So I continue my process of checking my newly purchased 91 S5 N/A, and I came across two unconnected hoses that I have been unable to identify. Any help would be greatly appreciated.

Here is an overview of the locations of the two hoses,


Hose 1 is in front of the radiator on the driver's side,


Hose 2 is next to the throttle body, again on the driver's side,

 

#1, pic is not that great, looks like an AC line?

2. that's the bleeder screw for the clutch slave.

 

#1 also looks A/C related to me. Pull the black plastic covers and take a look in there. The condenser and drier might be gone as well.

#2 is the slave bleeder, as mentioned. It doesn't connect to anything.

 

I took the picture of #1 by pulling open one of the black plastic covers. I'll try pulling all of them out later. I am sure that the A/C drier and compressor is still in the car. It's not very clear from FSM, but I suppose the condenser sits in front of the radiator?

 

Yeah, the condenser would be in front of the radiator and behind the oil cooler.

 

It does (or did) but #1 is definitely the end of your (unconnected) hi pressure AC line, coming from the output of the compressor. Looks like the piping it connects to that would lead into the input of the condenser is missing, so who knows if the condenser is there.

The receiver dryer will be in the comparable position on the opposite side of the car (passenger side).

#2 is the clutch bleed--supposed to be there, only hook a hose up to it if you are bleeding the hydraulic clutch.

 

I see. I probably want to jack up the car and take a closer look then. I also just found out that the car has a S4 radiator. I suppose the condenser could have been taken off for that reason?

 

Nope.
Rad or condenser can be removed without interfering with the other.

 

I have an S4, and that does not look like my radiator. You have a radiator cap on the top of the radiator, and mine does not. My cap is at the coolant neck where the upper hose meets the engine; I can't really tell from your picture, but it appears you do *not* have one there. This probably means your coolant is not topped off, because you cannot get it up to the proper level from a cap on the radiator. See the FSM or Haynes manual for the process to top up the coolant, it is not like other cars. There is supposed to be a bleed screw on the right (left in your photo) side of the plastic neck at the top of the radiator where the hose connects. You need to open that to top it off, and you have to add the coolant from the higher point (by the engine) so that it fills up the hose.

It also appears that you are missing the air induction duct. It attaches to the air filter box, comes across to the left side of center, and then forward over the top of the radiator. This is not a big deal, but without it your system is drawing air from inside the engine compartment instead of from the (cooler) airflow forward of the radiator.

You can pick one up at a junkyard for not too much, or perhaps one of the members here who has recently installed a performance air filter system will have his old one laying around. But it may not fit with that radiator cap right there; that may be why it was removed.

 

^ That looks like an S4 radiator to me. One way to be sure is to look on the bottom of the radiator, if there is a two wire sensor plugged into the bottom then it is an S4.

 

There are two versions of the S4 radiator. Some have the cap on the radiator itself, and some have it on the thermostat cover.

S5 radiators have the cap on a spot near the battery instead (on the radiator). The above pic would be of an S4 radiator.

 

That was actually how I realized that the radiator is S4--the air intake duct I pulled from a junked S5 did not fit.