FirstPorsche

The Car: 1987 944S
1) I cleaned my K&N filter last night and noticed that there was a plastic elbow connector heading out of the back of the airbox. It was SUPPOSED to be connected to a rubber hose that led down to the front of the engine (about as technical as I can get. Sorry.). I re-connected it and have noticed no difference in how the car runs. I have looked in my books but see no reference to this hose.
2) (I apologize in advance for the poor description.) Also, right above the oil filter there is a gold colored cylindrical device that has a rubber elbow connector that is SUPPOSED to be connected to a small black plastic straw-like hose that leads down the block. I re-connected this too and again noticed no difference in how the car runs.

Any ideas?

Thanks much.

F18Rep

Your description of #1 is, I believe of the venting of the timing/balance belt covers. I'm guessing a bit but I think that is meant to help keep the belt area clean - not really critical, just a good idea.
<img src="http://www.arnnworx.com/SilverNBlack2.jpg" alt=" - " />

On your #2 There is the oil pressure sending unit near (but below) the oil filter? I guess I don't know what you're referring to on that one.
<img src="http://www.arnnworx.com/engineLeft1.jpg" alt=" - " />

IceShark

The first hose connects to the belt cover on the front of the motor. Porsche actually came out with an update and told everyone to cap that hose off. Remove it.

Someone more knowledgable can correct me here, but I believe the original thinking was pollution control. It didn't really do much to cut down on pollution and could cause problems.

I'm not sure what you are talking about on item #2.

W88951

The hose was there to cool off the belts and rollers by allowing cool air into the housing. In practice it caused injestion of dust, limiting the life of the belts and rollers. Therfore, they plugged it off and removed the hose. That is if I recall correctly (IIRC).

IceShark

Andrew, how can that be correct? Is there an inflow vent somewhere? Otherwise that hose is under vacuum and isn't going to allow cooling air in.

ZV

For #2, I'm not sure but there seem like about a billion small vacuum lines on these engines and it's just a good idea to have them all connected.

I like having the belt area vent hose connected myself, it's an easy way to see if the belts are doing bad things since I check my air filter about every 5,000 miles. If there are bits of rubber in the air filter, I know that there is something very wrong with the belts even if it hasn't been 30,000 miles.

Aaron

FirstPorsche

Thanks a lot for your help.

I am bringing my car to Auto Associates in Canton (a GREAT service place) next week and will ask them whether or not I should cap that hose.

I will also ask them about my #2 question. I have replaced the oil pressure sending unit so I am familiar with that. But this gold thingie is above the oil filter. Hmmm... I will let you guys know what my mechanic says.

Thanks!

MHT

I'm not sure about the gold "thingie" but the heater control valve is just above the oil filter on an S, may be that is what you are referring to. If the vac. hose to that is disconnected the control unit is unable to shut off the coolant flow to the heater core.

RJP 951

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by ZV:
<strong>I like having the belt area vent hose connected myself, it's an easy way to see if the belts are doing bad things since I check my air filter about every 5,000 miles. If there are bits of rubber in the air filter, I know that there is something very wrong with the belts even if it hasn't been 30,000 miles.

Aaron</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">If the vent on the NA is routed in the same way as a Turbo, then it's on the wrong side of the air filter to rely on that to prevent ingestion!

I'm pretty sure that's the reason for the tech bulletin... little bits of belts and dust going straight into the engine was determined to be worse than whatever benefit the vent had in the first place.

My local dealer had the necessary caps for just a few bucks.

Ron

FirstPorsche

THE ANSWER:

After discussing the airbox hose with my mechanic yesterday he stated that it SHOULD be connected. He said that the hose is more of a benefit than a risk.

I already know there are differeing opinions but I thought I would pass this along.

Thanks!

Luis de Prat

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by MHT:
<strong>I'm not sure about the gold "thingie" but the heater control valve is just above the oil filter on an S, may be that is what you are referring to. If the vac. hose to that is disconnected the control unit is unable to shut off the coolant flow to the heater core.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I think MHT has the answer. Although the OE heater control valve (front-mounted on the S cars) is a black plastic unit with a white plastic lever, this car may have the updated "Audi 5000" HCV, which is all brass and lasts considerably longer.

When you reconnected it you probably couldn't notice any difference because you're not using the heater these days <img border="0" title="" alt="[Wink]" src="wink.gif" />