What are these metal lines?


Okay, I already feel like a dumb ass but here it goes... I have an 85 GN that I just finished up and fired the motor yesterday. The car runs great! I looked under the car and saw some black substance dripping from the car. It is not coming from any of the seals in the motor or the oil pan gakset. It seems to be coming from these lines. There are two metal lines that are the same size that I have no idea what they are. The other line is smaller and I am sure it is a brake line. The "substance" did not start leaking until I started the car. What are these lines and are they under a large amount of pressure that I couled not cut them and use rubber line? Please let me know.....



Sorry, more info

Sorry, I forgot to write that these line are located between the oil pan and the frame. They lay right on the oil pan cross member.



I would go under the car and see.

Use the finger test. If it's gas it's a fuel return line and rubber high pressure hose could be used if properly installed.

If brake fluid you can also tell by feel and smell and obviously new hard line needs to be installed.
I know it is not fuel because It didnt smell like fuel..... It didnt take my paint off of my frame I just sprayed so I dont think it is brake fluid.....

The fluid did not smell like brake fluid or fuel.... it almost looked like bad oil... I will check to see if it was one of those lines. I should be able to put rubber line to connect those if one is leaking right? Both are low pressure....


mine only has one line going across under the motor to the right front brake

are you sure its not coming from a tranny line beside the oil pan ??

nothing else in that area should have pressure except for when you hit the brakes of course
No, I have three line going across there.... One is the brake line (3/16" line), and two (each either 1/4" or 5/16" line) All are laying right on the crossmember.

did you find out what it was, i thought they were fuel lines, maybe theres a leak and it just looks like its coming from there,

how is the car coming, ive been waiting to see some post and some times, did you do any motor work to it. headers or turbo.

hope you still like it and its not driving you crazy. A week later i kicked my self in the a-- for selling it just like i said i would do. I traded my trans am for a 86 gn and now iam trade my 86 for a rx7 with a gn motor this sunday.

i just cant stay away for these motors now.lol
Car is coming out good! Motor is pretty much completed. I am running a T63e turbo on it now and replaced pretty much every bolt-on component there is. New flowmaster exhaust, headers, etc. I will send some pics in the next few days of the motor work done. Still havent found the leak yet. I am not thinking it might be brake fluid but I need to look.... just too busy these past couple weeks. I did start up the car and it sounds real mean now... turbo spools up nice as well. Will keep you posted!

Question for you Crazy GN

Hey Chris,

I got a question for you. Was there a reason you were not running a MAP sensor on this car? I just noticed that there is not one on there. The plug is there but no vaccum line or anything. Let me know.


the map sensor is only for the boost gauge lights on the dash i think , so i didnt run it. i tried to keep as little vac line as i had to. Cant wait to see the car sounds like you have put some time in it.

talk later gotta go to work

Ok guys,

Here is goes!

I am a big dumb ***!!!! :p I found where my leak was coming from. Heres the story for all you fans in suspense...

It was dring me nuts last night wondering what the hell was leaking... I finally went out to my garage, started the car (sounds mean with no tail pipes) and let the fluid fly! I shut the car off and climbed under to inspect. Here comes the fluid again! I am now under the car checking all the lines by my K-member, oil pan, everything.

I happen to look up near my positive battery cable going to the starter and I see some "wet" spots. After looking closer, seeing the problem, and then kicking my own ***, I grab an 12mm wrench and tighten the turbo oil line fitting coming out of my oil pressure housing in the block! That is where my big "mysterious" leak was coming from!

The oil was dripping down from there, running onto my K-member and running right down to the floor making it look like one of those line were leaking!;)

Anyways, I thank you for all your input and for those who are intrested in some pictures of the finished motor, how do I post them for everyone to see? Let me know.


Clean it up a bit for the bottom motor pics. :p

Glad you found the problem, and thanks for posting the solution, too few people actually do that.