested the cooling system to 2Bar and said that the pressure remained constant? What they did do was contact the main Audi technical at the factory who sugested removing the EGR valve and checking that for ingress of water, said mine was clean but fitted a new gasket and re-assembled and re-tested. I have got the car back will use over weekend and see if it continues to use water? if so I will have to book it back in for futher investigation? Buit I check it when I got home and they have filled it right upto the brim!!! well over the MAX mark lol. We shall see how it goes? and I shall report back?

[Pauls898]

Well an update and it's not good news :-(.
With just driving 250 miles at the weekend the coolent level has gone down from the MAX mark to the MIN mark :-(
Car is now booked back into my local Audi dealer for further investigations...? Watch this space?

[theskyfox]

Doesnt sound good :-/. Ive got the same engine as you, its just done its first 4000 miles and the water level has barely gone down much at all....

-Andrew

[Pauls898]

Exactely That's what I wanted to hear? I think the garage is trying to say "They all do that sir?"

[robtt09]

Yellow warning light came on last night on way home. Looked at manual and had to drive to an Audi garage (slowly!) as soon as possible. Went this morning and auxiliary water pump bust. Part in stock and fitted today..good service. Maybe this is why I have had some water loss ? Service Manager also asked if performance down but I had not noticed that. Seemingly, I would have been ok driving car for some time .What does the auxiliary water pump do ?

[rapport25]

I had the same problem on my passat around a year ago. I tried the cheaper option first of replacing the expansion bottle cap but it still kept leaking. Also no visible signs of a leak.

I started carrying around vag coolant along with 5 litres of distilled water to top up as of when required.

Finally I decided to get a great indy garage to look at it. He left the car running until it hit temperture and started removing the under tray and noticed it was full with water.

Diagnosis was a leaking radiator.

New radiator fitted and no leaks :approve:

Hth's Rappy

[Pauls898]

My question is would the radiator be coverred by the warrentry? Because they might claim the damage was caused by stone? and it would be very differcult to prove anotherwise? I would be interested to know what this Auxiliary pump is? Does that mean there is two water pumps in the system or are we referring here to the main one in the cooling system? Car going in on Monday there keeping it over night so they will have it for two days?

[rapport25]

I would say the rad is wear and tear and would not be covered. As for the aux pump. I would imagine this for the heating in the cars interior.

[Pauls898]

Car has gone back into Dealer today as the problem persists, they are convinced it is related to the EGR valve so they have orderred a new one from the factory? They say its a 7.5 hour job to fit it, so they have the car in for two days? lets hope their right???

My question is? does the coolent water flow though this EGR valve? otherwise why should this device causes the coolent to disapear from the system?

[rapport25]

Car has gone back into Dealer today as the problem persists, they are convinced it is related to the EGR valve so they have orderred a new one from the factory? They say its a 7.5 hour job to fit it, so they have the car in for two days? lets hope their right???

My question is? does the coolent water flow though this EGR valve? otherwise why should this device causes the coolent to disapear from the system?

EGR valve is to control the cars emissions and nothing more. Basically it regulates the fuel to air mixture. I would be going for a 2nd opinion if it was me.

[rapport25]

Your car is loosing coolant so its an internal leak or an external one.

Internal read head gasket. External read water pump radiator or pipework. It really is that simple.

[phatAvant]

Going to keep an eye on mine on the A4 now. We have a similar problem on our Mini, but every dealer Ive been to say its normal :confused:

[Pauls898]

The the question is they have had it on pressure test up to 3 Bar for 4 hours with not pressure loss?

There are not signs of water leaking externaly from anywhere?

They suspect an internal crack in the EGR Valve? so are replacing that?

If the fault persists then its got to be either head and gasket?

[rapport25]

The the question is they have had it on pressure test up to 3 Bar for 4 hours with not pressure loss?

There are not signs of water leaking externaly from anywhere?

They suspect an internal crack in the EGR Valve? so are replacing that?

If the fault persists then its got to be either head and gasket?

I would be asking how the egr valve effects coolant? If anything its the other way . Some EGR valves use a sensor that monitors the coolant temperture but thats it. This would not cause coolant loss.

[rapport25]

Going to keep an eye on mine on the A4 now. We have a similar problem on our Mini, but every dealer Ive been to say its normal :confused:

Regardless of what car you have you may loose a little over time. But having to top up weekly/monthly is not normal.

I only had to top up mine when my rad was leaking. Since then I have not touched it.

[Pauls898]

On this car which is a 3.0TDI SE Q it has what I beleave is an EGR Cooler so yes some coolent will be flowing though that part of it and they think it might have a small crack in between the cores? Well I suppose they have to start with the cheaper options before they go taking off the heads?

[rapport25]

On this car which is a 3.0TDI SE Q it has what I beleave is an EGR Cooler so yes some coolent will be flowing though that part of it and they think it might have a small crack in between the cores? Well I suppose they have to start with the cheaper options before they go taking off the heads?

That makes a lot more sense :approve:.

If it it has a cooler then yes I agree that could be causing your loss of coolant.

[Pauls898]

Just picked up the car from the Audi Main Dealer, work now completed :-) I got the service guy to show me the part they had replaced (EGR Valve) It looked like a tin box with several small tubes runing though the middle and on the outside were two water inlet and outlet nozzals for the cooling. It was designed in two sections I assume for each bank of 3 cylinders being a V6. It was clearly noticed that one half was all sooted up with gunk and the other looked "Steamed Cleaned" obviously because it had water though it? Lets hope this fixes the problem? will report back once I've done a few miles? Watch this space? ;)

[Pauls898]

Well an update, been driving around for a few weeks and to be honist, the water level is still going down!! So that was obvioussly not the problem? Car has been booked back in, so this will be there 3rd attempt and fixing this same problem, if they still can't fix it can I demand a new engine????

[titch74]

Hi,
New to the forum and recently bought my first Audi. It's a 2008 A4 3.0 TDi SE Quattro and unfortunately seems to have the same issue described in this thread, it seems to be using coolant on relatively long runs but shows no sign of where it's going. No sign of any leak, no trace of water in the oil, the car runs well and doesn't overhead but still the coolant level drops and requires topping up every 300mls or so.
Did you guys ever get the issue resolved? It would be good to be able to be knowledgeable about the fault before I take it back to the garage.

Thanks.

[Pauls898]

Hi, Sorry I should have said, it was the EGR valve at fault, after it had been replaced the coolent useage has since stopped :o

So I would ask your dealer to check this part, what happens is a very small crack appears in the water jacket of this device and so the water under pressure simply goes into the exhaust and obviously turns straight to steam, so you won't see anything leaking.

On a typical 300 mile jouney mine would go from the MAX mark down to below the MIN in the expansion tanks, shorter jouneys you couldn't really see much change?

But after it was replaced under the warrantry it's now curied the problem, but it took them three visits to fix it, as the first time they tried just changing the EGR Valve gasket, as this was a cheaper option to try first off.

I was convinced it was the head gasket, but luckly it wasn't......

[titch74]

Hi,
Thanks for the reply, I'm heading back to the garage on Monday so can see what they say about it. hopefully it'll be a warranty repair :o.

Cheers, will post again once it's fixed.