Coolant disappearing trick?

**Asharp27** · 07-01-2008 11:10 PM

ok so i just installed my boost gauge and i removed the line going into the top of the coolant tank so i had better access to the vacuum line and whatnot. anyways i had also loosened the cap and towards the end we were loosing daylight so we kinda had to rush things so we finished up and i drove home with the coolant cap unscrewed a bit which isn't good obviously but my question is where did all my coolant go? i stopped about half way home (b/c my coolant light had gone off) and realized i had forgot to close the cap so i tightened it down and drove home. I filled it back up almost like two liters worth and it gulped it down to (somewhere?) which i didn't realized till i had gotten to work so after i got home i filled it up again and it seemed to swallow up some MORE of it but it finally seems to be keeping a steady amount of coolant in the tank although i'm way below the min. line and need to go get more(speaking of which, what type of coolant do i need?) excuse my stupidity. Thanks for anyone who can shed light onto this topic

**AudiA4_20T** · 07-01-2008 11:35 PM

you need G12 coolant from Audi/VW... its red and expensive but can be had for cheap at Napa or random online places...

Now, as for your coolant dissapearing, if its not steaming out everywhere in the engine bay because the cap is not sealing, then your oil cooler is busted

**Asharp27** · 07-02-2008 12:04 AM

G12, thank you!

an its def. not steaming out anywhere lol and not leaking out either. oil cooler; how much is that going to run me?

**AudiA4_20T** · 07-02-2008 12:22 AM

Originally Posted by Asharp27

G12, thank you!

an its def. not steaming out anywhere lol and not leaking out either. oil cooler; how much is that going to run me?

$100 and an oil/coolant flush... I did a writeup for it, its in the DIY forum

**diagnosticator** · 07-02-2008 07:12 AM

One explanation; The loose cap allowed the coolant to overflow from the tank, then air became trapped in the cooling system. The trapped air is purging out so additional coolant is needed to top up until all the air is expelled.

**Asharp27** · 07-02-2008 11:08 AM

hmm, well i really hope that is the case haha! but i will def. check your diy A4_20T

what is the ratio on the coolant / distilled water? 50/50?

**CO AVANT** · 07-02-2008 01:05 PM

50/50 is typical. Water has better cooling properties over coolant so if you want your engine to run cooler run more water ratio. If your not in a freezing climate you truely only need enough G12 to lubricate the seals. You can run as low as 10% G12 for that. I run 80% water, 5% purple ice, 15% G12 and I never have problems with freezing in the Colorado winters. You don't even have to worry about freezing in TX. Use distilled water BTW.

**Asharp27** · 07-02-2008 01:09 PM

ok thanks man! whats that purple ice stuff you talk about?

**CO AVANT** · 07-02-2008 01:28 PM

It's like water wetter but much better. Royal Purple makes it.

"Purple Ice is a high performance, synthetic, radiator coolant additive. It reduces engine heat by reducing the surface tension of the radiator fluids for improved heat transfer.

Purple Ice also helps to prevent the formation of scale deposits in the radiator for optimum coolant flow, and it lubricates the water pump seals"

It also mixes with G12 much better than Redline's water wetter. I have done stress heating tests to prove this.