Excessive water use

[WBray]

Hi guys
My car is drinking water like nothing else and I cant figure out where its all going.
The car has a little froth on the dipstick and a tiny amount of condensation on the oil filler cap, but nothing like you would imagine for the sheer amount of water being put into her.
Head gasket was checked by SCS Porsche who found it to be fine, the oil cooler did have a small leak but this and the housing has been replaced. When its parked up there is no signs of it leaking anywhere and no signs on the garage floor over night or a couple of days if she is parked up.
I am at a loss any ideas? She still drives fine though.

Thanks,

 

[Mike_Pollock]

Hi Will
I'd try a new coolant cap next. also they can be very difficult to bleed!

 

[WBray]

Coolant cap isn't that old but should probably consider it. True but nearly 4 jug fulls of water is to much even for a system which hasn't been bled properly? Which I would have thought SCS should have been able to do?
Cheers

 

[andy watson]

Blimey Will, that sounds serious and you only use this when driving? but not 4 jugs every trip?

 

[edh]

Sounds a lot - I'd be checking for leaks...get the car nice & hot & then look under the bonnet for leaks. they may not show when the car is cold. Also worth running the overflow pipe from the expansion tank into a container to see if anything is coming out.

If the coolant has been drained & refilled by SCS I would expect it to have been bled properly - they are good guys. What suggestions do they have for the fluid loss?

daft question maybe, but what level are you filling the expansion tank to?

 

[Lowtimer]

When you say they checked the head gasket, what did they do? I'm guessing a compression test and coolant analysis for exhaust gases?

It's got to be going somewhere, especially in those rather heavy-duty volumes. If it's not going into the oil or piddling out underneath (which apparently it's not) then either there's a significant steam gusher (such as through the pressure cap when hot) or it's going down the exhaust pipe as vapour. Which is back to the head gasket, or a cracked head perhaps.

 

[J4CKO]

Check your heater matrix also look for residue the same colour as the coolant, mien was leakign fromt he coolant elbow on the front of the engine as they are not reusable and had been reused, when brakign the overflow pipes weight going forward opened a gap to let coolant out, a hot engine means it just evaporates so you dont see any water, just an occasional waft of steam.

 

[tref]

Ah, one other water loss method I recall was a corrosion pin-hole in the hard-pipe over the exhaust manifold... because it leaked onto the exhaust manifold the water evaporated without a trace... might be worth looking for/at.

Regards,

Tref.

 

[Frenchy]

I will echo what Tref has said, check the hard water pipe over the exhaust manifold they rust on the bottom and spray the water on to the manifold which then evaporates.

 

[Mike_Pollock]

Thats more water than I was thinking about!

As has been said - its going somewhere - looking when its hot and running is probably the best idea.

 

[robdimond]

I would say worth hiring/buying/making a pressure tester so you can put a bar or so of pressure in the header tank and look for a leak without the heat/noise of the engine. You will see instantly if it's not holding pressure and will be able to look for the drips with no chance of them evaporating away.

Good tutorial here:
http://arnnworx.com/h2o-pump.htm

 

[WBray]

Not 4 jugs every trip, but probably 4 jugs over the last 1.5-2months. I fill to the maximum level on the reservoir and soon enough its back down the minimum level.
I'm not sure how SCS checked the head gasket tbh but with their reputation and knowledge/experience of 944's I would like to think its been done properly, and plus with the amount of water being lost I would expect the engine to be overflowing with froth rather the small amount on it. I do need to contact Andy as I have to return something to him and am planning to see what he says about it then, but with work been pretty busy and havn't had the chance yet, but when I do I shall see what he says.
Shall get her up to temperature and have a look underneath and see if I can see anything leaking anywhere or any steam, and look into the possibilty of pressure testing.

Thanks for all your input guys!

Will

 

[Zloca944]

Try to see if your carpets are wet in the car under the dashboard.You might have some heater leak inside the car.

 

[alwigley]

I recently found a pinhole leak in my lovely new radiator which was causing something similar - showed as tiny waft of grey smoke when engine at full temp with bonnet open but otherwise you would no have known...... Pressure test as previous poster mentioned will find it, but checking a HG can only be done properly by taking the head off so could well be small internal leak when running.... Any grey smoke from exhaust ?

 

[eddieedmo]

it does sound like head gasket, there should not be any frothing in the oil or condensation under the filler cap , if the head gasket has not been changed it will need doing.

Nick

 

[George Elliott]

Will,
I'd fill the coolant to correct level, and run the car at tick over on a ramp for half an hour with the bonnet open.

If the rad or other obscure part such as the hard pipe is pinholed, it will be evident as you watch for the leak.

My car was leaking at the heater valve, very very difficult to spot but I got there eventually.

If you do not find anything then the HG probably is the culprit.

Mayonaise is not a reliable indicator.

good luck
George

 

[zcacogp]

ORIGINAL: WBray

I fill to the maximum level on the reservoir and soon enough its back down the minimum level.

Does it ever get below the minimum level?

If not then I suspect it's the same as every other 944 I have ever come across, and perfectly normal. For some reason, if you fill my S2 up to 'Maximum' it spits it out to just below the 'minimum' level and settles at that. And it does so very quickly - within the first few minutes of it being started after refilling. I too was worried about it for a while but a bit of reading around suggested that this was perfectly normal and nothing to worry about.

To reiterate, if it appears to go from 'Max' to 'Min' very quickly, but never gets below 'Min', don't worry about it. If it continues to use beyond this point, or has mayonnaise on the filler car, or any one of a hundred other signs of problems, then it's worth investigating.


Oli.

 

[edh]

Very good point. My s2 also sits just below min.

 

[WBray]

Don't believe carpets are wet, but I shall check again tomorrow hopefully.

Looks like shall be looking into getting a pressure test done fairly soon then.

I dont know if it goes below minimum as soon as I notice its low I top it up (normally check the levels when I've been on a short trip and found the fans running after i turn the engine off)

Sounds like a plan George though havn't got access to a ramp to easily :/

Not noticing any smoke from the exhaust.

does it always drop that quick though Oli and Edd and if so were does it go?

 

[zcacogp]

Yes, it always drops on the first decent length drive I do after topping up. I think it spits it all out of the overflow - I've never looked to find out. Gets down to a bit below minimum and stops just fine there.

I bet this is exactly what yours is doing as well. Tell you what, save the money you were going to spend on that pressure test and watch where the level gets to for the next few times you drive it. When it gets to the 'Min' (or a bit below), don't fill it up, just leave it. Watch the temperature gauge very closely next time you drive it, and check the level again. If it doesn't get any lower then buy me and Ed a beer should we ever meet.

Deal? []


Oli.