Volkswagen Mark IV Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
487 Posts
Discussion Starter · #1 ·
Hi all,

I seem to be losing water but can't seem to find where it's leaking out of.

I've checked all of the usual places for head gasket failure - even had it up on the ramp. Well pretty much checked everything apart from a pressure test.

Not a spot of water on the drive or anywhere i park - The levels were topped up about 2 days ago and now have dropped down enough to send the coolant stop warning on. Generally the levels stay high for a while (Checked almost every day), but then suddenly it drops without warning. This has happened about 3 times in as many months. When it does drop I have to use about half a litre of water/coolant.

The only thing I have done differently is use a different brand of coolant - but i'm thinking this is a coincidence. Anyone have any ideas?

Cheers
 

·
Registered
Joined
·
104 Posts
Hi Jase,

Had this very same problem and couldn't for the life of me work out where the coolant was disappearing to. Eventually found it, it was a very tiny hole in the radiator, it looked as if a small stone had punctured it. As it was so small the coolant would escape as steam rather than in liquid form and therefore leave no residue making it harder to track down.

Otherwise looks like you've done all the right checks (creamy mayonnaise type gunk in the oil cap, oil in the coolant, traces of white residue/rust in the engine bay, etc.) another simple one would be to check the coolant reservoir cap, see if it's still doing it's job. Also could be the water pump, the plastic impeller may have given up the ghost.

Anyway, good luck in finding the cause and report back with any findings.
 

·
Registered
Joined
·
1,686 Posts
Have you just changed your coolant? If so you may need to keep topping it up until the whole systems bled through properly.

Lay some card underneath your engine bay over night, if you loose coolant but no signs on cardboard then you might want to think about head gasket testing etc.,

No wet stains in any of the front footwells?

HTH
 

·
Registered
Joined
·
487 Posts
Discussion Starter · #4 ·
Hi Jase,

Had this very same problem and couldn't for the life of me work out where the coolant was disappearing to. Eventually found it, it was a very tiny hole in the radiator, it looked as if a small stone had punctured it. As it was so small the coolant would escape as steam rather than in liquid form and therefore leave no residue making it harder to track down.

Otherwise looks like you've done all the right checks (creamy mayonnaise type gunk in the oil cap, oil in the coolant, traces of white residue/rust in the engine bay, etc.) another simple one would be to check the coolant reservoir cap, see if it's still doing it's job. Also could be the water pump, the plastic impeller may have given up the ghost.

Anyway, good luck in finding the cause and report back with any findings.
Hi,

Thanks for the info - I reckon that the a small leak going to steam before I see it may be the problem. i've only just had a new water pump and there is no sign of over heating at the mo (Thankfully) I'll get a pressure test on it I think to check for leaks and force the water out of the hole.
 

·
Registered
Joined
·
487 Posts
Discussion Starter · #5 ·
Have you just changed your coolant? If so you may need to keep topping it up until the whole systems bled through properly.

Lay some card underneath your engine bay over night, if you loose coolant but no signs on cardboard then you might want to think about head gasket testing etc.,

No wet stains in any of the front footwells?

HTH
Hi,

The head gasket was done about a year ago - not ruling it out but will try the 'card trick' to see if i see anything. Problem is next door neighbour's cats sit under the car and may ruin the test!!

Thanks
 

·
Registered
Joined
·
233 Posts
Does the interior suffer from steamed windows? Check the carpet front and rear for dampness, it could be the heater matrix leaking.
 

·
Registered
Joined
·
487 Posts
Discussion Starter · #10 ·
Have you had the water pump replaced for a metal version?

Could also be head gasket
Yeah, the water pump was replaced for a metal one - plus it was only done about 6 months ago last time.

It may be early signs of head gasket but upon checking there are no other symptoms whatsoever of this problem. Again I have had this done.

Thanks
 

·
Registered
Joined
·
487 Posts
Discussion Starter · #11 ·
Does the interior suffer from steamed windows? Check the carpet front and rear for dampness, it could be the heater matrix leaking.
Yep, checked all carpets - not a spot of steam on the windows.

Just to add for everyone the water loss is very sudden - If I fill it up today, I could go 2 or 3 weeks with no drop at all - I generally check it every day now. Then the next day after only about 10 miles 'beeep!' very strange.

I'm thinking heater matrix or somewhere behind there as the dash is very warm when i get into the car even on a cold day.
 

·
Registered
Joined
·
487 Posts
Discussion Starter · #13 ·
GTIJASE - Sorry to jump in but is there a faint gurrgleing sound in your expansion tank when engine is turned off? Trying to figure out if this is normal or part of my water loss issue re: http://uk-mkivs.net/forums/thread/678438.aspx

anyone?
No need to apologise - it all helps! I haven't noticed any noises or bubbles for that matter. I do think there is pressure being lost though as I was able to (Carefully with the cap covered!) release the expansion bottle cap without the water level rising to try and exit the cap. I may even try replacing the cap as sometimes you lose water through there if it isn't 100% secure. I live by speed bumps so it's a possibility some is lost when going over them constantly.
 

·
Registered
Joined
·
842 Posts
this could be a long shot, but may help,

i just changed my temp sender and when i took out the old one water came out like a flowing river, there is a rubber washer that sits with it, water may be coming through there,

the 'sender' on my 1.8turbo is on the right hand side when looking at the engine under the side of the cover that you have to take off,

like i said may not be from there but no harm in looking
 

·
Registered
Joined
·
487 Posts
Discussion Starter · #15 ·
Thanks for all of your replies - i have my car booked in for monday to check the problem once and for all!
 

·
Registered
Joined
·
9 Posts
Don't count on it...I have had my car into my local dealership at
least 7 or 8 times before they managed to (hopefully, cross everything,
touch wood etc etc) fix the problem. Each time Ithey would hand me my
keys saying "yes, its all fixed now, we have tested it and there are no
leaks" only for me to get halfway to work the next morning and hear the
dreaded "BEEEEEEP!"

Interestingly, the last fix they did was to
change the new radiator they put on 2 weeks before. Turns out it was
blocked, and the pressure buildup was forcing coolant to get pushed out
of somewhere, even though nothing was actually 'leaking' as such.

Good luck anyway!
 

·
Registered
Joined
·
487 Posts
Discussion Starter · #17 ·
Well i've had all the tests done at my regular garage. As you guessed - nothing! No leaks, no loss via the pressure test.

I have notice a few mm drop and the test was done on Monday.

Will have to keep an eye on it. I use my car for work so could prove to be bad on long journeys.
 

·
Registered
Joined
·
487 Posts
Discussion Starter · #19 ·
Thanks - i've tried radweld in the past with other cars and whilst it cures the problem short term I ended up with blockages and blocked thermostat - plus overheating. It hasn't really gone down recently with a few motorway journeys. I think I need to find the cause of the problem so may mean taking the radiator off and running the hose through to clear any blockages.
 

·
Registered
Joined
·
4 Posts
I know this is an old post but i didn't want to start a new one because i have the same problem.

A few months ago i bought a Bora 130 Tdi and after a day or so of using it the coolant warning light would beep intermittently even though there seemed to be water in the expansion tank. I replaced the expansion tank with a new one because i heard the sensors play up on them. I replaced the cap a few weeks later.

I noticed just after that the water was turning brown so someone suggested getting the water pump done. A few days later the car started to overheat so i left it overnight. The next dai i topped up the water and took it straight to a garage just a few miles away and had the waterpump and cambelt replaced. The waterpump was knackered. Great all sorted i thought, but a month later the dreaded 'Beeeep' and the expansion tank is empty again. I've been topping the water up every few days without letting it get too low.

I've no idea where the water is going. The car doesn't overheat or smoke and the oil is fine. The car also drives fine. I know theres a possibilty that the headgasket could have got damaged when it started to overheat but there are no other signs.

Any suggestions would be greatly appreciated.
 
1 - 20 of 21 Posts
Top