Losing Coolant - No Leaks

[Leon2016]

Hi,

I have a SEAT Leon Mk3 2016. It seems to be suffering with loss of coolant but with no obvious leaks in the engine bay.

It first occurred last November, then recently at the beginning of June and then a week later. The coolant temp never goes over 90 so it doesn't seem to be boiling over. I last filled it a month ago and it's now already well below MIN.

There are no obvious leaks within the engine bay, there's no milky residue on top of the oil cap so I'm at a bit of a miss where this coolant is coming from.

Had anyone else had a similar issue that can help?


Thanks in advance

 

[rdraheim]

Hi,

I have a SEAT Leon Mk3 2016. It seems to be suffering with loss of coolant but with no obvious leaks in the engine bay.

It first occurred last November, then recently at the beginning of June and then a week later. The coolant temp never goes over 90 so it doesn't seem to be boiling over. I last filled it a month ago and it's now already well below MIN.

There are no obvious leaks within the engine bay, there's no milky residue on top of the oil cap so I'm at a bit of a miss where this coolant is coming from.

Had anyone else had a similar issue that can help?


Thanks in advance

I just bought a 2015 Mk3 with a 1.2 TSI.

These EA211/EA888 seem to go through thermostat housings/belts/water pumps and it might be hard to detect the leakage as it's under a lot of stuff.

The engine I bought is meticulous and it would show up somewhat easily.

What this video and have a look at this part of the engine and look for any traces of coolant ... I haven't filled the coolant since buying it, but I'd imagine you're looking at 100-200ml of coolant at least, which should leave a good sized puddle/drip/trace.

This is an excellent video of where to look in the engine bay for massive leakage.

more rare, but you could have leaking from the charge cooler into the intake manifold ... but I'd start with the video.

 

[SteveGSXR600K1]

What engine does it have? Might help narrow possible causes.

 

[Leon2016]

What engine does it have? Might help narrow possible causes.

It's a 1.2 TSI

 

[rdraheim]

It's a 1.2 TSI

Honestly, in that case, I would start with that thermostat housing if you can access it with a light and mirror.

How are you sure there are no leaks? Were you under the car?

 

[Leon2016]

Honestly, in that case, I would start with that thermostat housing if you can access it with a light and mirror.

How are you sure there are no leaks? Were you under the car?

There are no obvious leaks from looking in the engine bay. I'm going to get it jacked up at the weekend and take the under tray off to inspect further.

I'm just trying to get a gauge of whether anyone has had similar issues or there's a common fault that I can inspect straight away.

 

[rdraheim]

There are no obvious leaks from looking in the engine bay. I'm going to get it jacked up at the weekend and take the under tray off to inspect further.

I'm just trying to get a gauge of whether anyone has had similar issues or there's a common fault that I can inspect straight away.

Please let us know. My money is on the thermostat housing but am curious about other fault modes. The engine under tray is likely hiding most leak, I would guess.

 

[Leon2016]

Please let us know. My money is on the thermostat housing but am curious about other fault modes. The engine under tray is likely hiding most leak, I would guess.

On further inspection this morning it looks like there appears to be fresh liquid on top of the gearbox. I've attached photos, is anyone able to pinpoint where this could be coming from?

 

[rdraheim]

Hi!

That's from the thermostat housing that I posted in the previous video. You can see the coolant sitting on the gearbox at the beginning of this video.

Here's another video:

usually that means that the thermostat housing itself has overheated and warped and is allowing coolant to drip on to the gearbox.

the only way to fix it would be changing the system (housing, pump, and belt).

you can continue to refill, but if the housing is warped or the seal is bad, it will simply continue to leak until complete failure.

 

[Leon2016]

I've managed to get it jacked up today and it looks to be the turbo, oil and coolant leak.

Is this a common issues, does anyone have a rough idea of cost on this job - I imagine a good proportion will be labour?