Sudden coolant loss...head gasket??

[cara_essex]

Hi guys,

Some help please for a damsel in distress!!

My stupid car is playing up again. Do you know I was led to believe these v-dubs were a good reliable make and ive had nothing but **** from it.

Anyway..just got in from being rescued after breaking down on the way home... was driving along and the engine temp needle, which normally lays dead central at 90degrees... anyway I noticed it was nearer 110!!! As i was thinking s**t i need to pull over a red light flashed up on the ignition so that was that, hazards on and I stopped immediately.

My manual told me it was the coolant warning lamp... quick call to my dad who came to rescue me and announched that I had a coolant loss somewhere in the system. He was pouring water in and it was vanishing. Anyway he filled it up with water and managed to drive it home... only a 5 min car journey and by that time the engine temp was scorching.

He rubbed the exhaust end and says that he reckons head gasket has gone as there was wetness at the exhaust end or something which shouldnt be there????

Any ideas guys as my dad was just using his general car knowledge whereas you all know VWs perfectly.

Please tell me its not the head gasket as I believe theyre rather expensive

Anyway its a lovely blue car only 82k miles....any takers????

Seriously...any ideas as you all know golfs or are these symptoms pointing to the obvious which i have stated above.

Thanks

Cara

[cara_essex]

Anyone?.....please

thanks!

[nicmas2000]

hello have you got air bubbling in your header tank? what sort of car have you got? i'm also thinking that water is a biproduct of combustion so some water at your exhaust is ok but if you cant see where the water your putting in is going then h/g i guess

[KeithS]

Fill it up with water and check for leaks, it should be fairly obvious if its losing so much coolant. I'd hazard a guess its more likely to be a split hose or a punctured radiator than a head gasket.

[saint_78]

from what i understand about head gaskets if your car is cold and you check the oil dip stick if water/coolant is mixing with the oil it will leave you with a creamy-brown mix rather than your standard oil

and water in your exhaust i agree with nicmas2000 water can build up in your exhaust system especially if it doesn't get hot enough this can cause your exhaust to rot inside to out.

also again good idea to check all the hose's and clips for splits and aging and if coolant level drops quickly it should be obvious

what model car do you have?

[Crasher]

Cara, what is the engine code or at least size and car year?

[cara_essex]

Hi everyone,

Its AEE, 1998 Golf 1.6, mono-motronic 55kw. petrol multipoint injection (thats as much as i know!)

Anyhow, a mobile mechanic has looked at the car now and ITS NOT THE HEAD GASKET (Phew ) he changed the thermostat and the thermostat housing was cracked so we're awaiting that part..although for now hes somehow disconnected the thermostat so the car is driveable but running much colder than it should be.

I did start another post regarding the cracked thermostat housing as i had a couple of questions:

Why did the t/s housing crack in the first place, just one of those things?
Where was the coolant going? And why would this being cracked cause the coolant to leak as i thought the coolant tank and the thermostat housing arent near each other? (Sorry this is probably very obvious, but i dont know cars!)

Thanks

[Crasher]

The thermostat top cover failing is very common and happens because it is under engineered although the replacement part is stronger. The coolant leaks because high pressure builds up in the system and this is released from the expansion bottle cap to try and prevent damage elsewhere, such as a burst heater matrix that would blow boiling hot water all over your feet.

The problem with driving it as you are is, as you point out, the over cooling. This will make the ECU inject more fuel which the lambda sensor will try to correct but it won’t be able to as the level of over fuelling will exceed the programing window. The lambda sensor will then shut down and there will no correction to the over fuelling at all so the catalyst will then receive a very rich mixture which will cover it in soot and it will also shut down. I have seen lambda sensors and cats permanently damaged by this in a few hundred miles.

[cara_essex]

Hi Crasher,

Thanks for the run down..it all make sense now!

Its all sorted now, the mechanic changed the thermostat & thermostat housing and bill was £60 which was a big relief compared to when we were assuming the head gasket had gone. Phew!

Luckily i avoided driving the car atall whilst the thermostat was disconnected..the mechanic said it was ok to drive but he obviously knew it would only be for a couple of days whilst he got parts. For the obvious reasons which you stated, no decent mechanic would recommend ragging it round for a couple of hundred miles whilst its in that state (cant believe the damage it can cause!)

On the other hand, i did used to get a funny vibrating rattly type noise only ever at 2400rpm...could this have been something to do with the thermostat housing being on the way out as since new parts gone in, its not done it so im hoping thats it now for a while. Cant afford any other suprises with this car!!

Thanks for the help people, appreciate it

Cara

[Crasher]

The noise coming and going is odd. To prove the point though, last week the thermostat cover on my mothers 97 Polo 1.4 8v failed and I was rushed off my feet so I pulled the thermostat, put the cover back on and ordered the parts. We didn’t get time to fit the new parts until today and already the car had logged a lambda error and that was just a few short journeys locally.