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-   -   AOS - Question (http://986forum.com/forums/boxster-general-discussions/63007-aos-question.html)

Muskoka Minute 09-03-2016 10:08 AM

AOS - Question
 
My son has a bad AOS on his 2003 base.
We have ordered the new part but it will not be here until Wed.

Here is the question.

1. Is he safe to run the car until we can change the part?
2. If not can he run the car if we disconnect the hose (and plug the port) going to the intake and leave the AOS hose open?

We don't want to damage the car but its his only form of transportation.

Please let us know.

Bart

rexcramer 09-03-2016 10:10 AM

How badly is it blowing smoke?

911monty 09-03-2016 10:12 AM

Quote:

Originally Posted by Muskoka Minute (Post 508816)
My son has a bad AOS on his 2003 base.
We have ordered the new part but it will not be here until Wed.

Here is the question.

1. Is he safe to run the car until we can change the part?
2. If not can he run the car if we disconnect the hose (and plug the port) going to the intake and leave the AOS hose open?

We don't want to damage the car but its his only form of transportation.

Please let us know.

Bart

I would not run it. Besides evacuating vapors from the crankcase for emission purposes, the AOS also places the crankcase under a vacuum. This is important for the low tension piston rings to seal. If i am AFU I see JFP in PA is on and will correct me. :)

Muskoka Minute 09-03-2016 10:12 AM

When you first start it there's a fair bit smoke. (smoke cloud)
After you run it for a bit it clears up.
Shut it down for 10min and it does it all over again.

JFP in PA 09-03-2016 10:42 AM

Quote:

Originally Posted by Muskoka Minute (Post 508819)
When you first start it there's a fair bit smoke. (smoke cloud)
After you run it for a bit it clears up.
Shut it down for 10min and it does it all over again.

Don't run it, it simply is not worth the risk.

dghii 09-03-2016 11:41 AM

Agree, Don't drive the car.!
Look at it this way, the part failed in a convenient location and has done no other damage.
Renting a junker or borrowing a car will still be cheaper than this repair would be if you had to get towed or pay a pro (no offense JFP!!).

Luckily, it is a pretty easy replacement on 2003's....all from the top. Get or borrow the hose clamp tool....you know, the one that has the extension to reach into places you can't get pliers on.

When you first look down at the clamps and bolts that have to be removed it will look pretty tough. Just be patient and you'll find you can get to everything without having to do anything special. A magnetic pick up tool helps to remove the AOS bolts you've loosened.

Put some protection over the trunk and fender as their's a fair bit of leaning over to get the AOS.

NewArt 09-03-2016 12:25 PM

One of those little inspection mirrors will help a lot when replacing that lower bolt!

heliguy 09-04-2016 11:23 AM

Don't run it! My AOS cost me my engine at 105K miles.

thstone 09-04-2016 01:24 PM

As others have said, don't run it.

Would you walk into a casino today and lay down a $5,000 bet? If not, then don't run it. If so, then it looks like the weather in Bracebridge is in the high 70's so it should be a perfect afternoon for a nice drive. :)

Muskoka Minute 09-04-2016 02:17 PM

We have taken your advice and parked it until the parts come in.

Bloody dealers say this that and the other thing...

I gave him my spare car until I can go over it in the nest couple of weeks and bring it up to where we have a bench mark.

Once again we want to thank you guys for having our back!!!

Cheers!

Bart

Muskoka Minute 09-10-2016 02:07 PM

well this is where were at...

I just changed the AOS and here is what we did etc.

1, Started the eng and we got less smoke than normal. (check eng light was still on) After 5-10 min the smoke was all gone.
2. let it ideal for approx. 15min
3. took it for a test drive. After approx. 3 mile. It was running rough, check eng light was flashing.
4. shut it off
5. restarted - running rough. shut it off
6. re started, started for home. It started to run better and the check eng went to solid and not flashing. Shut it off
7. Got home and re started. Runs like **************** and is making noises.

Here is the video.

https://vimeo.com/182244036

You will have to cut and past as I don't know how to make it an active link.

Please Help!!!

It ran perfect after the first fire up with the new AOS.
I have no idea why this is happening.

911monty 09-10-2016 04:20 PM

I'm assuming you do not have a Durametric, so what I'd do is pull your spark plugs, you may have fouled a few when ingesting the remaining oil while idling. Hopefully the banging and clanging is the DMF being thrashed about. Good Luck

Muskoka Minute 09-10-2016 04:23 PM

Why is dmf.

911monty 09-10-2016 04:25 PM

Quote:

Originally Posted by Muskoka Minute (Post 509700)
Why is dmf.

DMF is dual mass flywheel. It is designed to dampen harmonic vibrations from the crank. Basically a sprung weight.

husker boxster 09-10-2016 10:47 PM

Your MAF could also be oily and needs cleaning. These are side effects of running with a failed or failing AOS (fouled plugs, dirty MAF) - oil gets into areas it shouldn't and causes issues after the AOS is changed.

Smallblock454 09-11-2016 02:00 AM

Hello Muskoka Minute,

so the car did run well for a short time (3 miles) and than these noises and the engine light came up. That noise doesn't sound good.

That noise is not a DMF. You will hear a bad DMF only if you engage the clutch at the point between slip and engagement - mostly in first or reverse gear at lower revs.

What to do:

1. step)
  • If you have a Durametric or any other diagnostic tool note all error codes and check their meaning.
  • Unconnect the starter battery.
  • Pull all spark plugs and clean them. There might me oil and crust on them. Check the electrode distance.
  • Turn over the engine while the sparks are out. Aprox. 2 times for 5 seconds. Check if oil is coming out of the spark plug hole and how much.
  • Put in all sparks.
  • Remove the MAF and clean it.
  • Remove as much of the air intake system after AOS and MAF and clean it. There will be lots of oil in it.
  • Put everything together, connect the starter battery.
  • If you have a Durametric or any other diagnostic tool reset all errors.
  • Start the engine.
  • If it runs without unususal noises or anything else – OK.
  • Do a test drive.
  • If you have a Durametric or any other diagnostic tool check error codes.
  • If you don't have codes or anything else – repair done.

If you have the same noise and the engine is not running well like in the video, we have a bigger problem. In that case do not drive the car or start the engine.

2. step)
  • Do a pressure test for each cylinder.
  • If all cylinders are in the same compression range, use an endoscope to take a look at all cylinder walls.
  • Drain the engine oil. Check what you find in the oil filter.
  • Unmount the engine oil pan. Check what you find in the oil pan.

If can't find something unusual, start the engine and check if you can identify where that hard knocking noise is coming from / if you can locate it.

Hint: Don't do a compression test without engine oil in the engine. ;)

Hope you don't need to do the 2. step.

Regards, Markus

911monty 09-11-2016 09:15 AM

Thanks Markus I was trying to be optimistic that's why I said hopefully! I think there needs to be a sticky somewhere on the steps to take after an AOS failure, I modified your steps as a first attempt. Hope you don't mind


What to do: Do Not attempt to start the engine until all steps below have been completed as serious damage to the engine can result!

1. steps to take after AOS failure.
  • If you have a Durametric or any other diagnostic tool note all error codes and check their meaning.
  • Pull all spark plugs and clean them. There might me oil and crust on them. Check the electrode distance.
  • Remove Fuel pump relay.
  • Turn over the engine while the spark plugs are out. Aprox. 2 times for 5 seconds. Check if oil is coming out of the spark plug hole and how much.
  • Put in all sparks plugs.
  • Remove the MAF and clean it.
  • Remove as much of the air intake system after AOS and MAF and clean it. There will be lots of oil in it.
  • Install fuel pump relay. Start the engine.
  • If it runs without unususal noises or anything else – OK.
  • Do a test drive.
  • If you have a Durametric or any other diagnostic tool check error codes.
  • If you don't have codes or anything else – repair done.

SeanBuller 09-11-2016 09:31 AM

Hi Guys,

We are currently trying out the procedure listed above. We swapped the upstream O2 sensors between bank 1 and bank 2 (bank 1 is misfiring). We cleared the codes for the vehicle and started it up. Still idling poorly and making the noise in the video above.

The CEL did not come on, but we are getting code P0012 which says "intake camshaft position timing -- over-retarded (bank 1)". Along with P0300, P0301, P0302, P0303. All relating to misfires of cylider 1-3 (Bank 1).

We have cleaned the MAF and now replacing all 6 spark plugs.

Is anyone familiar with these symptoms? Especially P0012.

Thanks!

911monty 09-11-2016 09:43 AM

Hey Sean; Before you reinstall those spark plugs, I'd recommend doing a compression test. If you do not have one there are loaners available from AutoZone, O'reilly's etc. Unfortunately it may be time to implement Markus' phase 2 plan. Hoping for the best!

Gelbster 09-11-2016 10:01 AM

Perhaps it would be useful diagnostic evidence to use a stethoscope to locate the exact source of the metallic clattering noise ?
The splash shield underneath the engine is already removed(?) so access is easy.


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