I am looking for some assistance in regards to my car coolant issue.

 

Recently I had a coolant leak into my passenger side of my car and had to get a new heater matrix installed. When I collected the car the person who done the repair told me to keep an eye on the coolant level for next couple of days as he hoped to be able get more coolant as he reckons he managed to get 3l in, got car back on Tuesday.

 

I had check my levels on the Wednesday and Thursday mornings they seemed to be fine, however, on Thursday night I went out to get some shopping and my check coolant light went back on and the tank was empty when I pulled over to check. My coolant temperature gauge went over the 90 mark but did not head into the red. Got my car towed back to the garage who checked it the next day and the mechanic was honest and told me that he didn't fully connect the hose that connected to radiator properly after he drained the car of coolant during the matrix fitting.

 

He rectified the problem and filled the car up with more coolant and dropped it off at my work, which is only a minute away for the garage. When I finished 4 hours after receiving the keys I got into my car turned the engine everything was fine until just after taking off my coolant light came back on, check the coolant tank and it was empty again. There no signs of leak in passenger footwell and smoke either.

 

Like the car worked fine when I got it back from matrix repair on Tuesday, Wednesday and Thursday morning even driven it 100 miles on Wednesday. So I am completely baffled, I have left my car with the mechanic to check over on Monday but I am hoping the isn't anything serious.

 

Does anyone know what might be the issue here?

Edited 16 June, 20241 yr by SMCKIE1993

Hi, welcome,

 

Most probably there was either another leak, or he's left a leak or another leak and/or he didn't refill the system correctly.  It depends where he drained from, 3 litres would be nowhere near enough for a full drain down and refill.  With a 2015 car you might as well drain out as much existing coolant as possible so that it can be replaced with as much fresh new coolant as possible/practical.  Depending on your engine he's supposed to refill the coolant under pressure to get it full first time otherwise it might get an airlock.

 

Once the expansion tank is empty it's difficult to guess how much coolant is actually left in the systems and how much might be required to fill it without taking hoses off to see and guess.

 

Even without a pressure fill it's not difficult to refill just takes time, patience, coolant and the engine running.

 

If you have an actual gauge with needle (rather than digital/virtual) then this is designed to bias to a rock steady 90c even if the actual coolant temperature is an amount above and below this so if you have the oil temperature showing this will confirm if the engine is getting a hotter, but the red section of the coolant gauge means hot not overheating necessarily.

 

You want the heater set to hot to make sure coolant gets in there.

 

HTH.

 

ETA: - P.S. doesn't matter now but you have posted in the 'Diagnostics & VCDS' forum which is about VW scan tool issues and less frequently visited than the  'Skoda Octavia Mk III (2013 - 2020)' forum or even perhaps the 'General Maintenance' forum which deals more with these general matters.

 

https://www.briskoda.net/forums/forum/235-skoda-octavia-mk-iii-2013-2020/

 

https://www.briskoda.net/forums/forum/103-general-maintenance/

Edited 17 June, 20241 yr by nta16
ETA:

@SMCKIE1993 Welcome to the forum.

 

What is the car, TSI or TDI and what size engine?

I know there were some radiators on mk2 and possibly early mk3 where there was a crack/poor manufacturing that would open up when hot and dump all the water.

 

I am not saying it is this, but worth checking the leak isn’t coming from the edges of the radiator if you can’t work out what else is going on.

 

Also I’ve moved this to the mi3 area.

Edited 17 June, 20241 yr by cheezemonkhai

You have to remember that Golfs,Octavia's and Leon's normally have their coolant changed under pressure (at the dealers). If you haven't seen any further coolant leaks, it's probably because the system has burped itself.

 

Usually (if you don't have a pressure system for filling), fill up the header tank as far as possible, then start the cat with the cap off (warning.. hot coolant alert). Let the car get up to temperature and wait until it BURPS and then you can put the cap back on. Keep an eye on the header tank, but usually once it's cleared itself, it's fine.

 

Issue is that heater matrix is the highest point of the cooling system. Air get trapped in the matrix, so hence the water pump has to push that air out. Heater on HI, fan on low, let it heat up until the fan comes on. Gentle pinching of the coolant pipes to encourage the air pockets to remove themselves from the system.

5 hours ago, Ootohere said:

@SMCKIE1993 Welcome to the forum.

 

What is the car, TSI or TDI and what size engine?

It is a TDI 1.6 Diesel (Automatic Gearbox)

@SMCKIE1993  Has it had the Timing belt and water pump replaced? 

Air pocket(s) from gravity fill (not using a pressure filler) can take a good while to clear - guess how I know. 😁