Another engine problem. Please read

[niceguy]

I have owned my Boxster for less than a year. The car has roughly 30000 miles on it

Oil and genuine filter change every 3000 miles with Mobil 0-40

Car is completely stock, always warmed up before rev over 4k rpm, never rev past redline

Symptoms of mmy 2003 2.7 Boxster Tip (In chronological order)

1. Rough idle, higher than normal engine rev at idle

2. Huge amount of Continuous, Steamy White smoke from exhaust while driving (like smoke grenade)

2. No overheat after limping 6 miles home, coolant stayed around 82-3 C, No CELs

3. Loss of 0.5 L engine oil

4. No engine oil or coolant on the garage floor

5. Loss of power with some occasional ticking sound. Thanks

Please help to diagnose the potential problem as it doesnt look like a AOS.

[wvicary]

Sounds like a AOS to me.

[spyder803]

Agree. from what I've read that is your AOS. There are several detailed posts and write ups online on changing these. Looks like it takes some time but is relatively simple.

[niceguy]

Agree. from what I've read that is your AOS. There are several detailed posts and write ups online on changing these. Looks like it takes some time but is relatively simple.

Thank you for the replies guys. I sincerely hope that it is AOS. I did a search on AOS last night and spent an hour or so reading it.

My car did not throw a single CEL light. And it does not only smoke during start up. Instead, it is smoking almost most of the time except when the car was on the highway doing over 60mph. As soon as the car had to be slowed down at a junction, the smoke became awfully large and alarming.

To be honest, engine oil was filled up a touch too much. Now, the electronic oil measurement on the dash is showing 1 box less than full.

Any ideas guys? I plan to open up the engine the cover tonight when I get home and see if the throttle bodies and the hoses involved are full of oil.

One more thing, due to the local temp here can reach as high as 35deg, I poured in 6 quarts of Mobil 1 0-40 and 4 quarts of 15-50. Will this be the problem?

Edited March 26, 2009 by niceguy

[1schoir]

Agree. from what I've read that is your AOS. There are several detailed posts and write ups online on changing these. Looks like it takes some time but is relatively simple.

Thank you for the replies guys. I sincerely hope that it is AOS. I did a search on AOS last night and spent an hour or so reading it.

My car did not throw a single CEL light. And it does not only smoke during start up. Instead, it is smoking almost most of the time except when the car was on the highway doing over 60mph. As soon as the car had to be slowed down at a junction, the smoke became awfully large and alarming.

To be honest, engine oil was filled up a touch too much. Now, the electronic oil measurement on the dash is showing 1 box less than full.

Any ideas guys? I plan to open up the engine the cover tonight when I get home and see if the throttle bodies and the hoses involved are full of oil.

One more thing, due to the local temp here can reach as high as 35deg, I poured in 6 quarts of Mobil 1 0-40 and 4 quarts of 15-50. Will this be the problem?

Those oil viscosities combined would not be the cause of this problem.

Let the engine idle and try to unscrew the oil fill cap. If it takes a serious amount of effort, that, combined with the other symptoms that you have described definitely point to a failing AOS. An AOS will not only cause smoke at start up but will continue to smoke while the engine is running.

Take a look at the photo on Mike Focke's website, here : http://mike.focke.googlepages.com/airoilseparatorreplacement

That will also give you a good idea of what it looks like and whether that's what your smoke condition looks like.

Regards, Maurice.

[niceguy]

Hi Maurice,

Thank you for your reply and nice to meet you.

I will try that as soon as I get home tonight. I am keeping my fingers crossed until then.

With a serious amount of effort to open the oil filler cap, but it can still be opened, right? How long do I have to idle the engine before trying to open the cap?

Would mixing oil viscosities on Mobil 1 be a good thing for hot weather?

Best regards,

Boris

Edited March 26, 2009 by niceguy

[niceguy]

Hi Maurice,

Thank you for your reply and nice to meet you.

I will try that as soon as I get home tonight. I am keeping my fingers crossed until then.

With a serious amount of effort to open the oil filler cap, but it can still be opened, right? How long do I have to idle the engine before trying to open the cap?

Would mixing oil viscosities on Mobil 1 be a good thing for hot weather?

Best regards,

Boris

As soon as I got home today, I checked and made sure there were no engine oil droplets in the coolant before I opened the engine cover and unpluged the Y-shaped hose connecting between the AOS and the tubing to the throttle body only to find some drops of oil present. So, I used a wooden cock to plug the hole on the throttle body side and placed a rag on the opened AOS end. Immediately, the car idled smoothly without increased idling rev. The engine now revs with power and on longer consume any engine oil. I drove around the carpark at slow speed for about 15 mins to allow all the oil that was sucked into the engine to be burnt off along with the white smoke. After about 20 mins, the engine reached normal operating temperature and all the smoke was completely gone.

Am I right in thinking that all I have is an AOS problem and not a cracked head or anything serious? I have already ordered a revised AOS from P.centre and it will be fitted by an independent garage tomorrow. Am I doing the right thing? Are there any other maintenance jobs that I should do while I am at it?

Thanks a lot every one and RennTech

Edited March 26, 2009 by niceguy

[Jake Raby]

Is this smoke oily or steamy?

Oily smoke will foul O2 sensors and generally throw a CEL, steamy smoke will not.

I have had 5 experiences just like this, 4 were cracked heads and one was a blown exhaust gasket that allowed the watercooled exhaust ports to dump coolant into the exhaust where it created steam similar to that of a blown head gasket or cracked head.

If the smoke isn't oily, it can't be the AOS.

[niceguy]

Is this smoke oily or steamy?

Oily smoke will foul O2 sensors and generally throw a CEL, steamy smoke will not.

I have had 5 experiences just like this, 4 were cracked heads and one was a blown exhaust gasket that allowed the watercooled exhaust ports to dump coolant into the exhaust where it created steam similar to that of a blown head gasket or cracked head.

If the smoke isn't oily, it can't be the AOS.

Thanks Jake for chiming in with your wealth of experiences.

No CEL, no coolant mixed with oil, no overheating. The white smoke I got lasted quite for quite a while in the air. To me, it stayed in the air much longer than vapor. It didn’t smell intrusive like the coolant I had smelt on another car. Instead, it smelt a bit like some very fine tobacco. What I also found was the steam seemed to have left some oil residual on my rear apron under the rear bumper. Is this oily smoke that you are talking about?

[niceguy]

I have an update for every one.

As of today, I have changed to a new AOS unit. After driving for about 30 miles on various types of speeds and roads, the smoke has completely gone away. Furthermore, the car drives perfectly with no strange noise, loss of oil, power, rough idle and etc. I'd say it feels just like new. But, to be honest, I'm still haunted by the thick smoke incident only a couple of days ago. Is there a way that I can make sure my car has only got a faulty AOS unit and not a cracked head problem?

[phillipj]

I wouldn't worry. If you had a cracked head you would know. Probably with water in your crankcase.

Another happy AOS story :clapping:

:cheers:

[niceguy]

I wouldn't worry. If you had a cracked head you would know. Probably with water in your crankcase.

Another happy AOS story :clapping:

:cheers:

That's just so reassuring to hear. Thank you for all the support and RennTech.