High Pressured Blow Off Sound and Oil?

[Beowulf]

High Pressured Blow Off Sound and Oil?

After driving around in the mountains for a few hours I came to the intersection of a major road. Upon waiting for traffic, I gave the jeep gas for a normal take off. I immediately heard a sound that was similar to a High Pressure Blow Off valve that seemed to come from the driver’s side. It only lasted for a seconds. I may have just been paranoid, but it seemed to have some overall vibration coming through the seat. Even my wife thought so, but the steering wheel was completely vibration free. Since it seemed normal enough I drove the remaining 5 miles home. Once home I walked around the jeep and did not see anything. However, once I crawled under the jeep I noticed a viscous liquid on the Driver side motor mount. It was coating most of the motor mount and really nothing else I could see. The liquid is similar to brake fluid, but not quite, and not quite motor oil. If I had to lean one way or another I’d say brake fluid.

There was no liquid on the engine block itself and I could not find any liquid on the Power Steering or brake lines? This is basically right under the air intake.

I checked the fluids in everything and it seems within specs and had not moved since the last time I checked. At this point I am at a total loss, but am worried something major is in the works.

Any thoughts will be appreciated.

 

[Root Moose]

There is such a thing as a liquid filled motor mount... but I'd be surprised to hear they were ever used in Jeeps.

 

[Beowulf]

I'm pretty sure the jeep did not come with Liquid filled motor motor mounts.

 

[AZBrad]

AC line? I just had one burst and it deposited an oily residue that may fit your description. If you weren't running the AC at the time you wouldn't notice anything out of the ordinary at the time. Hope this helps.
Brad

 

[Beowulf]

I did have the A/C on. Would an oil like brake fluid come out of the A/C line. It is definitely like someone spilled some brake fluid, not a coating like a fine spray misting?

 

[Root Moose]

Yes, A/C oil is kinda like brake fluid at a glance.

 

[AZBrad]

Hard to say without seeing it of course, but in my experience the refrigerant has oil in it that leaves a residue but maybe not quite as thick as brake fluid. Assuming the level in your master cylinder looks good, I would idle with the AC on and see if it stops blowing cold in a few mins.
Theres only a couple things under there that it could really be, and sounding like a high pressure blow off matches up with an AC line/condenser rupture pretty well.

 

[Beowulf]

So if I have lost some oil from the A/C, how do you replace what has been lost?

 

[Root Moose]

When I replaced the compressor on my XJ I poured the required amount in the drier.

Is your system still pressurised? That hissing noise....

Makes me think you have no pressure in your system. I'd be inclined look at the lines and fittings a little further to see where you are leaking.

If the system has a hole it must be fixed first (of course).

 

[JAFJO]

Weird, some guy over here had the same issue.... :wings:

http://www.jeepsunlimited.com/forums/showthread.php?t=505222

Sounds like a good explaination.

 

[Beowulf]

JAFJO,

Funny how that happens. He even has the same forum name?

Yeah Chris142 over there really seems to know his stuff. Also Doctor D over on ROF mentioned the same thing. I think between those two they have like 5 centuries of automotive knowledge.

Now I just need to figure out what really caused the Pressure Spike. So far the fan seems fine and the Engine temp has not moved at all.

Of course I am under warranty so I could take it in.