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-   -   bad oil separator? (http://986forum.com/forums/boxster-general-discussions/16488-bad-oil-separator.html)

wanna986 04-26-2008 07:29 AM

bad oil separator?- update
 
Before replacing a good part, can anybody confirm that this could be happening as a result of a bad oil separator?

2002 986 S
I have a situation where oil is pooling on top pf the engine on the passenger side. There is definitely oil in the throttle body and oil film around the body of the separator.

Now, if the unit is bad, is it possible for oil to start backing up through the filler tube and escape at the junction, making its way along the underside of the tube and eventually dripping on the engine where I see it? The accumulation appears to be directly below the path of the tube, so this is why I'm asking. The junction of the filler tube is slightly wet.

Finally, I am talking about pooling, not just wet spots typical of seepage.

Anybody hazard a guess?

Lil bastard 04-26-2008 08:04 AM

Well 1st check to see all hoses are intact and not split.

Other than that, it does sound like the AOS.

Not too bad a fix. Good Luck

silverboxter 04-26-2008 03:11 PM

not sure if this is the same problem as yours. my wife's S would drip oil on the exhaust. you could smell it for hours in the garage after it was parked. i took it to autohouse bavaria in san jacinto, ca. turned out that there was a loose/stripped valve cover bolt that was causing the leak. it was a $89 fix.

wanna986 04-26-2008 10:03 PM

Thanks for the replies.
There is no smell associated with this.
I'll be sure to check the condition of the hoses.

kbrandsma 04-26-2008 10:44 PM

When the AOS goes it can cause the Oil filler tubes to expand and contract and eventually fail. This failure will cause oil to pool on top of the engine on the passenger side. Check some of the threads on this site by searching oil filler tubes. If your AOS is replaced you should also replace the J tube which connects the AOS to the throttle body(TB.) You can remove your J filler tube at the TB and see if their is any accumulation of Oil (a sign of a bad AOS.) Good luck!

tboyer 04-27-2008 04:42 AM

Quote:

Originally Posted by wanna986
Before replacing a good part, can anybody confirm that this could be happening as a result of a bad oil separator?

From what I understand, you can start your car, pop the trunk, try and remove the oil cap. If it removes with little or no effort, that's good, if it is difficult to impossible to remove then that's a symptom of AOS failure.

wanna986 04-27-2008 06:51 PM

I will check the J tube for oil and try the oil cap test as well.
Is Sunset still the cheapest source for the oil separator?

kbrandsma 04-27-2008 09:37 PM

Checking the oil cap in the trunk is a good test before the oil filler tubes crack and leak. If they are cracked and leaking there is no vacuum to keep you from unscrewing the oil cap.

John V 04-28-2008 04:07 AM

If oil is pooling on top of your engine your oil fill tube is leaking. It may be cracked or it may just have a leak in the joint between the upper fill tube and the tube that meets the engine. The oil fill tube is a thin black plastic tube which is about 1.5" in diameter. If you run your finger under the underside of it and it comes back with fresh oil, you know that joint is leaking.

I disassembled mine, cleaned the interface with acetone, then sealed it with RTV since it was not cracked. No leak.

wanna986 04-28-2008 06:23 PM

Quote:

Originally Posted by John V
If oil is pooling on top of your engine your oil fill tube is leaking. It may be cracked or it may just have a leak in the joint between the upper fill tube and the tube that meets the engine. The oil fill tube is a thin black plastic tube which is about 1.5" in diameter. If you run your finger under the underside of it and it comes back with fresh oil, you know that joint is leaking.

I disassembled mine, cleaned the interface with acetone, then sealed it with RTV since it was not cracked. No leak.

My pooling is safely a few millimetres deep and is contained by the waffle design of the casting.

So the AOS may be o.k. and it's just a leak at the junction? I guess my question is "What's the oil doing way up there?"

I have to try the oil cap as soon as I can.

Thanks, all.

John V 04-29-2008 04:57 AM

Way up where, in the oil fill pipe? Oil vapor is present in that pipe and if the seal isn't perfect, it will drip down. Pretty simple.

Lil bastard 04-29-2008 07:05 AM

In addition to de-foaming the oil, it's also an emissions device to keep the crankcase vapor from venting to atmosphere. Instead, it is drawn into the intake and burned during combustion.

Zuffen 04-29-2008 11:46 AM

Quote:

Originally Posted by John V
If oil is pooling on top of your engine your oil fill tube is leaking. It may be cracked or it may just have a leak in the joint between the upper fill tube and the tube that meets the engine. The oil fill tube is a thin black plastic tube which is about 1.5" in diameter. If you run your finger under the underside of it and it comes back with fresh oil, you know that joint is leaking.

I disassembled mine, cleaned the interface with acetone, then sealed it with RTV since it was not cracked. No leak.


Hey John V, I think this is exactly what is happening to my 2000 Box. I do not think my AOS is bad (new version and pretty clean all around it) No smoke from the exhaust. I did get the pooling of oil on the passanger side and underneath the join of the fill tube there is oil.

Question: How was the removal and cleaning process? Any guidance on how to do it will help. What is RTV?

Thanks in advance.

-Zuffen

Lil bastard 04-29-2008 02:54 PM

It is a silicone sealant. RTV stands for Room Temperature Vulcanizing. Most general purpose silicone sealants are RTV type. It generally uses an acedic acid based solvent and is characterized by it's vinegary smell.

This form of sealant starts to cure as soon as it is exposed to air/moisture.

There are several types of silicone sealant.

Anaerobic silicone is usually 2 parts which must be mixed together and sets quickly. It does not require exposure to air to cure. It is often used in sealing engine halves, valvecovers, etc. where the silicone is pressed between 2 surfaces and not exposed to air.

UV or Radiation silicone sealant will only cure under exposure to ultraviolet light.

There is also Thermo or Thermoset silicone sealant requires exposure to heat in order to cure.

wanna986 04-29-2008 05:12 PM

results of oil cap test
 
There is definitely vacuum present when I remove the cap.

Once the cap is removed, the engine starts to get rough, stumble and "chug". I put the cap back on and things smooth out. What's this say?

wanna986 05-03-2008 06:11 AM

***bump***
 
Are my findings consistent with the need to replace the oil separator?

Burg Boxster 05-03-2008 06:45 AM

Not necessarily...... it depends on the strength of the vacuum. If you could easily pull off the cap, then AOS might be ok. If there was a severe vacuum which required a lot of effort on your part to remove cap then yes AOS might be bad.

Diagnosing a failing AOS is difficult (as you can tell) unless of course until it has completely failed - which you don't want to have happen. Some visual cues / things to look ar for help determining if it might be failing are:

Smoke - more than just a puff on start up (does it occur on hard accelleration, at idle after engine has been running a while, etc.)

Bellows - drips of oil below/on it, tears, degrading rubber, splits

J-tube - disconnect it at the TB. Look for puddling (more than what a misting would leave) in the tube and or in the TB.

Remember, this part since being intro'd on the '97 Boxster has been revised 4 times (5 iterations total....... so far). On avg, every 2.2 yrs PAG thinks they have a correct solution for it's purpose. In my opinion if you don't have at least version .03, it's really a matter of when not if it will fail. From what I have experienced/heard/seen/etc., the .02 versions and prior usually last < 50K miles.

Changing it out is cheap insurance for what could be catastrophic results when it fails. Parts are ~ $120 US and install takes under 2hrs DIY.

wanna986 05-03-2008 06:57 AM

Thanks, Burg.
It wasn't difficult to remove the cap, but I didn't expect that the engine would react so violently to the cap being off. I hadn't read anything about that in my searches.
I'll remove the j tube.
Thanks for the suggestions.

Gary in BR 05-03-2008 07:18 AM

I found a AOS for under $100.


http://cgi.ebay.com/ebaymotors/Porsche-Boxster-thru-02-Oil-Seperator_W0QQcmdZViewItemQQ_trksidZp1638Q2em118Q2 el1247QQcategoryZ46098QQihZ009QQitemZ190111551349Q QrdZ1QQsspagenameZWD1V

Burg Boxster 05-03-2008 12:34 PM

Good find Gary - just know they list it as version .03
Porsche has had version .04 out for > 1 year now (maybe 2?). I don't know what changes were made from .03 to .04 but obviously they tweaked it some.

The price I quoted above ~ $120 is what I paid from Sunset Porsche in OR for:
- new AOS
- new J-tube (not necessarily required - depending on which previous version you have or if yours is clean)
- grease (for the rings on the bottom)

Price including shipping to PA too.


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