Coolant leak, can’t find?

[Jakeokj]

Hi so I have a mk7 Gti and I was idling for about 5 minutes when I got an indication on my dash I have low coolant. I got outside and saw a huge puddle forming underneath the car. I let it sit overnight because it was late and most of the coolant is dried by now. My question is how can I find the source of the leak and what’s the process in putting in more fluid, if I need to getting air out etc. It started very abruptly so it is not a slow leak.

 

[cb1111]

You sure it was coolant and not AC condensation?

Where is your coolant level on the expansion bottle?

 

[Jakeokj]

You sure it was coolant and not AC condensation?

Where is your coolant level on the expansion bottle?

Coolant is completely gone, I’ve jacked the car up. It’s more on the passenger side but the bottom of the oil pan and plastic shield is covered in orange coolant.

 

[cb1111]

Waterpump? What year? How many miles?

 

[Jakeokj]

Waterpump? What year? How many miles?

2016, water pump was replaced at 90k miles currently at 131k and I just had the timing chain and covers replaced 1k ago.

 

[cb1111]

expansion tank cracked? What did you do recently to the car?

 

[Jakeokj]

expansion tank cracked? What did you do recently to the car?

Maybe I haven’t checked that yet haha. I recently switched to E30 gas I’m still on my first tank that’s about it though everything else was done a while ago and has had no issues.

 

[cb1111]

So what kind of mods do you have?

 

[Jakeokj]

So what kind of mods do you have?

Downpipe, intercooler, intake. Just basic bolt ons

 

[JerseyDrew77]

2016, water pump was replaced at 90k miles currently at 131k and I just had the timing chain and covers replaced 1k ago.

Was your thermostat housing replaced with the water pump? If not, then that could be the culprit.

 

[Jakeokj]

Was your thermostat housing replaced with the water pump? If not, then that could be the culprit.

Not sure... I’ve narrowed it down to under the expansion tank. It’s dripping from right in front of the passenger axle off the frame.

 

[jimlloyd40]

Not sure... I’ve narrowed it down to under the expansion tank. It’s dripping from right in front of the passenger axle off the frame.

Is it overflowing the expansion tank and coming out of the drain tube?

 

[Jakeokj]

Is it overflowing the expansion tank and coming out of the drain tube?

Is the drain tube just at the very bottom of the tank? It was not overfilled when it first leaked.

 

[jimlloyd40]

Is the drain tube just at the very bottom of the tank? It was not overfilled when it first leaked.

The drain line runs out the top towards the fender.

 

[Jakeokj]

The drain line runs out the top towards the fender.

That seems to be the only reasonable thing, any reason why it would overflow when I’m idling at a gas station?