Hi everyone 

Ive bought an 2015 octavia diesel estate 

had for two months

warning light flashing up check coolant

each time drive is very different 

can do 20-30 miles and empty

can drive 200miles plus then empty 
never empty day after filled up 

check every other day

no signs leaking

just vanishes and warning light

any others with same issues .

thanks

Ps my first time on here . 

It's obviously leaking when hot and pressurised.  check all around the engine and underneath when the engine is fully warmed up and with the engine running.  Could be a loose hose or a defective cap on the header tank.  If not go to a local garage and ask them to do a pressure test.  You may wreck the engine if you don't fix it soon.

Good evening Farty

had coolant bottle and engine in two weeks ago for pressuring test

had car full day 

found leak from bottle to a hose 

fixed but two weeks laster back in same boat situation-took back to garage Just and cleaned bottles dried and topped up and sent on my way .

cant find where why leaking ,

thanks .

ps how will wreck engie .

 

If you run out of coolant, a) the temperature gauge will drop and b) the engine will seize.  That means you would needs new engine.

Farty 

thanks for that

car came with 6 months warranty 
And 4 months left ,

should the garage repair and or investigate this issue of the mystery of the vanishing coolant liquid . 

Your garage sounds crap. They've pressure tested. They should do a sniff test to test for hydrocarbons (testing for head gasket failure) and they could put a dye in the coolant to help them find leaks. All the stuff I'd do at home and I'm not a mechanic!

 

Probably your water pump is failing. Its reasonably common on the diesel aparently. Mine is due to be replaced with the timing belt next month as mine is also a 2015 and the timing belt is due after 5 years, so do the pump at the same time. Make sure you get the timing belt done if it hasn't been and if it has been, ask if the coolant pump was changed to rule that out.

Edited 18 September, 20205 yr by NikTheGeek

Doesn't that give the garage an 'out'?  I think OP should get the coolant leak fixed under warranty and then go elsewhere for the belt change.

Hi Both thanks 

for the info

can I ask daft question for this car

whats different with Timing Belt and Cam Belt 

 

also what’s OP stand for 

thanks 

3 minutes ago, RockyAmo said:

also what’s OP stand for 

Original post or original poster - he who starrted the thread or the first post.

Timing belt and cam belt are different names for the same thing. (The belt drives the cams and sets their timing)

 

OP is Original post or poster

Edited 19 September, 20205 yr by BJM
Typo

Hi Both thanks again 

much appreciated.

What does the temperature gauge read?  Does it move at all, does it go 'off the scale"?

Temperature gauge when driving always @90 

oul pressure when driving always around 95-100.

 

its mainly warning lights that indicate an issue .

Water pump is the usual suspect in these situations.

Hi there 

I’ve just checked all paperwork that came with car

cam belt 

water pump replaced March this year.

On 19/09/2020 at 18:02, moley said:

Water pump is the usual suspect in these situations.

 

Does it mean coolant is leaking from the water pump? Why does it happen?

If you can't see any coolant under the car I don't think it will be the water pump (which has a seal that might fail).  If you take the header tank cap off when the engine is cold and then start the engine, do you see any bubbles?

Hi farty and lab4games 

car gone back to garage where bought,

ive got curtesy car

fews days ago coolant bottle dropped from mac to min and clearly see leaking from bottom hose and underside of coolant bottle 

parts have been ordered and waiting car parts installed and back to me .

thanks for Keeping in touch 

I

10 hours ago, farty said:

If you can't see any coolant under the car I don't think it will be the water pump (which has a seal that might fail).  If you take the header tank cap off when the engine is cold and then start the engine, do you see any bubbles?

I am driving a 2016 1.6 TDI.

 

I have been losing coolant slowly over 2 months. The low coolant red warning light comes on.

Seems to be hitting below MIN level every few hundred KM.

 

Never had the over heating temperature warning.

 

Pressure test was ok 

 

I don't see any puddle below the car either.

 

Is this typical of the common failing water pump issue?

I took 2 photos of it cold and engine just started.

Edited 26 September, 20205 yr by lab4games

IF there had been a lot of bubbles in the coolant header tank, that would suggest a failed head gasket or possibly a cracked block.  If the water pump seal fails you should see a puddle under the car after it's been parked a while.  It sounds like the OP's situation - a leak that starts when the coolant system pressurises as it gets to normal operating temperature or perhaps when the engine is worked hard and the coolant gets hotter still.  It could be venting as steam but in that case I'd expect the temperature to be above normal ie 100C plus

22 hours ago, farty said:

IF there had been a lot of bubbles in the coolant header tank, that would suggest a failed head gasket or possibly a cracked block.  If the water pump seal fails you should see a puddle under the car after it's been parked a while.  It sounds like the OP's situation - a leak that starts when the coolant system pressurises as it gets to normal operating temperature or perhaps when the engine is worked hard and the coolant gets hotter still.  It could be venting as steam but in that case I'd expect the temperature to be above normal ie 100C plus

So it isn't head gasket issue since no bubbling and the dipstick doesn't show any increase in oil level.

 

When are the conditions that the coolant will leak out from the water pump seal?  Because I realised the car could be used for a period of time with no loss in coolant level.

As the coolant gets hot the pressure rises.  So it may not leak until the temp gauge has reached its normal position.  The leak could be anywhere.  Do you have the car's history?  Has the water pump been changed ever?

 

Yes I have it straight from the factory.

water pump hasn't been changed for 4years/118000KM

I think you need to get the timing belt inspected and do the water pump at the same time since they are close on the engine.  But check with your garage as I don't own that model.  It's 60,000km or every four years!

Edited 28 September, 20205 yr by farty

Managed to locate the leak today after another round of low coolant warning. Took a video.

 

I think is the water pump?

 

 

Sending in to the workship.