dan_189

Hey all,

Was under my car today checking the engine mount sag (which looked in good condition) when I noticed a corrugated hose that was damp/leaking with oil. No drips just looks like it's weeping, is this the crankcase breather line for the right side of the engine? First pic is under the engine on the left side. Car is a 2004 C2 83kms.

Is it easy to replace? It looks like it weavs its way through the engine so it doesn't look easy. As well as the fact that it might connect into the AOS which has limited access.

My documentation says the AOS was replaced before I purchased the car under 10,000kms ago.

Any ideas?





​​Thanks!

Ahsai

There's an o-ring on each end of that AOS vent hose. The left side is plugged into the AOS. Could be the o-ring but hard to say without looking at it. Regardless, it would be good to replace the AOS and address the left end o-ring. The right end is hard to access so unless it's leaking, better leave it alone.

If the AOS hose needs replacement, that's a lot of labor.

dan_189

Thanks Ashai, AOS was replaced in 2015 from memory, I'll have to check my records.

Any chance they could just be a crack in that corrugated hose as it seems to be damp all the way along it from near the coolant tank all the way to behind the engine?

Could the O ring cause the oil to spread all the way along the hose?

Ahsai

Hard to say as the draft in the engine compartment can help spread the leak. I would start at the AOS end and see if it's leaking or unseat there first (with a small inspection mirror).

Ahsai

Purple arrow

http://cdn4.pelicanparts.com/techarticles/Boxster_Tech/09-ENGINE-Air_Oil_Separator/images_small/Pic3.jpg

dan_189

Thanks Ashai, just to confirm is the hose number 4 in this image:



It appears that the line only looks corrugated in sections whereas mine looks totally corrugated.

Upon second inspection it appears there is a line of oil from under the hose.

Could it be that from contact with the coolant sensor it has cause a split?

What should that hose be secured to as it currently in contact with the sensor.

dan_189

Here is a pic of what I'm talking about above in terms of the sensor being im contact with the hose.

dan_189

Found some images that show where the hose goes.




From AOS to other side of the engine, looks difficult to replace im wondering how much access there is to replace the hose on the AOS end.

rockhouse66

I had the same issue. I did replace the o-ring on the hose where it bolts to the right rear of the engine (viewed from behind). I guess I didn't know it was hard to do because I did it with some patience and not too much drama. It did not fix my issue though.

Then during replacement of the coolant tank, I broke the darn thing. It was very brittle so I am guessing it had a hairline crack or two in it somewhere causing the oil film. If you have the engine stripped down to replace the coolant tank, including dropping it down as far as possible in the car, replacing that hose is possible. It took me 2 or 3 tries to get the routing where I thought it should be. I was also able (just barely) to snap it back on the AOS by stretching my arm all the way back and down on the left side of the engine.

Ahsai

Yes #4 is the hose and it should not rub against anything. Sounds like indeed the hose will need to be replaced.

Most likely the alternator and the T plenum will have to come off for more space.

rockhouse66

I did remove the T plenum but not the alternator.

dan_189

Thanks rockhouse and Ashai, the dealership had already replaced the coolant tank when it was in last year. In saying that I think there might be enough space for me to tackle this.

How does the hose clip into the AOS? Planning on removing the airbox and throttle body if I have to my hands aren't huge so hoping I can get away with it or at least try!

​​​​​​Could I be missing some clips that hold that hose away from the coolant sensor?

dan_189

Okay so got under and had a look, I definitely think it's the hose because there was a lot of oil all over the hose but not much near the AOS end.

I was able to get my hand up there but is from underneath the recommended way to detach the hose and connect the new one? I felt around but didn't feel a connector having looked at the images it appears the connector is even further in.

rockhouse66

The hose connects at the RR of the engine with a plastic flange retained by two bolts. You can just see this by removing the air box and peering down from the top with a flashlight. This is where the o-ring is that was mentioned as a replacement item. The other end of the hose connects to the AOS with a squeeze type connector. You squeeze it to remove it and push it on until it clicks to replace it. You can pretty much see what I am talking about by referring to the parts diagram above.

None of the work to replace this hose is done underneath the engine. Even if you have the transmission out and the engine dropped down, and you attack the AOS end of the hose from underneath, you will be accessing the hose by reaching up and over the AOS to get to the hose connector.

dan_189

Thanks rockhouse, I can see the RR end that is bolted down so all good there.

As for the AOS end, did you reach in via the back facing the engine to disconnect and re connect the hose?

In the diagram that has an O ring as well. Was it hard to replace that or did it sit in the hose?