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Pardon the stupid (didn't do a search) newbie question but: "How do you know if you need a new AOS?"
Just bought my 2000 C4 Cab 5 months ago and didn't notice any AOS work done in the available service records; engine runs fine and no apparent oil leaks.
If your crankcase vacuum is higher than 5-7 inches of water (inh20), your factory AOS has a problem. Use a manometer to test this, there are several threads on testing with a manometer.
The factory AOS is known to have a failure of the rubber diaphram, this will cause high oil consumption, smoking, and in severe cases, engine hydrolock. Jake Raby just had two cases of bent rods due to hydrolock from failed AOS's, one of which was only 6 months old.
The UAOS moves the diaphragm to an easy access location, and also has an Accumulator with infra-red sensor to prevent engine hydrolock..
Hmmm, $400 for the UAOS or $25k for Jake to rebuild. And both options are tremendous upgrades from stock
(Picture courtesy of Jake Raby) This one just experienced the wrath of the Porsche Gods due to a failed Factory AOS, same thing almost happened to mine last year at Little Talledega Gran Prix race track, luckily I caught it just in time to avoid this, and it was one of the main reason I put the time in on the UAOS developement..
If your crankcase vacuum is higher than 5-7 inches of water (inh20), your factory AOS has a problem. Use a manometer to test this, there are several threads on testing with a manometer.
The factory AOS is known to have a failure of the rubber diaphram, this will cause high oil consumption, smoking, and in severe cases, engine hydrolock. Jake Raby just had two cases of bent rods due to hydrolock from failed AOS's, one of which was only 6 months old.
The UAOS moves the diaphragm to an easy access location, and also has an Accumulator with infra-red sensor to prevent engine hydrolock..
Thanks for the response.
Don't think I have the problem "yet" but will keep an eye on it.
Don't think I have the problem "yet" but will keep an eye on it.
Good luck ! That's why I designed the UAOS with Accumulator and infrared sensor, the sensor keeps an eye out for oil accumulation that leads to hydolock. It can happen slowly or quick, and sneak up on you. It almost got me and none keeps a better eye on the engine like I do.
Mine arrived today. Hopefully its' more durable than the box it came in
lol, mine also came today and the box seemed plenty durable. Your box looks like it belongs to someone who doesn't give their UPS guy a bottle of booze for Christmas.
lol, mine also came today and the box seemed plenty durable. Your box looks like it belongs to someone who doesn't give their UPS guy a bottle of booze for Christmas.
How did you know?
Maybe I should have also tipped the shipper lol.
Pardon the stupid (didn't do a search) newbie question but: "How do you know if you need a new AOS?"
Just bought my 2000 C4 Cab 5 months ago and didn't notice any AOS work done in the available service records; engine runs fine and no apparent oil leaks.
It'll run fine until it doesn't! Get yours tested ASAP!
I've had one start to fail 6 months after installing a new aftermarket unit...
My AOS was tested good the oil change before it failed, 3500 miles later it hydro locked #1...
Far as I'm concerned its either the UAOS or I might add a active monitor to the damn thing when the motor goes back in.
03-16-2020, 05:53 PM
