caunyd

Hi guys. As I was driving, all of a sudden A LOT of white smoke started coming out from my car. The smoke had a burning smell. The yellow engine light went on in the dash. So when this happened, I immediately stopped the car and had it towed.

What do you guys think this is?

I have consistently changed the oil on this car, usually every 5-10,000 miles. The most recent oil change was 2,000 miles ago. According to the dash, I have adequate oil. So is this an oil problem?

What I have noticed is that for over 1 1/2 years, there was a burning smell, probably from the rear vents, after I drove and then parked the car, but everything worked perfectly. Any advice would be greatly appreciated. Thanks!

No HTwo O

Do you have a 987 or a 997? Year? Mileage?

AOS is my guess.

Macster

AOS is my guess too.

My advice is to relax and let the warranty happen. Reads like you're doing alright by your car but even so the AOS will fail. It happens.

As for the smell, that's pretty normal. I can say this because had there been any leak I think you'd know it by now.

The large areas of the engine and other underneath car parts are coated with cosomline and it takes some heat cycling before this drops off some.

The car is of course new and the various plastic and rubber pieces are all new and will emit a stronger odor that will taper off as they age.

Then you have to consider that after a drive of any time/distance there's a lot of hot engine, wiring, rubber, exhaust, drivetrain and tires just behind the cabin and when you get out the smell can be quite strong.

Just take a deep breath and enjoy the smell of your new car after a nice drive.

Sincerely,

Macster.

caunyd

Guys thanks for the response. Unfortunately, my car isn't close to being new. it's a 2006 Cayman S with 72,000 miles on it, as my daily driver. So no warranty.

I had my neighbor who is a mechanic look at it, and he seems to agree with you guys. He thinks it's the oil separator.

Any other guesses or suggestions as to what the problem might be? Thanks again.

Macster

AOS is a pretty good guess. These have failed in enough cars the symptoms are pretty well known.

FWIW, at 77K miles your car is about where my 02 Boxster was when its original AOS failed.

The risk is if continue to run the engine, try to find some other cause, if it is the AOS the AOS can get to the point it can cause enough oil to be routed to the intake to cause the engine to experience hydraulic lock with possibly disasterous results to the engine.

(Concurrent with my car's first AOS going bad the service manager told me of another owner who didn't want to drop the car off and wait for the parts to come in and instead insisted on continuing to drive his car. The AOS failed to the point his engine suffered a hydraulic lock. I played it safe and didn't even drive the car to the dealer (over 40 miles away) but had it flat bedded there. As a result my car's AOS was replaced and the car has now covered another 170K miles with no apparent after-effects. Might mention the engine is now on its 3rd AOS.)

Either you trust your mechanic or you don't. If you don't then you seek out one you can trust and let him identify the cause of the symptom. If it is not the AOS he'll let you know.

If you insist on other possible causes... without knowing the error codes associated with what I assume the warning light (CEL) was it hard to make any reasonable guess.

About all I can think of is if the 'smoke' was not smoke but instead water vapor then there can be a coolant leak. A head gasket, a cracked head or even a cracked block/cylinder.

Given the above and an AOS, I hope it is an AOS.

Regardless, let a professional diagnose the cause of the behavior.

Sincerely,

Macster.

CW-VIESOCK

I bet it's the AOS as well. Sure fire check to tell if it's going kaput is to pull off the hose from the top of the AOS (upper right rear of engine) that connects to the intake manifold. If it has enough oil to coat your finger, the AOS has died. Did a search for a pic for you and RennTech had one with replacement info. Just do search in on here for AOS replacement. My link wouldn't take.
Good luck...

orthojoe

My friend with a 2000 boxster S had the same problem. It was a relatively inexpensive fix, considering the other possibilities.

caunyd

I tried to remove and replace my air oil separator, but I couldn't do it. So I haven't turned on the engine since. So I had the car towed to the mechanic, but now I notice an oil leak, which I never noticed before. Even when there was first white smoke, I checked the oil level, and it was full. Can removing the AOS, without replacing it somehow cause oil to leak?

caunyd

I think the oil leak was because of the bad air oil separator allowed too much oil to get into the cylinder/piston. So I replaced the air oil separator. But after I replaced the AOS, I tried to start the engine, but it wouldn't start. It just made a "click" sound. At first I thought it was a battery problem, but then I charged and then jumped started the car, but it still wouldn't start.

My thinking was that perhaps too much oil went into the cylinder/piston. The engine won't start because now the piston was trying to compress oil, which is an incompressible liquid. I think this is what they call "hydraulic lock." So I tried to take out all 6 spark plugs to allow the oil to drain out. Sure enough, after I removed the 5th spark plug, oil drained out. After removing all 6 spark plugs, I cranked the key for several seconds so that the pistons would pump out any additional oil in the cylinder. Then, I replaced all 6 spark plugs.

After doing this, my engine was able to start again, but there was still the initial white burning smoke, but a lot less of it. So then I figured there was still some oil residue in the engine, so I stepped on the gas, and had the car at 3,000 rpm for a few minutes to try to get rid of the oil residue. After doing all this, the burning white smoke has stopped, and I believe my problem is fixed. However, now I'm getting the error message "take to the engine shop." I think that the problem is solved, but now, because of oil being in the engine, perhaps some sensors have been damaged, and therefore I'm getting this error message, even though I think that everything is ok now.

Why do you think I'm getting this error message? Do you think I did anything wrong? Can you guys make any suggestions or give any advice?

CW-VIESOCK

[QUOTE= Can you guys make any suggestions or give any advice?[/QUOTE]

I cannot give you an answer but commend you on your persistence and determination.

Marine Blue

I would bring it in to a Porsche tech and have the code pulled to determine the cause.

You may also find that the code may clear itself after a few start/stops.

Macster

You dodged a bullet.

You need to be able to read and then post the error code(s).

With an error code or codes more specific help can be given.

In this case, I can only offer some ideas...

The check engine light on can be 'normal', a side effect from the load of oil that was passed through (in liquid and vapor) the engine.

When my my 02 Boxster's first AOS failed the engine smoked heavily at the end -- when I had to start the engine to position the car for the tow truck (and managed to get the car stuck in the snow in the driveway...).

After the dealer replaced the AOS the manager told me the check engine light was on. He said it often is after an AOS failure due to the effects of the oil from the failing AOS. I had at the same time as the AOS was done the plugs changed (just to be safe) and the oil/filter service done. I was out of town so I gave the manager permission to drive the car and he drove it maybe 50 miles but the situation was not much better.

When I got back I picked up the car and as I was taking a new job halfway across the country I put the car on a trailer behind a moving van and hauled it to sunny CA.

After a few weeks I got settled in and could focus on the car again. The car was running fine but the CEL would come on once in a while. It took some amount of driving though. Oh, the error code pointed to an O2 sensor.

Long story short I finally was able to 'time' the CEL and managed to view the sensor in question and spot the behavior that prompted the error code.

I then had the dealer replace this sensor and the error code stopped appearing. Had I not been out of work for some months prior to this I might have just replaced the sensor, both sensors in fact based on the error code. But I was a bit cautious about spending money (even though thankfully being out of work was not a financial hardship it still worked to make me spending adverse for a while.)

Whether the sensor failed from the oil bath from the failing AOS or it was just the sensor's time to die I can't say. The same sensor on the other side lasted considerably longer so I have to think the failing AOS had a role in the sensor's 'early' demise.

You must know the error codes.

As long as the engine is running ok otherwise, and not making any scary noises, what you can try is this: 1) Remove and clean the TB. This can get quite oily from a bad AOS and an oily TB can cause rough running, varying idle, and so on. Be sure you handle the TB with care and reinstall it without any *intake air leaks*!; 2) If the plugs are questionable replace them; 3) Run a bottle or two of Techron though the gas tank. Follow the directions on the bottle. After you run the gas tank down to the point you have to refill it after the last bottle of Techron then change the oil/filter.

(Yet another possible source of the error code not from the aftereffects of the AOS can be a leaking oil filler tube cap. At idle check for any play of the cap and listen for any noises from a leak around the cap.)

The above can help undo the effects of the oil from the AOS. A clean TB, fresh plugs, and a fuel system cleaned from tank to injectors to intake valves to combustion chambers to sensors to even converters can only help things.

But if at anytime the engine starts to act up, run rough, exhibit any signs of distress, shut off the engine first and ask questions later.

But the odds are what you are seeing from the engine is just the aftereffects from the failed AOS with the possibility there maybe a failing sensor.

My motto is there is aways two problems, unless there is just one problem, or 3 or more problems...

Sincerely,

Macster.