Hey guys, so over the last couple of days, my car has sprung a leak. 
It appears to be coolant, and coming from the back of the motor. Is this a common place for a coolant leak?
When I put it up on my lift tonight, what should I check for? Certain fittings or hoses?
Figured this is the best place to ask, since most of you are Albert Einstein proteges.
Thanks in advance guys! ;D
On the S4, there is one coolant hose that connects to a hard line that has a T on the back side of the motor (probably not on an 4cyl as there’d only be 1 engine bank). I don’t know how well you can see that, but it’s A PAIN to get to if that’s the case, but I doubt it’s the cause. I would check the expansion tank, especially the bottom side. I know that’s been a cause for leaks in other models. From there I think you’re just gonna have to poke around some. Best of luck.
Thanks maddog, I’ll definitely check those areas out!
weird, theres another 3.0 guy on AZ with the same problem. knock on wood. Good luck!
Could be one of the orings or gaskets on the main coolant pipe. If it was leaking there I think it would appear to come from the back of the engine since it connects the thermostat, water pump, and cylinder heads. Put some coolant dye in there and use a uv light to help you find the leak.
Here’s a view of the uninstalled pipe:
http://i.imgur.com/dufVN.jpg
the coolant leaks I’ve seen most commonly revolve around the coolant reservoir on older (5+ years) cars developing cracks which cause a slow leak.
I’d advocate changing it out for a new one (like $25) if your car is 5 years old (irrespective of what this particular leak is from…I just mean for everyone. It’s a good piece of preventative maintenance)
One of the first things I did when I got my car… Also might be a good time for a coolant flush if that hasn’t been done recently!
meistah- just saw that too… seems to always be more then 1 person having similar issues at a time 
komesh- thanks for the heads up! I looked around there, but couldn’t exactly determine if that was the culprit. Where would I be able to pick up some coolant dye?
saki- I am actually going to change out the expansion tank, as well as flush the fluid. It appears it might have just a minor crack in the seem, as I see some evidence of dried coolant underneath. But nothing major.
When I had the car on the lift, I noticed a line from the back of the reservoir that runs down into the rear of the motor. Kind of what maddog was getting at. When I look up at that, I notice some shiny, what appears to be coolant. But I can not access it to really for sure. Here is what I believe to be is the hose-
http://img684.imageshack.us/img684/4459/coolant.png
Uploaded with ImageShack.us
Also this morning, my jeep developed a coolant leak as well So went to diagnose that, found a broken radiator. Ugh, got a nice warm shower of coolant to start the day off tho! Haha. Off to 4 wheels parts I go!
autozone should have coolant dye, not sure about the uv light but probably so. it will make the process of pinpointing the leak much easier.
I’m glad there are so many high mileage cars around here, lets me know what to fix before it breaks on mine!
Also, just because you saw coolant on that back line, it’s very possible that a leak in the tank would allow the fluid to travel down the rear line to where you eventually saw it. I’d say knock the tank out first and see if you’re still having issues.
I replaced mine not too long ago, had several cracks that leaked periodically where I would notice.
Replaced it and all is well, hopefully it will be as easy that for you
I just want to hug all of u!
http://www.forumsextreme.com/images/sLo_grouphug3.gif
haha
Thanks for the help guys. Its weird cause the car doesn’t do it all the time, which makes me think its the reservoir.
Zingo- I’m about to do all my vacuum lines. You have inspired me… Well that, and the fact I just touch any electrical wire shrouds, and they just crumble
Haha oh fuck those lines… Just saying, go ahead and get that old shit out of there and save the headache.
Thats sick dude, glad you got the problem worked out. Another story of how awesome AR is.
problem no fixie
came out to my car, puddle underneath. checked everything to see if it was wet. not under the resevoir, or anything on the top half of the motor bay.
komesh- is that tube kind of lower on the motor?
Hmmm, I thought I had a leak near the back of my engine, turned out to be my radiator. pretty hard to track down leaks unless you can physically see damage, even if its dripping it could be coming from somewhere else.
Or you could get one of those uv testers…
Try pulling your bumper and squeeze the plastic sides of your radiator (like push them together), you will see it leak if that’s the problem. The part where the plastic meets the metal can get separated over time, as well as small cracks that are nearly invisible.
Heads up if it is leaking from there it will get worse once you squeeze it.
Ultimately the best bet is a proper leak test. Maybe you could even get a shop to take a look. I had a shop charge me for 1/2 hour to find the leak, then I fixed it myself ;D
Good looking out.
Im headed first thing tomorrow to get a leak tester. Bout to go all CSI on her.
Don’t forget the lab coat and safety glasses…
Good luck with getting it fixed
The main coolant pipe I was talking about sits just above the cylinder heads. You pretty much gotta remove the intake manifold to get a good view of the junctions where the gaskets or orings are.
ah. I was afraid of that. Is that a tough task. Im pretty mechanical, but never have done it on this car. Pretty straight forward?
