Boxster smoking

[CharlesBanbury]

Good Afternoon,
I have a very early 2.5 Boxster 1997. If I move the car around without taking it for a proper run it smokes badly on a subsequent startup. If, however, I just start after a decent run it doesn’t smoke at all. It doesn’t smoke under load and doesn’t smoke at any other time only if I move it around the drive without a blast down the road. AOS?
many thanks,
charles.

 

[Motorhead]

Charles,

Are you sure it’s actually smoke rather than just condensation build-up from just moving the car around being burnt-off? If not the cause then a failed AOS can produce a significant amount of white-ish smoke at idle.

Jeff

 

[CharlesBanbury]

Thanks Jeff,
it’s oil smoke I think. The car is having a service next week so I will charge the AOS as it’s probably never been done. is there anything else that I should charge that’s not on a normal service schedule? It’s a very basic and very early car if that makes any difference.
many thanks for your time.
charles.

 

[Motorhead]

Charles,

I don’t know how many miles you’ve done but I would just stick to the recommended service based upon mileage and time. In addition to changing the AOS, if the plugs haven’t been changed for a while it would be worth doing that if only to make sure that they can be removed and that the coil packs in particular are in good condition as they’re items prone to degradation and ultimate failure … just when you least expect it! If the engine cover is off to replace the AOS, you may want to replace the air filter too if it’s not been done for a while.

Also it would be worth checking the poly-belt for damage and cracks. If you decide to remove it you’ll also be able to check that the coolant pump and other ancillaries and belt tensioner are all OK.

As always, it all depends upon how much time and money you’re prepared to invest. []

Jeff

 

[BrianJ]

Occasional white smoke (and lots of it!) has been an enduring 986 mystery since they were introduced. Lots of theories but as far as I have ever seen, no convincing explanation. I had mine from new and probably in the 80,000 miles I put on it in 6 years, it did it maybe 2 or 3 times in the first few years, usually in exactly the circumstances you describe. I also had a couple of instances where after backing out of the garage and immediately shutting down, it would then turn over but not restart unless I left it for a few hours (a bit like a 1950s carburettor flooding episode). As my servicing OPC could never find anything wrong (even once trailering it to them when it wouldn't start) my own conclusion was that there was something about the fuel system electronics that didn't like that sequence of events. After that, I always ran the engine long enough for the initial fast idle to reduce to normal before shutting down, which appeared to resolve both problems. I never had the AOS replaced on that car.

 

[CLIFFWILKINS]

It's pretty normal on start up some do it some don't on start up especially if its not been used for a while or in your case started up briefly to be moved.
If the smoke clears after 20/30 seconds I would not worry.

 

[CharlesBanbury]

Many thanks everyone. I have bought an AOS unit and my mechanic is primed to fit it as part of the service. The car has been practically unused for a number of years so I am asking the mechanic to go through everything very comprehensively. I will report back if this cures the smoke issue. When it happens, it’s quite a sight!!
with regards,
charles.

 

[BrianJ]

When it happens, it’s quite a sight!!

Yes, when mine did it, it filled the garage and our quite large front garden with a slowly drifting cloud of thick white smoke. Like somebody had lit a smoky bonfire. Embarrassing.

 

[Peter_Bull]

When it happens, it’s quite a sight!!

Yes, when mine did it, it filled the garage and our quite large front garden with a slowly drifting cloud of thick white smoke. Like somebody had lit a smoky bonfire. Embarrassing.

Thats happened to mine Brian, luckily it failed when they were taking it off the ramps at the OPC after a service! Filled to entire garage with smoke. 10 mins later I would have been on the road in the dark and would not have noticed it!

 

[911hillclimber]

The following words are based on my own experiences, but the engine is a 2009 2.9 between 50K and 65K miles.
1
If I just start it to move the car down the drive the cold start fuelling is still working, shut the engine off.
Next day, re-start and the engine will start again on the cold start still being 'rich' from the previous day. Smoke can erupt but NOT the HUGE white cloud. most times nothing comes out of the exhaust like smoke of any colour. Do this short cycle more than 3 times and some black rich smoke might erupt, gone in 15 seconds.
2
If the car is used, short (20 miles) and long(100+ miles) it might randomly erupt the massive white cloud on cold start up, usually outside a crowded hotel with people everywhere...
I changed the AOS twice (different design but same principle to the 986). This did NOT cure it happening at all, but read on:
3
Last service my Indie slightly underfilled the car (2 empty segments showing, dash indication only). It is usually one segment empty to the manual.

Result was ZERO white smoke. This has been the case for 9 months now where it normally would have erupted at least 6 times.

In my experience the white smoke is due to the engine oil level being too high saturating the AOS and overwhelming its function.

Now you have the AOS get the poor mechanic to fit it, he will love you for the opportunity, but on re-filling the engine keep away from the Max mark on the dip stick.
I believe the white smoke is neat oil getting to the inlet tract. It is normal for fine oil mist to get to the tract, it is where the AOS vents the mist after all, the neat oil separated from the heavy mist from the engine crank case runs down to the case/sump after the mist is collected and condensed by the AOS (air oil separator doing it's job).

Anyway, after 18 months of worry this has been the result.