View Full Version : Help Loosing coolant and water

06-27-2015, 11:06 PM
so i have an issue with my car that has recently started but im going to lay the ground work to remove a bunch of issues it may be.

B5 A4 1.8t APR stage 1 tune automatic with a forge BOV SPLITTR.

I had a small leak from my coolant flange and thermostat housing both of these items have been replaced and redone no leaks there anymore. now that i have no leaks i notivced i would still lose coolant on my way to work, have to put in some water into the car since the warning light came on, not coolantant(its expensive) to get to work and refill the car. after this has been happening for about a month i put the car up on a lift and ran it while it was 6 feet off the ground to see what was going on.
I brought it to operating temperature, oil was around 210-220 degrees and and the water temp gauge was directly in the middle of the gauge. I held constant of about 2000 RPMM to get it to temperature, let off the gas no problem.

I then swept my rev range up to 5000RPM held for 3 seconds and then let off. about 4-5 seconds after i let off the gas and let it idle a bunch of water came out the overflow portion of the expansion tank, a very considerable amount. i went down the rev range and found that if i revved it up to 3000RPM it would do te same result as if it was 5000 RPM.nothing happens at lower RPMS.

So this is how i lose all my coolant/water. i have checked to see if it smells like exhaust through the expansion tank, it does not, i used a color changing liquid to see if any exhaust gas was coming through, nothing. i checked and replaced the thermostant, , none of these are the issue, oil is not milky.

Tried to rule out all possible things. like a head gasket or something relating directtly to the engine. it doesnt seem to be anything like this. also the headgasket and head were recently redone about 2000 miles prior with no issues. i only got issues when i developed a leaky rear coolant head flange. at this point i dont know if i have something clogged or if my expansion tank is broken or something else. any help would be greatly apreciated thanks in advance!

06-29-2015, 09:23 PM
I'm having the same issue with my B6 3.0L A4 did you ever find a solution ?

06-29-2015, 09:34 PM
I refuse to read OP due to lack of paragraphs.

Please, do you audience a favor and use the enter key at periodically significant intervals.

06-30-2015, 07:42 PM
well i did a full coolant flush and rfeplaced the o ring in the coolant tank cap. then i when and bought 3 bottles of pentofrost E and mixed it all 50/50 with water. filled the car up with it as needed and rebottled the rest i didnt use, it used about 2 full bottles of g13 concentrate maybe 1.5-1.75 bottles. ran the car with the new coolant and no problems.

so the issue here is that the water boils at too low of a temperature 212F. our cars run normally at 208.4 F. 50/50 g13 boils at 224F it no longer builds up enough pressure from being only water and stays liquid as its mixture. thats what worked for me so far.

07-01-2015, 12:31 AM
Cooling system pressure test. If all checks out with no leaks, I would definetly check for steam from tailpipe. Worst case scenario, you're burning it. Good luck

07-01-2015, 09:46 AM
thanks for the help, so with coolant 50/50 mixed in so far i have not see any leaks after making it home from work. a little drip from the overflow from the expansion tank is all maybe like 6 droplets max. tank is at max line for collant still so thats good right.

anyways i shut the car off and listen to the system i hear a bubbly air noise coming from the turbo coolant line to the top large water pipe. is that normal im going to do the pressure test to see what else is going on.

now if possible i am burning it wouldnt i see white smoke out the exhaust.

07-01-2015, 10:02 AM
it could also be your cap is no longer holding the correct pressure, this exact thing happened to me until i replaced my cap.

07-01-2015, 10:10 AM
i think the cap might be ok i just replaced the o-ring on it the other day, my expansion tank is a little beat up though, i may just replace that whole part since its pretty ugly. thanks for the suggestion though.

07-03-2015, 06:59 PM
Thank you for the idea on pressure testing the system, turns out my tank was junk, got a different tank and reused my cap and holds pressure perfectly now. I would have never guess on the pressure test so thank you again.