Puzzle: where is all my water going?

[SiD the Turtle]

So the other day I broke down on the M4 when the car overheated because the water tank was empty. I had filled it up a few days beforehand because it had its MOT. After a top up from the AA to get back home, Mr AA noted that when I was pulling away white smoke was coming out of the exhaust and then he used what looked like an ph test strip in the water tank which came out green, to which he said there was petrol gases in the water and the gasket had most likely gone.

So I took it down to a local garage and they said that there was nothing wrong with it. They pressure tested it and proved there was no leak, said the oil was the right colour with no sign of water in it and there was no sign of white smoke coming out of the exhaust.

Since then I've taken it for a spin with someone following and the exhaust seems fine, the temperatures remain steady and the car drives well. The only new problem which occurred a couple of days before I broke down is that the car is idling a bit off, which I put down to the engine needing a servicing. Problem is though, in the 9 mile drive to work the water went from max to half way between max and min. I've let it cool and topped it up and it stays steady, there's no water dripping onto the drive and no water coming out of the exhaust. Another drive- another half of water gone.

Where is the water going?

 

[Berger]

Im guessing that there isnt a big pool of coolant under where you park the car.

So run it on the spot and look for an obvious leak when its up to temperature, it may not have enough pressure to leak from cold, but when warm it will, or take it to a new garage.

 

[Jamous]

What car?
if it's cold out like at night the exhaust gases condense and can look excessive. There may be reidual exhaust gasses in to coolant system from a previous problem or it may well be a gasket issue, lumpy idle points to this as well.
A pressure test with the engine off doesn't always show a leaky gasket, sometimes it only shows up when the engine is running due to cylinder pressure forcing gas into the cooling system, way more than the 15 or so psi a coolant tester puts in.
The coolant is going somewhere, so it's either going into the cylinders or it's leaking, have a good look around it.

 

[SiD the Turtle]

Thanks for the advice so far guys, it's a mark 2 Clio. It's getting on for 10 years old now, but until this problem it's been a good little runner.

I have been running it in the drive way, but to be honest not long enough to get the temperatures up. Sounds like a plan.

The coolant is going somewhere, so it's either going into the cylinders or it's leaking, have a good look around it.

Now this is what I don't get, if water was getting into the cylinders wouldn't it an epic-ly rough ride or not start at all?

 

[paddy]

Now this is what I don't get, if water was getting into the cylinders wouldn't it an epic-ly rough ride or not start at all?

You said in the first post that the idle is a bit rough, you don't need much water leaking to loose a lot:
If only 0.01ml (0.00001L) of water leaks into 2 cylinders while the engine idles at 1200rpm for 15mins that's 0.36L of water lost. Driving at 4000rpm it looses 1.2L

 

[VirtualAdept]

Sounds a bit head gaskety to me... when it was going in my mondeo I had epic clouds of steam when pulling away, water just disappeared and the ph type test thingy showed there was... fuel in the radiator I think... something like that.
Ask your garage to do a block test.

EDIT:: Rereading your post, it sounds like they've checked for that... I'm out of ideas.

 

[Fido McNasty]

Where is the water going?

I think head gasget or cracked head too maybe. What it sounds like at first.
Is your carpet dry?
Maybe the heater matrix?

 

[ShakenNstirred]

i`d say it leaking in to a bore or 2 for whatever reason(HGF or crack)

 

[Lum]

I say head gasket. I've just been through the exact same thing with my Volvo. It too passed a pressure test at the garage who said it was fine.

If you take the cap off the expansion tank the day after a run, does any air rush out?

 

[thecremeegg]

Head gasket mate, definately. My mk2 clio is in the garage with that very issue and I had the same lumpy idle. Temperature rose suddenly and all my coolant was gone

 

[Penance]

Sound like head gasket to me also, when mine went on my Elise I never had any bad looking oil (mayo) but I did have exhaust gases in the cooling system.

One way to check is go drive the car, let it warm up then park it up and wait for the engine to completely cool down. Now remove the header tank cap and if the coolant spews out then there are exhaust gases in the cooling system AKA Head gasket or something worse. If no water comes out then it's probably a leak or something.

Hope this helps

 

[SiD the Turtle]

Thanks for all of the advice guys, I'm going to do some more investigation at the weekend but your experiences with head gasket failure seem to be matching my symptoms.

What should I be expecting to pay for this? Mr AA suggested as I had caught it early he reckoned it was unlikely there was any serious damage or warping, but the quotes from the various garages around here were £175, £300 and £700

 

[Macabre]

Thanks for all of the advice guys, I'm going to do some more investigation at the weekend but your experiences with head gasket failure seem to be matching my symptoms.

What should I be expecting to pay for this? Mr AA suggested as I had caught it early he reckoned it was unlikely there was any serious damage or warping, but the quotes from the various garages around here were £175, £300 and £700

Tbh it's not the parts your paying for really, parts are relativley cheap, it's the labour, since it involves taking the whole engine out, but imo if your going to end up paying hundreds take a look at if it's really worth it keeping that car? it's getting on, and possibly likely to end up with more problems. I had this issue on my pug 306, it had 90 on the clock was about 9 years old, head gasket went so just sold it off no reserve in the auctions for £350.

If your a mechanic or know what your doing and can fix it yourself then it's all fine, but otherwise i'd consider getting rid of the car.

 

[floatindolphin]

headgasket by the sounds of it

 

[Vonsteve]

£175 seems a nice price to me!! Probably doesnt involve getting a new cambelt or anything though.

 

[SiD the Turtle]

Tbh it's not the parts your paying for really, parts are relativley cheap, it's the labour, since it involves taking the whole engine out, but imo if your going to end up paying hundreds take a look at if it's really worth it keeping that car? it's getting on, and possibly likely to end up with more problems. I had this issue on my pug 306, it had 90 on the clock was about 9 years old, head gasket went so just sold it off no reserve in the auctions for £350.

If your a mechanic or know what your doing and can fix it yourself then it's all fine, but otherwise i'd consider getting rid of the car.

You're right, it's done nearly 93000 miles but I can't afford to replace it at the moment.

My dad reckons he can do it as he's done it on his cars in the past (I on the other hand know little), but he's getting on and I'd rather not have him stuck under the car!

 

[SiD the Turtle]

Ha! Phoned the garage (who quoted £175) this morning to ask them to do it, now the price is £600.

Looks like I'll be attacking this myself at the weekend.

 

[mattyprice4004]

Ha! Phoned the garage (who quoted £175) this morning to ask them to do it, now the price is £600.

Looks like I'll be attacking this myself at the weekend.

He's a real man!

Easy enough if you're methodical and have a Haynes.

 

[floatindolphin]

can he get the head skimmed if needed?

 

[SiD the Turtle]

He's a real man!

Easy enough if you're methodical and have a Haynes.

Yup I've had a look at the trust Haynes. It doesn't look too hard, just time consuming.

can he get the head skimmed if needed?

I'm hoping that when I take it apart it won't need it, otherwise I know someone that can do it. Might be a challenge getting the car there mind