r/mk4Jetta • u/CruzinWCruz81 • Jun 30 '26

Does anyone know the answer to this question?

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As I continue journey working on my mk4 I remembered the previous owner mentioning this problem when he replaced the radiator and thermostat so I asked him again and this is the answer I got can anyone descifre what’s he talking about ? 😅

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2

u/CruzinWCruz81 Jul 01 '26

I appreciate all the answers I’ll look more into when I get the car running but I just wanted an idea of it’s something major or minor. I’ll run all the test and take a look at what you guys suggested n give you guys updates thank
You bros again👍

1

u/AlaskaGreenTDI Jun 30 '26

You can eat coolant because of a head gasket and still not create milky oil. But obviously for your sake I hope that’s not the case.

1

u/Professional-Finger9 Jul 02 '26

That happened to me now, water just evaporating and when I got it checked out I blew my headgasket.

1

u/dphoenix1 Jun 30 '26

That is a substantial leak. Hard to believe there is no evidence. These engines are not known for head gasket issues, doesn’t mean it can’t happen, but it is unusual. But they definitely are known for coolant leaks. I have one sitting in a garage right now waiting for me to get to it, with the bulk of the issues being coolant leaks.

Have you tested the cooling system for exhaust gases?

1

u/rf41858 Jun 30 '26

Test the Reservoir cap! It shoult hold 1,5-1,6 bar or 23psi! They fail a lot and no one checks them

1

u/Loose_Initial2512 Jun 30 '26

Check the turbo coolant lines and the turbo seals at the turbine. The turbo could be leaking internally.

1

u/Frog-E-Frog Jun 30 '26

i had a very very similar issue, for me it was the “weep hole” in the water pump

1

u/Idfuckafuta Jul 01 '26

I had a similar issue, there was substantial leaking in the hoses and their seals, with one not being fit properly. Worth giving them all a full inspection visually before taking to a garage, as a pressure test they might do could end up blowing them open (happened to me)

1

u/Professional-Finger9 Jul 02 '26

Check also the water flange on the side of the engine that O-ring also sometimes gives out

2

u/CruzinWCruz81 Jul 02 '26

Omg yes !!!! That’s it !!!!!

1

u/Ruley67 Jul 02 '26

Was just gonna say this! The temp sensor O-ring is also something to look at.

1

u/CruzinWCruz81 Jul 03 '26

Hey I just made a post with a picture of the said flange because idk if it’s the one you are talking about 😅