odd coolant leak

[s2driveruk]

Car has been on song all year...went to leave parents last night and greeted with a frying pan sized wet patch on the driveway. Couldn't see anything dripping but blotting it, definitely pink coolant. Got the car home and parked expecting another puddle...nothing? Left it running to get fan kicking in and nothing, no obvious wet spots in the engine bay.

Any ideas...was expecting a simple find log. Isn't water pump as pulled the cambelt cover to check

[spink]

aux water pump gave a similar problem to me last year

[Ross]

May be worth looking for the tell-tale signs of pink residue on the underside as a clue to where it came from... I had a leak on my old coupe that became apparent when it got quite hot, found pink crustiness around the radiator end tank where it was weeping. Didn't always occur either, for a while...

[jade]

aux water pump gave a similar problem to me last year

Second that

[Henkjan]

could also be as simple as a hose clamp not doing it's function anymore (had that a couple of weeks ago)

[s2driveruk]

yeah been looking for the usual little crystal farm that starts with a leak but nothing obvious....i'll give it a run later and then park up again one proper hot and see what clues it offers up. I think could be the aux pump too looking at it but would have expected there to be some kind of trace of moisture given the amount on the floor.

Cheers for the pointers gents

[UrS4boy]

...Any ideas...was expecting a simple find log. Isn't water pump as pulled the cambelt cover to check

In my experience, it *might* be one of two things:

1. auxiliary after-run coolant pump - http://forums.quattroworld.com/s4s6/msgs/21503.phtml

2. automatic climate control heater valve - this is the issue with my UrS4 - only seems a small puddle when it is cool enough for the heater to actually be on.

Here is a photo of a RHD heater valve (and the blue climate control temperature sensor)

[Rusty]

Coolant overflow from the header tank. Could be due to a loose cap or airlock. Check the cap is sealing and that the level is at min when stone cold. If the temp gauge is giving slightly odd readings or the fan isn't kicking in at the right point (90+2), then it's not pressurising properly. BTDT. Could be a pinched seal in the cap.

[Cottis]

Watching this thread closely as mine is losing a little water as confirmed in another post. It is going in for a service next week Tuesday, so will post up any further news then. Hoping it is dodgy header tank/seal etc etc rather than the head.

[Rikki Kitto]

Last time mine leaked it turned out to be the o rings on the water inlet manifold, if they haven't been changed for years they go rock hard and give up.

[jade]

In my experience, it *might* be one of two things:

1. auxiliary after-run coolant pump - http://forums.quattroworld.com/s4s6/msgs/21503.phtml

2. automatic climate control heater valve - this is the issue with my UrS4 - only seems a small puddle when it is cool enough for the heater to actually be on.

Here is a photo of a RHD heater valve (and the blue climate control temperature sensor)

Hi Dave,

I know I have commented before that I do not have on of theses valves or had not seen it , are they only fitted urs4 and s6 cars or do B4 have them also hidden some where

Thanks

Wayne

[UrS4boy]

Hi Dave, I know I have commented before that I do not have on of theses valves or had not seen it , are they only fitted urs4 and s6 cars or do B4 have them also hidden some where. Thanks. Wayne

I did say *might*. I assumed that all B3/B4/C4s with the automatic climate control would have the vacuum-actuated heater valve.

I can't remember whose car has or hasn't any specific parts or not.

[jade]

I did say *might*. I assumed that all B3/B4/C4s with the automatic climate control would have the vacuum-actuated heater valve.

I can't remember whose car has or hasn't any specific parts or not.

As far as I am aware on my LHD RS2 water is circulated all the time and the is a flap that controls hot or cold, does this control the flap ? or is it electrically operated like I thought

[Error404]

Hi Dave,

I know I have commented before that I do not have on of theses valves or had not seen it , are they only fitted urs4 and s6 cars or do B4 have them also hidden some where

Thanks

Wayne

Its a URs4/6 thing i think, LHD auto climate B4 cars only had a coolant temp sensor (with similar blue plug).

[europeanme]

it must be something to do with the time of year as I've got the same bizarre problem....a puddle but not evidence of a leak...