# Mysterious coolant loss?



## pezftw (Aug 1, 2015)

Seem to be loosing coolant with no obvious signs of leaks, I'm praying that it's not the head gasket. Happened twice now since I got the aux pump working. This morning I started it when I was setting off for work and got the coolant warning on the DIS and it was about 1/2 inch below minimum, topped it up to the max and when I got to work and popped the bonnet to check the level it was about an inch past the max level. Going to get a sniffer test done on Wednesday next week to rule out the head gasket but any one else have any ideas what it might be?

Any input greatly appreciated Pez


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## Jez xbx (Oct 24, 2014)

not sure the inch past the max when warm is a worry?
there was a post about it recently, basically the coolant expands when warmed up?
will have a look for the thread....

viewtopic.php?f=2&t=1190090&p=6610241&hilit=coolant#p6610241


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## firediamonduk (Dec 24, 2013)

As Jez says, the coolant will expand when it is warm so being slightly over the max is not a problem. When you get it sniffer tested ask them to pressure test it at the same time... this should show any leaks if not HG...


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## outdoor stevie (Nov 24, 2013)

Are you sure you're not losing it from someplace and it's dripping down and out? If you put some bits of wallpaper on the ground under the car white side up when it's left overnight then check in the morning to see if there are any leaks then you might get an idea. It's a cheap and easy test.

Stevie


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## cam69 (Dec 22, 2011)

Could be waterpump they are common to start leaking just had to replace mine because of this and it was only 2 years old.


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## Mondo (Feb 20, 2009)

Mine would leak a little every now & then, funnily enough after I changed the gone-brown OEM one for a whiter-than-white knock-off. After fiddling with hoses & clips, and observing pink coolant around the expansion tank in odd places, I came to the conclusion that the fecking tank was leaking at the seams.

Got a new OEM one from Audi, fitted it, and bingo! No more coolant leak/drop.

Pay cheap, pay twice. 

Maybe check the expansion tank for 'pinkage' and swap it out for a new OEM one; might be worth £35 or so to eliminate the possibility.


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## Donay (Sep 30, 2013)

You can check you oil for a white slimy film which occurs when coolant mixes with oil, also white exhaust out the back.


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## pezftw (Aug 1, 2015)

If i can smell coolant through the heaters sometimes it's less likely to be a head gasket issue right? This is strange now because it was fine for the few days after i topped it up (i was paranoid so was checking it after each journey). Then i smell coolant coming through the heater vents and its dropped down to in between max and min.

What could cause it to be intermittent like that?

Cheers Pez


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## rusTTy_racer (Sep 7, 2015)

By that you mean in the car? Could be the heater matrix :?


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## pezftw (Aug 1, 2015)

Yeah I thought that too, I'm praying it isn't that either. Not in the mood for ripping 2/3 of my interior out. I'm stumped as to why it would be intermittent though. Fine for days then it drops like that. I'm hoping it's just a leaky hose somewhere and the smell is being dragged in from the engine bay.


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## Sandy (May 5, 2014)

Check under the crank pulley as it may well be the water pump if not replaced for a while.
I had the same symptoms of loosing coolant randomly and not all the time.

Happened to mine for months of thinking where's it leaking put of. Got it up on the work ramp and found the leak immediately coming from the crank case cover timing belt side and replaced the full t belt kit a week later.


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## rusTTy_racer (Sep 7, 2015)

Agreed, but still possible (I have had to do them in the past on my motors but not for a few years.

Pressure test on the coolant must be the way to go. Good luck :roll:


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## spen (Jun 10, 2014)

Just had mine done recently. Was leaking from where the heater pipes go into the bulkhead. Was quite hard to find as it is behind the heatshield. Worth a look there. Two rubber seals that break down with age. Although the seals arnt available without buying the pipe.


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## pezftw (Aug 1, 2015)

spen said:


> Just had mine done recently. Was leaking from where the heater pipes go into the bulkhead. Was quite hard to find as it is behind the heatshield. Worth a look there. Two rubber seals that break down with age. Although the seals arnt available without buying the pipe.


Where are they located exactly? Was it a big job to replace them?


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## mrvandango (Jun 1, 2014)

I had a slow leak on mine too. When poking around I noticed a small patch of coolant on top of the gear box, which turned out to be coming from the black plastic flange at the end of the block that the temp sender sits in. When I took it off to replace it I found the rubber o ring had a kink in it and had swollen up. Must have been like it for a while I think.


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## spen (Jun 10, 2014)

pezftw said:


> spen said:
> 
> 
> > Just had mine done recently. Was leaking from where the heater pipes go into the bulkhead. Was quite hard to find as it is behind the heatshield. Worth a look there. Two rubber seals that break down with age. Although the seals arnt available without buying the pipe.
> ...


Where the heater pipes pass into the bulkhead. They're clipped together. . Have a look at the two heater pipes direction from the engine


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## Sandy (May 5, 2014)

Was it repaired and forgotten about :arrow: :-|


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## pezftw (Aug 1, 2015)

Sandy said:


> Was it repaired and forgotten about :arrow: :-|


I thought it was air locks in the system so i drained it and re-bled it, whats worrying me is that the coolant system is staying pressurised when it cools down. Which is leading me to believe there is exhaust gas leakage, if i remove the pressure, replace cap and start the engine the pressure doesn't build straight away so i'm stumped.

It's booked in for a full diagnostic (leak down tests etc) on tuesday so i'll keep you posted. 
My gut feeling is head gasket or cracked head though -.-. Although I'm getting coolant loss i have no overheating issues, no mayo, no oil in coolant no real symptoms of a exhaust gas into coolant leak I've just got a bad feeling. I can hear bubbles being pump around by the after run coolant pump which i'm hoping is just air pockets being dislodged after a run and not exhaust gases. Can anyone else hear bubbles when your AUX pump is running? [smiley=bigcry.gif]


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## outdoor stevie (Nov 24, 2013)

When you say you have checked for leaks what did you actually do? Is your undertray still on if it is then remove it have a drive about park up and give it a good rev and switch off, go back and examine underneath for drips and coolant. Let it cool off then start up and let it run until hot and observ temp on the air con unit switch off and let cool again and examine again, the coolant must be going somewhere either internally or external. If the bottom of your car is all crappy then you need to clean thIs of in order to see you may need to remove some stuff and get in there with some lights to see what's what in order to track the bugger down.

Stevie


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## Sandy (May 5, 2014)

pezftw said:


> Sandy said:
> 
> 
> > Was it repaired and forgotten about :arrow: :-|
> ...


Lets hope hey find the problem


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## pezftw (Aug 1, 2015)

Okay, he reckons I have a coolant leak somewhere. He's wiped the coolant crust off the locations where are possible culprits and I have to go back again on Tuesday next week. Relieved it's not the head but disappointed I don't have a reason to say to my girlfriend "I might as well put some forged rods in while the head is off".

Reckons it might be the radiator leaking, I'll post back next Tuesday for the final diagnosis.


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## Sandy (May 5, 2014)

pezftw said:


> Okay, he reckons I have a coolant leak somewhere. He's wiped the coolant crust off the locations where are possible culprits and I have to go back again on Tuesday next week. Relieved it's not the head but disappointed I don't have a reason to say to my girlfriend "I might as well put some forged rods in while the head is off".
> 
> Reckons it might be the radiator leaking, I'll post back next Tuesday for the final diagnosis.


Well glad it's not a head gasket issue and will hopefully find out what it is although I'm a little worried at why he didn't find the leak there and then?. :? 
You need to take the sump off for rods but can always lie to her as it's only a little white one :lol:


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## pezftw (Aug 1, 2015)

I thought that myself, but the leak is quite intermittent. When i'm driving the car it's fine. Then i can leave it overnight and in the morning it will be 1" below minimum with no obvious leaks anywhere. There was some crust around the waterpump and water around the radiator. Water pump was changed 10k ago so leaning more towards it being the radiator, see if any crust reappears on tuesday when i go back. I've still got it in the back of my mind that it's a cracked had or the head gasket though [smiley=bomb.gif]


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## JohnD (May 7, 2002)

Hi,

As mentioned I also had a leak from the heater matrix pipes hard to spot with the heat shield and never any visible signs under the car. Audi wanted £40 + each so I repaired mine with silicon coolant hose for £11 and have no further need for the pipe heat wrap and it matches the blue silicon pipe scheme on my car.

I used 22mm pipe http://www.ebay.co.uk/itm/190885058500? ... EBIDX%3AIT

The 19mm pipe would also probably be ok as the silicon is quite flexible.

You can get the clips off near the bulkhead to remove the old perished pipes without the need for removing the 'quick' connectors on the heater matrix.

John.


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## pezftw (Aug 1, 2015)

JohnD said:


> Hi,
> 
> As mentioned I also had a leak from the heater matrix pipes hard to spot with the heat shield and never any visible signs under the car. Audi wanted £40 + each so I repaired mine with silicon coolant hose for £11 and have no further need for the pipe heat wrap and it matches the blue silicon pipe scheme on my car.
> 
> ...


 cheers, I'll give those a check later. I'm guessing they're the ones behind the TIP that go through the bulkhead then?

Anyone know if this is normal for a fully warmed up engine? Seems to go away if I give it a booting then when I let it idle for a few minutes it returns.


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## Sandy (May 5, 2014)

Condensation from the exhaust for this weather is normal for all cars.

If you're saying there was crust around the crank area where cambelt resides and it's pink like the coolant my bet is with thay being the issue as I had this on my tt in 2014 and did mention it on one of my threads in here.


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## pezftw (Aug 1, 2015)

Thought i'd give an update to this, my cars booked in for the turbo to be done on Monday as it was a suspected CHRA cracked housing leaking coolant inside the turbo. I started to get a misfire so i bought some coil packs too, thought i'd check over the plugs to make sure my gut feeling of it being the head gasket wasn't right.~

Turns out one of my coil packs was on it's way out like i had thought, but when i checked the last plug it was completely clean [smiley=bigcry.gif] i also shone a torch down into the bore and the piston was sparkling clean too. ~

Looks like it might be the headgasket after all? Can't get in touch with my indy until monday so guess i'll have to await confirmation of the bad news and the increased hole in my wallet.

Just hope driving for the last 2000 miles thinking it wasn't my headgasket hasn't messed up my bore.


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