Few weeks ago the coolant level was below the minimum so I fill it up with green stuff, then I found out it only works with G12 coolant(I have made a big mistake). After I filled up with green coolant, and maybe drive serval times, the level went down again. So I am wondering is my car having a leak....I have read some posts said that putting coolants other than G12 in Audi they would become gel, also they can not hold up the heat(but my temp seems to be very normal)..so would it be the reason of the coolant level always goes down after putting the green stuff? If so, why my car also had a low coolant level before i put the green coolant in since my car had a entire service/check just few months ago. ( I am in Chicago. Does the cold temperature involve?)

Thanks very much!

 

Do you see any leaks anywhere? What engine do you have? Check the coolant temp sensor housing and see if it's leaking. It's on the back of the block.

Josh

 

I have a 1.8T. Can you tell me more details about where the coolant temp sensor housing locates? Can you tell me some place I need to check?

Thanks very much!

 

temp. sensors for the 1.8t are located right in the middle of the block all the way back right by the firewall. It's kinda hard to see unless you know what you're looking for, but once you see it, you'll know what it is. Chances are, the sensor prolly popped out or is loose. That happened to me and same thing happened. G12 is not the only coolant our cars can use, they don't recommend using other coolants for some reason, but I've used other coolants and everything is okay. I've heard that if they mix it will gel and mess stuff up, but with using blue or red or green or whatever straight and not mixing should be okay. If you need any help, ask someone for some pictures.

 

My car had the same problem. Collant sensors are on the collant flange (a notorious part for failing). Its a black plasic pipe that bolts on directly to the head. The other end goes to the coolant resevour. Just follow the lines from that to the back of the head. If you cant find that look on the top of the transmission and see if you see a pinksih residue. If so thats probably the problem. http://www.audiworld.com/tech/eng76.shtml

 

The sensor seems to be fine. And I just found out some cables under the expension coolant tank have some green coolant(see pictures).
Since I have mixed the original G12 with green coolant, the coolant in the transparent expension tank is neither green or pink, it has no color. How come coolant on the cables is green? Would it be possible that since I have accidently spill some green stuff out when I refill it. But it was a such long time ago(the coolant could remain liquid on the cables for few weeks?)...

Does anyone know what is the problem?

Thanks very much!

 

its not the best but yes you can run strait green - IF - you flush the system completely first with water to get any of the old pink stuff out. and the only valid reason for running prestone instead of G12 would be if you have a heavily modified car and are constantly doing engine work that requires you to dump the coolant. G12 can get expensive if you have to replace it monthly. however if you have to replace it once, fill it with the correct fluid.

mixing the green in with the pink probably didnt cause a leak, but its still not good to have in there. the leak could be coming from a number of places but heres what the part they were talking about looks like.... (one of the two holes on the top has a sensor in it, the other has a plastic plug)

 

I'm having a similar problem, can anyone verify the location of the flange and sensor on the 2.8? is it right on the back of the block like the 1.8 or is it located elsewhere? thanks

 

Those pictures you posted seem to show the area right underneath the overflow, which would be wet if you splashed the coolant around while adding it to the reservoir. It is also where it comes out if it gets hot and overflows. If you havent been overheating, then it is probably just there from splashing it around the rim while you are filling it up.

 

I dont have overheat yet, but the coolant level always drops.