Engine coolant vanishing and overheating light

losing_my_coolant

Hello, I'm hoping to get some help with a car problem I have from you very helpful people please.

I have a 10 plate Kia Venga, a couple of weeks ago the overheating light/or coolant light? was coming on its a picture of water with a thermometer in red. So I checked the coolant and there was plenty. It did the same the next day and the coolant was mostly gone, so I topped it up and no problems.

Whilst reading up on the likely cause, a website mentioned that if you ovefill the coolant, modern cars will tend to blow it out the exhaust. I figured this was the likely cause as I was filling to the F line (I now know to fill it half way between L and F) so I filled it half way between L and F and hundreds of miles later and no recurrance, have been regularly checking collant level and all fine.

Two days ago I did a 200 mile round trip no problem, no loss of collant or warning light.

However yesterday I did a 32 mile journey and during the last couple of miles the light came on. When I got to my destination, I checked the coolant and it was all there. I carried onto the next leg of the trip, a 14 mile journey, no light, but when I got there, all my coolant had vanished.

So I filled it up with water (all I had to hand) and drove the 50 or so miles home, I get home, all the water I put in the coolant tank is gone.

So I'm guessing the obvious one is a lea, although I'm wondering why its an intermittent loss.

A few notes:

-Car has an LPG conversion if it makes any odds (don't know if it makes the engine run hotter)
-Car is under warranty and it went in last week for a problem with the locking, I mentioned coolant problem to the service advisor who said if they looked and it wasn't covered by warranty it would be a £120 diagnostic charge, as I found out out the blowing out the exhasut thing before it went in, I told them not to bother looking as I thought it was sorted and I'd rather shell £120 towards getting it fixed if its out of warranty rather than to tell me whats wrong
-When I got the work docket back it mentioned "unable to fault problem with coolant light", as I wasn't in and they posted keys, I don't know if this means, couldn't find a problem or didn't look.

So I'm going to ring the garage tomorrow to find out what they meant (it has to go back in again to fit a lock latch soon).

Does anyone think I should pursue under warranty or try my luck with a local indie? My level of knowledge/ability with cars ends at lifting the bonnet and checking fluid levels so DIY prob out of question ( I might be able to buy BIL a few beers as he knows and does a fair bit with cars but he is a distance away and I'm hoping to get this sorted soonest as I'm worried about engine damage)

Thank you very much for reading this far! Any help/ideas appreciated.

[Deleted User]

Check your oil level and report back.

losing_my_coolant

Bedsit_Bob wrote: »

Check your oil level and report back.

Thanks Bob, just check and engine oil is full (now I might be talking about nothing, but it was a couple of millimeters over the full dint on the dip stick) it was serviced in May.

Jamie_Carter

Have a look on the underside of the oil filler cap. Is there any white grease, that looks a bit like mayonaise?

DUTR

Not sure why it would not be covered by the warranty, it does sound to me like the heater matrixx maybe leaking

Jamie_Carter

DUTR wrote: »

Not sure why it would not be covered by the warranty, it does sound to me like the heater matrixx maybe leaking

One way to tell if the matrix is leaking, is if you can smell steam in the car when the heater is on. You may also notice the windscreen steaming up far more than you would expect.

[Deleted User]

So, is the oil level higher than it was, the last time you checked it?

losing_my_coolant

Jamie_Carter wrote: »

Have a look on the underside of the oil filler cap. Is there any white grease, that looks a bit like mayonaise?

Thanks Jamie, there is no sign of any 'mayonaise' underside the cap and as far as I can see into the oil tank (correct term?) looks to be clean and free of any residue.

DUTR

Jamie_Carter wrote: »

One way to tell if the matrix is leaking, is if you can smell steam in the car when the heater is on. You may also notice the windscreen steaming up far more than you would expect.

I agree especially if it was winter, I had Golfs with leaky matrices that showed obvious symptoms, but my Corrado, showed nothing other than loosing coolant, it was only after I sold it, some months later the new owner informed me that the matrix had failed

losing_my_coolant

DUTR wrote: »

Not sure why it would not be covered by the warranty, it does sound to me like the heater matrixx maybe leaking

Thanks DUTR, It was the way the service advisor talked about the diagnostic charge, it didn't really inspire confidence, that and KIA weren't overly happy about the LPG conversion. Is the heater matrix a big job and is it best to not drive until diagnosed do you think?

losing_my_coolant

Bedsit_Bob wrote: »

So, is the oil level higher than it was, the last time you checked it?

Bob, I would say it was the same as the last time I checked, the oil is a syrup kind of colour, a colleague mentioned checking if the oil appeared to be contaminated.