1600 Gti - Using Water

[weejp 0]

Hi all

 

Question: Why after having the headgasket, valve stem oil seals, timing belt kit, throttle body cleaned out, new oil, etc, etc done by reputible, reliable garage - would it still be using water?

 

I have perhaps driven 200 miles since the work was carried out. All issues that existed before have gone ie. nasty smell but the radiator light comes on after a few uses. Car doesn't get much use and journeys tend to be short bursts. No leaks anywhere - car is garaged and floor is dry. Can't understand it??!! I will take it back to garage as they have been good but wonder if anyone might have an idea of what's going on.

 

Also it's been pretty dire in terms of fuel consumption since the work was done, manky air filter was replaced last week but no improvement and that's using super-unleaded - again and ideas on that one? It idles happily at 1,000 - 1,100 rpm - it was set at that due to hunting all over from 900 down to 500 (cut out) but that was before changing air filter and reckon it could come down to 900 - 1,000 would that help in any major way?

 

Cheers

[pip470 61]

Have you checked the colour of the oil, just make sure its not mixing with the water there. they could of disturbed the liner seals.

[gav_mi16 0]

I had a similar problem, i.e. water consumption with no water leak. It turned out to be the expansion tank cap! As the system pressured up, the worn cap spring would be pushed open and water would leak through the overflow, as this only happened when driving I didn't notice.

[weejp 0]

I had a similar problem, i.e. water consumption with no water leak. It turned out to be the expansion tank cap! As the system pressured up, the worn cap spring would be pushed open and water would leak through the overflow, as this only happened when driving I didn't notice.

 

That sounds plausible as I've noticed a small amount of water on the battery. I'm very hopeful that will be the problem.

 

Question is where do I get a new or good radiator cap?

 

Cheers.

[MerlinGTI 3]

Halfrauds supprisingly enough ( I mean for them like, im not taking the piss lol)

[weejp 0]

Halfrauds supprisingly enough ( I mean for them like, im not taking the piss lol)

 

Seriously? - that's a bit of a surprise - thanks.

[welshpug 1,657]

liner seals not changed?

 

I'd take it back to the garage and ask them to do a pressure test on the cooling system, should soon show up any issues.

[Grim.Badger 15]

I've had pinhole leaks in hoses do this before, they only leak when the system is pressurised and hot. When the engine is cold have a good feel around all of the hoses for weak points, goo caused by drying antifreeze or water.

[DamirGTI 342]

Worn/leaky expansion bottle cap could be nasty thing sometimes , as the coolant system wont be pressurized which can lead to serious internal damage from overheating when you switch hot engine off .. water temp will climb rapidly way past 100deg. boiling out and creating steam pockets inside around coolant passages , leaving metal surface without the contact with liquid medium creating thermal stress which can lead to metal cracking (my cylinder liner cracked because of this leaky exp. bottle cap)

 

But , i don't quite understand this , you've actually spotted the lack of coolant inside the exp. bottle or you're referring just to the switching radiator light on the dash as a sign of a problem ? if it's just the radiator light switching on/off it's common problem and just needs cleaning of the sender internals free from mayo crap ..

 

Damir

[weejp 0]

Have you checked the colour of the oil, just make sure its not mixing with the water there. they could of disturbed the liner seals.

 

Yep, checked that and all is good - no nasty mayonaisse or anything - also checked oil and it is as clean as a whistle.

[weejp 0]

you've actually spotted the lack of coolant inside the exp. bottle or you're referring just to the switching radiator light on the dash as a sign of a problem ? if it's just the radiator light switching on/off it's common problem and just needs cleaning of the sender internals free from mayo crap ..

 

Damir

 

Thanks - Just going on the dash light, and trusting it - as it previously highlighted the headgasket issue and it was fooked I seen it in pieces!!! But I also did a manual check and had to top up the tank with a fair bit of water.

 

I have purchased a new radiator cap and it's in place (although the old one looked fine, how do you know it's duff?) so I'll take it from there I suppose.

[grandos 16]

You can't tell if its duff as its normally just the spring is slightly too weak.

 

However if you try to undo the cap and it falls apart then its duff

[Tom Fenton 1,542]

Easy way to check, is to run the overflow pipe from the header tank into some sort of container, anything will do, just cable tie it to something in the engine bay. If your missing water collects in there, then it points to a duff tank cap. If not you will have to look elsewhere for it!!