Much smoke on start up and run - AOS or worst?

[Charlestonboxster]

98 2.5, 86k miles

Started with the odd puff on starting.

Has been blue smoking more and more in the last few weeks.

Definitely a lot on cold start. Even smokes a good bit on warm start, after half an hour or hour off.

Sometimes it's even noticeable in the rear mirror while driving after a few minutes of warm up.

It's getting worse...a few nights ago, while driving back from work, after at least 6-8 minutes running time, I was heading over a very long uphill bridge and accelerating to about 70, and noticed a prominent, medium heavy smoking behind me even at that speed...

Not a very good feeling.

I dropped off the throttle and drifted in neutral back down bridge, smoke stopped right away, then resumed very delicate driving, and, no noticeable smoke.

Any similar experience or thoughts appreciated, the UPHILL aspect of increased smoke was an interesting symptom, and the volume of it was worrying.

Stopped 10 Minutes at grocery store, then the usual heavy blue puffs at startup.

I'm hoping it's just the AOS. I opened her up per Mike Focke page

http://mike.focke.googlepages.com/airoilseparatorreplacement

looking for heavy oil deposit rather then light mist.

There didn't seem to be an excessive amount of oil in the J tube or in the tube connectors on both sides, stuck my finger in all, there was some, but definitely more of a mist then soaking or dripping, at least to my untrained eye.

There were I'd say 4-5 drops worth, a few millimeters deep, in the J tube on the throttle body end, and about 3-4 drops in the tube fitting part of the AOS piece.

Not sure what to do next.

I will definitely order a new AOS to replace the older version.

1- In anyone's experience, do these symptoms sound pretty much like it's definitely the AOS, and I should replace that first,

or is a shop visit really required?

2- Is it safe to drive in the meantime if I drive delicately? Could there seriously be a strong risk of damage, or am I ok if I drive delicately and replace the AOS within 5-6 days?

3- Is connecting the J tube even necessary, and could I run the engine without it, pending replacement?

Thanks to all, I'm awaiting further experience and driving the wife's car in the meantime, ugh...

Tony

PS:

Here is an opinion from PPBB, didn't get any further info or experience, seems to make sense, although I prefer not to have to do without my daily driver for a while if at all possible....

When my '02 AOS was failing though throttle body butterfly valve had a drop or two of oil hanging from its lower edge (which can and did affect idle) and some oil pooled at where AOS tube connected to throttle body (just downstream of the butterfly valve).

Smoking uphill could be due to increased cylinder pressure adding to blowby and putting more pressure into crankcase which would see more vapor being removed and any AOS failure thus directing more oil laden vapor back to intake. Hence the increase in smoke.

My advice is if AOS is suspected is to eliminate this possibility soonest, with as little running of the engine as possible. This risk of serious engine damage, even destruction, is too great to risk, imho.

Whether you want to just go ahead and replace AOS on your own is up to you. Older car, don't know (remember from other posts) how many miles on car, type of driving car has received, care, etc., so an AOS could be the problem.

If you have reasonable auto-mech. skills and don't mind the effort/cost if a new AOS doesn't prove to be the final or only solution, a new AOS could be in your future.

Or, getting car to a shop qualified to make diagnosis and effect a suitable repair is your alternative.

But, with little and best no running of the engine until AOS is replaced or eliminated as source of symptoms.

Sincerely,

MarcW.

[Charlestonboxster]

Drops at hose/tube edge

A few drops at hose/tube edge

Finger swipe in one side of hose, only mist

Definitely the old version, needs replacement

Go Habs Go...

Edited April 20, 2008 by Charlestonboxster

[rsfeller]

How do you tell the old design from the update visually or by code stamp?

[Cassiebox]

How do you tell the old design from the update visually or by code stamp?

The part # on it will tell.

Original OEM on '97 had a .00 ending (not sure when 1st revision was released but it may have been for early '99s ???). They are currently (as of last summer when I R&R'd mine) on part # .04 part (so 4th revisions to original design). Easiest visual difference b/w the .00 and .01 (along w/ all subsequent revisions) is the orientation of the "centrifuge". On the .00 it was horizontal as shown in this pic (looking down into engine compartment from bird's eye view):

In later versions, it is vertical (as shown here comparing the .01 to .04 parts)

Hope this helps. :)

[rsfeller]

great info. I figured there was a visual cue as I didn't see the part number from your first photo. I'm going to do some poking under the hook this weekend and see where I'm at on my 1997 which as far as I know is original and trouble free. I'm still waiting for an AOS, MAF and RMS failure!

[Cassiebox]

great info. I figured there was a visual cue as I didn't see the part number from your first photo. I'm going to do some poking under the hook this weekend and see where I'm at on my 1997 which as far as I know is original and trouble free. I'm still waiting for an AOS, MAF and RMS failure!

Great to hear you're trouble free :)

However, older versions of the AOS have proven to not be a question of if, but rather when. So definitely check yours out. If you have .00, .01 or even .02, I'd replace as a preventative; and with 70K on your clock sooner rather than later. From what I've read/heard/seen - 50K seems to be the "average" life span (of the older versions .01 - less for .00).

Yes most people catch a bad AOS and replace it w/o any problems - especially when just the bellows leak. Others have had catastrophic engine failure casued by a bad AOS. When the AOS fails internally, it creates a vacuum which sucks oil mist (when you're lucky) into the cylinder as opposed to dropping it back into the crankcase. When the vacuum is strong enough it will fill the entire cylinder w/ oil. Since oil does not compress like gasoline... you guessed it - lot's of things get bent/crushed/ruined :eek:

The DIY is easy - takes under 2 hours if you're the slightest bit mechanically. Parts run (as of last summer) $100-110 from Sunset or Suncoast. Dealer repair has been recorded anywhere from $500-800+. Your car and your call but again I'd recommend r&r as preventative (like the polyrib belt) unless your looking for an excuse to do a transplant B)

[Charlestonboxster]

Wow. Ok, ordered AOS from Sunset, did the replacement per Mike Focke's webpage,

http://mike.focke.googlepages.com/airoilseparatorreplacement

Took about 3 hours all said and done, mistakes and learning curve included, took the "cut the bellow off" shortcut,

replaced spring clamps with screw clamps.

Broke the plastic hose retainer part on the hose that hooks into the AOS

near the bellows (not the top), this is a hose that dissapears into the engine somewhere, not sure what it does and didn't have a replacement. So I jury rigged 3 tie wraps to hold the hose tight into the AOS piece, and make sure the hose would not slip out, seems pretty solid.

All put back together, fired up, same blue smoke which I expected, a fair bit in start up then less at idle, but continual.

Idled for 5 minutes, light smoke continued, puffs more with throttle bursts, turned off after 5 min.

Will start up again, idle, see what happens, and report back.

Edited April 27, 2008 by Charlestonboxster

[Charlestonboxster]

FIXED!!!!!

Second start up went fine, surprisingly, no blue smoke at all, not one bit.

A bit of black exhaust, very light, tehn close to clear within a minute.

No blue smoke with throttle pushes.

Looks like the problem is fixed, AOS it sure was, probably the original, with 86K on it, the bellows

almost fell apart in my hands, glad this problem didn't cause any major damage.

Many Thanks to poster above who mentioned the word catastrophic, it encouraged and convinced me to keep my baby garaged until I fixed her, right decision.

Hope this thread helps someone sometime!

Tony