AOS R&R without Turbo removal???
05-20-2019, 01:46 AM
#31
05-22-2019, 11:55 PM
#33
Burning Brakes
Thread Starter
Scheisse! If you look real hard you can see the hairline cracks starting from the holes at about 1 o'clock and 5 o'clock to the I.D, of the pipe. Never ending project!!!
Thanks
Mike G.
Thanks
Mike G.
06-08-2019, 11:33 PM
#35
Burning Brakes
Thread Starter
Don't do what I did!! remember that you need to tighten the bolts to the down pipe while the you have the turbo/downpipe assy on the bench!!! Unless someone can tell me how to get to the bolt that has an interference with the balance shaft cover bolt. If not tomorrow I'm going to do round 2 all over again!!
Scheisse!!
Scheisse!!
06-09-2019, 04:59 PM
#36
Burning Brakes
Thread Starter
Well I figured out actually how to get to that damn bolt that was so hidden next to the balance shaft cover. Take yourself a nice wrench grind it down very thin and bingo you’re there.
09-20-2019, 06:10 PM
#39
Advanced
This is a newbie question so I appreciate your patience.
What are the symptoms of a failing AOS? If high oil consumption is one, what would you expect the rate to be: 1 quart per 1000, 500, 250, 100 miles or something else. When the AOS failed in my boxster. It sucked down a quart in about 300 yards with lots of smoke out exhaust pipe.
In my 87 turbo I seem to have higher oil consumption than expected. My guess its rings, valve guide seals, AOS or trubo. Perhaps all 3. With 65K on the engine, rings and seals seem unlikely. Trubo somewhat likely, but I don't see puffs or smoke out the tailpipe when I jump on the turbo. It would seem the AOS is most likely, but again no smoke.
Thanks
What are the symptoms of a failing AOS? If high oil consumption is one, what would you expect the rate to be: 1 quart per 1000, 500, 250, 100 miles or something else. When the AOS failed in my boxster. It sucked down a quart in about 300 yards with lots of smoke out exhaust pipe.
In my 87 turbo I seem to have higher oil consumption than expected. My guess its rings, valve guide seals, AOS or trubo. Perhaps all 3. With 65K on the engine, rings and seals seem unlikely. Trubo somewhat likely, but I don't see puffs or smoke out the tailpipe when I jump on the turbo. It would seem the AOS is most likely, but again no smoke.
Thanks
09-20-2019, 09:48 PM
#40
Pro
09-21-2019, 06:17 PM
#41
Drifting
First try heavier oil. I've been using 10w60 ten years daily driving.
When I first got the car, it had 69k miles and burned about 1L per 1500 to 3000 miles. If boosting a lot, it doubled that.
I switched to the heavy oil and consumption dropped dramatically: almost zero off boost and about 1L between oil changes.
Today it's almost zero regardless of boosting but I have had the valve seals changed during other work.
Side note: I put 10w40 last winter as a test and consumption returned, albiet at a low rate
When I first got the car, it had 69k miles and burned about 1L per 1500 to 3000 miles. If boosting a lot, it doubled that.
I switched to the heavy oil and consumption dropped dramatically: almost zero off boost and about 1L between oil changes.
Today it's almost zero regardless of boosting but I have had the valve seals changed during other work.
Side note: I put 10w40 last winter as a test and consumption returned, albiet at a low rate
09-22-2019, 12:30 AM
#42
Rennlist Member
09-22-2019, 09:19 PM
#43
Three Wheelin'
This is a newbie question so I appreciate your patience.
What are the symptoms of a failing AOS? If high oil consumption is one, what would you expect the rate to be: 1 quart per 1000, 500, 250, 100 miles or something else. When the AOS failed in my boxster. It sucked down a quart in about 300 yards with lots of smoke out exhaust pipe.
In my 87 turbo I seem to have higher oil consumption than expected. My guess its rings, valve guide seals, AOS or trubo. Perhaps all 3. With 65K on the engine, rings and seals seem unlikely. Trubo somewhat likely, but I don't see puffs or smoke out the tailpipe when I jump on the turbo. It would seem the AOS is most likely, but again no smoke.
Thanks
What are the symptoms of a failing AOS? If high oil consumption is one, what would you expect the rate to be: 1 quart per 1000, 500, 250, 100 miles or something else. When the AOS failed in my boxster. It sucked down a quart in about 300 yards with lots of smoke out exhaust pipe.
In my 87 turbo I seem to have higher oil consumption than expected. My guess its rings, valve guide seals, AOS or trubo. Perhaps all 3. With 65K on the engine, rings and seals seem unlikely. Trubo somewhat likely, but I don't see puffs or smoke out the tailpipe when I jump on the turbo. It would seem the AOS is most likely, but again no smoke.
Thanks
The "AOS" of the 944 is just that, an air/oil separator consisting of a cyclonic chamber to help separate oil droplets from the crankcase vapors. There is no built-in valve to fail (crankcase pressure/vacuum is regulated by fixed orifices and hoses); the only "failure" of the 944 AOS is of the O-rings that go between it and the engine block, which causes a vacuum leak and lean running. The problem with this is that AOS removal in a 951 requires a lot of labor, hence the title of this thread.
As a recap: the breather part that fails and causes excessive oil consumption in certain German cars is the crankcase pressure regulating valve, but since this is attached to the "AOS" assembly in many of these cars, it is referred to as such.