the evil smoke at start up -- emergencyish

[jefla]

I've a 2000 Boxster w/ 45 k miles that is suddenly billowing white smoke at start up. Previously, I would see this once or twice a year. Friday I drove it 500 miles to visit my bro (so I'm currently 500 miles from home) and now it billows at every start up. It does finally stop emitting visible smoke after a few minutes. First, what's up. Second, or first, can I drive home (500 miles of highway) tomorrow then get it repaired?

Thanks

[jefla]

Here's more info. Car has new oil, and there's no sign of collant in the clean oil on the dip stick. Coolant level is actually too high -- about an inch below the top of the filler. Car runs beautifully.

I've a 2000 Boxster w/ 45 k miles that is suddenly billowing white smoke at start up. Previously, I would see this once or twice a year. Friday I drove it 500 miles to visit my bro (so I'm currently 500 miles from home) and now it billows at every start up. It does finally stop emitting visible smoke after a few minutes. First, what's up. Second, or first, can I drive home (500 miles of highway) tomorrow then get it repaired?

Thanks

[Rodger]

Sounds like you might have a failing oil seperator. I would pull off the short convoluted hose running from the AOS to the intake manifold and look for a large quantity of oil. A small amount is normal (think 'condensed vapor') inside the tube.

In this pic, you can see the AOS on the lower right, with the short convoluted hose running to the intake.

[jefla]

Rodger -- That's a such beter answer than valve stem seals, which is what I'm fearing. I hope you're right, thanks a lot for the photo.

I need to be back home in DC by mid-afternoon --meaning leaving 5-6 AM tomorrow. Can I drive home w/ a bad separater (500 mi), or ... valve seal?

[Chris_in_NH]

Rodger -- That's a such beter answer than valve stem seals, which is what I'm fearing. I hope you're right, thanks a lot for the photo.

I need to be back home in DC by mid-afternoon --meaning leaving 5-6 AM tomorrow. Can I drive home w/ a bad separater (500 mi), or ... valve seal?

you *can* drive home (or *try*, anyway.)

i would check that tube first. if it has a lot of oil in it (more than a misting) it's probably better to fix your car and then drive home. you can DIY in 2 - 3 hours and there are plenty of how-to's with pics. the AOS and J-tube will cost about $120 together. overnight shipment is about $25.

when the AOS goes bad, it starts feeding (lots of) oil into the engine, which is why it smokes. at one point, if left untreated, one or more of the cylinders could fill with (un-compressible) oil, and something has to give (your engine!)

if you do drive home, keep an eye on the smoking. if the smoke is going away after a while, you're probably ok. if the car is not running rough yet and there's no CEL or flashing CEL, chances are the AOS has not gone completely bad yet.

the other thing to keep in mind is that some smoke upon start-up is normal for flat-6 engines. especially if you just moved the car a few feet and then turned it off. is it possible that you just noticed this, but it has been smoking like this all the time you've owned it? when the AOS goes bad, the car will smoke the whole time it is running and you won't be able to see your neighborhood. (yes, it's really that bad.) ;)

Edited June 18, 2007 by Chris_in_NH

[jefla]

I found Rodger's AOS DIY post. This looks DIY-able, but not before I get home. BTW, my cel is on now, not flashing, but unfortunately I also can't read codes. And the smoke screen is gone in about 15-20 seconds. No smoke therafter until I shut it off.

[Chris_in_NH]

if there is an AutoZone near you (or on your drive home), they will let you borrow their code reader for free to read your codes and reset the CEL. then at least you would know the codes.

you said your car isn't running rough and the smoke goes away after 15-20 seconds. that sounds like normal flat-6 smoke to me. i would just keep an eye on it.

Edited June 18, 2007 by Chris_in_NH

[jmj996]

I found Rodger's AOS DIY post. This looks DIY-able, but not before I get home. BTW, my cel is on now, not flashing, but unfortunately I also can't read codes. And the smoke screen is gone in about 15-20 seconds. No smoke therafter until I shut it off.

I had an identical problem with our 1999 986, I also began to see billowing smoke at every startup. If you're as lucky as me, the smoke is just unburned fuel, but as I read the 2000 Boxster system is a little different than the 1999 system. The dealer fixed the problem on my 1999 relatively inexpensively. There is an air injection valve whose purpose (as I understand it) is to lean out the mixture on startup. When it stops functioning, your mixture will be way too rich on startup.

As far as the CEL, it may finally be indicating the failed valve.

Here is some possible useful info from the PCA site on a forum question regarding secondary air injection faults:

QUESTION:

I appreciate your previous assistance and finally found a operation in Bozeman that could read code for me. Here is the data derived:

1. PO410 Secodary Air Injection Problem

2. P1411 Undocumented Code

They also cleared the code which may or may not last. Where to I start? Thanks

ANSWER:

Both of the faults that you have listed are for the Secondary air injection. P0410 is for cylinders 1-3 and P1411 is for cylinders 4-6. To cause a fault in both banks would have to be from a common user. The most common problem with all the Secondary air injection systems is the cut off valve or the check valve up to 1999. The cut off valve is vacuum actuated by a solenoid. When actuated it allows the air to flow to the exhaust ports in the cylinder heads. To keep the exhaust gasses from going back into the air pump and damaging it the check valve blocks it off. This valve is what they call a one way valve. Both of these valves are actually the same as what was used in the 993's. Having said that we can find a direct correlation between both of these cars having the same problems. Generally the 993 will require the check valve while the Boxster will use the cut off valve. From 2000 on the Boxster uses an improved version that combines both of these valves into one unit.

In the Boxster the air pump is located on the passengers side under the engine cover. The hose that comes off of the air pump goes to the cut off valve unit up to 1999 or the combo cut off valve from 2000 on. On the 1999 and before years there is another hose from the cut off valve that goes to the check valve.

Step 1) To test the cut off valve it will have to be removed and checked. Since the fail rate in the Boxster is so high for this part I would suggest you have a new one to reinstall. Once removed you can hook up a vacuum source to the valve and blow into the valve. Blow in the direction of the arrow and you should be able to do this with no resistance. This should block off all the way when the vacuum source is removed. This test can also be done on the car with a Porsche tester and checked. Should this check out OK then go to the next step below and fallow. This will not usually be necessary.

Step 2) Check the air pump next. This is generally done with a Porsche tester, however you can supply voltage and ground to its wiring to make it run. Pin 1 on the air pump is positive and pin 2 is the negative or ground.

Step 3) Check the vacuum to and from the solenoid valve when actuated. This valve is electrically operated and switches the vacuum on and off to the cut off valve. These have gone bad, but are not as common.

This would conclude the testing for a 2000 or newer Boxster. Should all of the above be correct on a 1999 and previous Boxster, replace the check valve.

This is not Porsche's testing order. I have found this testing order to be more direct for the most common failed parts and for ease of testing. I have listed the part numbers below for the valves.

1999 and pre Cut off valve 993 113 245 00

1999 and pre Check valve 993 113 250 03

2000 and newer Cut off Valve 996 113 249 01

Change-over valve (Vacuum Solenoid) 996 605 123 01

Scott Slauson - PCA WebSite - 6/25/2004

[CJ_Boxster]

Good stuff John Jones. Do you know weather the test procedure works for a 99 or older boxster? I used to only pull P0410 but now i get both codes P1411 and would like to try this myself.

[Loren]

A little clarification...

P1411 Secondary Air Injection System, Bank 2 – Below Limit

Potential causes:

- Secondary air injection pump does not function

- Air supply lines restricted

- Electric change-over valve does not function

- Air change-over valve does not function

- Vacuum system leaking

[jefla]

Drove it home. Ran perfectly, and got good mileage. Nerve wracking! Car still billows smoke at start up. Definitely more the longer it has sat, plus it's suddenly getting worse in that it started blowing (not billowing) smoke while driving. This occurred very soon after I noticed that it was idling rough. CEL is (still) on and got codes P1128, P1130 and P1126. (Used Advanced Auto Part's device -- I definitly need to get one of my own.) Net research suggests problem is MAF, because P1128 and P1130 indicate both banks of cylinders are running lean. Correct?

It seems thatI should 1) check for intake leaks, particulalary at air oil separatoer bellows and 2) clean or replace MAF. Is tgis correct?

Thanks

[jmj996]

Good stuff John Jones. Do you know weather the test procedure works for a 99 or older boxster? I used to only pull P0410 but now i get both codes P1411 and would like to try this myself.

No, I just quoted the PCA site on that one. The only personal insight I have on this is the symptoms I experienced with my own 986 and the explanation from the service manager. Keith George was my service manager in Hawaii (and a gearhead in his own right), and the guys in the shop (mainly Aaron) would personally show me what they were doing with the car, and they were all great, I wish I didn't have to leave Hawaii. Someday when we're not moving all the time (wife is in the service) I'll get a lift and computer interface and get more hands-on with these cars like I was with my American sports cars.

I love your Boxster. Its appearance is identical to the '99 Boxster we had, it is a gorgeous package. We never would have sold it if we didn't have the kids, but they're definitely worth it. It actually took us two years to finally part with it if after we picked up the 996, but we ended up selling it to another couple that was looking for their first Porsche, so it was fitting.

Edited June 23, 2007 by John Jones

[jmj996]

Drove it home. Ran perfectly, and got good mileage. Nerve wracking! Car still billows smoke at start up. Definitely more the longer it has sat, plus it's suddenly getting worse in that it started blowing (not billowing) smoke while driving. This occurred very soon after I noticed that it was idling rough. CEL is (still) on and got codes P1128, P1130 and P1126. (Used Advanced Auto Part's device -- I definitly need to get one of my own.) Net research suggests problem is MAF, because P1128 and P1130 indicate both banks of cylinders are running lean. Correct?

It seems thatI should 1) check for intake leaks, particulalary at air oil separatoer bellows and 2) clean or replace MAF. Is tgis correct?

Thanks

P1126 appears to be a response from the DME that is directly related to P1128 & P1130. These two codes are specific to the left & right cylinder banks, and P1126 means that the engine is running lean and the DME cannot compensate to make the engine run richer. Sounds like the exact opposite problem I had (running rich), so I'm probably not much help.

Looks like you are on the right track. The PCA forums for P1126 suggest a MAF problem (and be sure to check that the air filter is not clogged). Please reply with the final solution!

Edited June 23, 2007 by John Jones

[jefla]

[EDITED TO COLLECT ALL SYMPTOMS HERE.]

I've a 2000 Boxster w/ 45 k miles that is suddenly billowing white smoke at start up. Previously, I would see this once or twice a year [but big puffs, not billowing].. Friday I drove it 500 miles to visit my bro (so I'm currently 500 miles from home) and now it billows at every start up. It does finally stop emitting visible smoke after a few minutes. [clip]

.

The board gave me the confidence needed to drive it home, which I did and all was fine. Actually ran sweet. One add'l sympton, after driving 500 mi it started smoking a bit at v/ low rpm and the idle became erratic. Finally, I eventully pulled codes P1126, P1128 and P1130.

GOT IT RESOLVED -- I'm pretty sure it was solely the air oil separater -- although I also changed an obviously cracked oil filler tube (center segment).

Some diagnostic notes follow. 1) Someone suggested the following as an AOS check (sorry I could not relocate post to credit author): Disconnect the "short convoluted" tube running from the AOS to the throttle body (see image in Roger's post, below). Seal the opening at the TB. Start engine and let run a bit, then let it sit a few hours and restart. If there's no smoke at second start up then the AOS is the problem. ... When I ran this test there was clearly less smoke at the post-sitting start up, but it definitely still smoked a bit. Still, I'd say that if there's a big change in smoke volume then the test proves it's the AOS. 2) My billowing smoke was white, like burnt fuel, and had a new-to-me odor to it. Not really sweet, definitley not the odor of petroleum based oils. 3) When I removed the coupling at the TB there was lots of oil in the tube -- not merely vapor residue -- plus a relatively new pool of oil had formed on the block just below the coupling. I'm confused by the pool of oil because it seems that any opening allowing oil to drip would have been a whopper of a vacuum leak. Finally, based on the appearance of the oils caked up around the leaking oil filler tube, that thing had been leaking for a long time.

I paid a shop to do this repair (Autobahn Motorworks, Bethesda MD), primarliy because I don't currently have the ability to read codes. They charged $790 parts and labor to replace AOS and filler tube. Thanks for everyones' help.

[Rodger]

Thanks for the follow-up, glad you got it sorted!

For the DIYers:

I replaced both my AOS and the center oil filler tube segment in about two hours, having never done either before.