987.2, old problem returns, but I was ready!

[911hillclimber]

Thought this tale might help a few on here.
My 987.2 is a 2.9/2009 Gen 2 car and in the past plagued me with the usual alarming white smoke antic.
Through Laure on here for a year now I've run the engine with the top 2 segments 'empty' on the dash dip stick (whoever removed the dip stick should be banned).
No white smoke on cold start etc.
This proved that (on this car at least) having the level showing full, ie just the top segment empty will induce white smoke.

Took the car today to the ever reliable Zuffenhaus for a minor service ahead of a good Euro Trip.
Chris is well aware of this car's 'condition' and refilled with Mobil1 to top 2 segments empty and took the car for a short test run. All was well.
I get in it to go home and within 10 yards the white smoke was amazing, BUT would not die down, just kept on coming.

Back to Zuffenhaus and Chris checked the oil level.

FULL, only the top segment empty.
Chris drained a touch of oil out (not sure how much) and the dash showed top 2 segments empty.
Drove off, ZERO smoke. Good run home (25 miles) A and motorways, and all's well.
Decided to do a dash level check.
Engine now showing 3 segments empty!

0.2 litres of fresh oil (carried for Euro trips) and the level is top 2 empty which works. (on my car).

Will check again tomorrow to see what the dash says....

 

[johnbray]

Seems like quite a fine margin between segments.

 

[911hillclimber]

Certainly is, about 0.4L per segment, easy to over fill.

Ran the car again today.

8 mile run, so good and hot.

2 segments empty, bang-on.

Ran back home, checked it again BUT 3 segments empty!

0.2L of Mobil 1 restored to 2 empty.

Before you ask, no oil on the ground, no leaks!

Doing a good run tomorrow, so will check again.

 

[AndrewCS]

Oil level sender faulty ?

 

[Motorhead]

Oil level sender faulty ?

That was my thinking too Andrew. As always we regret not having that trusty dipstick. []

Jeff

 

[911hillclimber]

You may both be correct...

Can't change it for another 4 weeks, so fingers crossed all will be well.

Has anyone tried/succeeded in sucking excess oil out of a Boxster 987.2 using the filler hole as access to the sump?

I might have to 'drain' 0.2L

 

[Motorhead]

With modern engines without a physical dipstick I’m not sure how easy it is to drain the sump Graham. With the remote filling point on the boxer engine the route to the sump could be a bit tortuous?

Thinking back on your AOS saga, it could well be that a faulty oil level sensor has been the root cause of the problem all along. Compared with that of an in-line engine the boxer layout has a relatively shallow sump with a big surface area, so the sensor needs to be both very sensitive and very accurate to detect the addition of ~0.4L representing one bar on the electronic gauge. Add to that the fact that assessing the exact amount of oil required for a refill at an oil change seems to be difficult even for very experienced technicians and you can see where potential slight overfill situations can occur, which appear to have unwanted effects on certain engines.

Just my tuppence-worth as usual.

Jeff

 

[911hillclimber]

I think you are, as ever, bang on!

Have driven the car twice since the last level check and have made 4 checks.

Car run for over 30 miles, so good and hot, checks take around 50 seconds, about how it has always been.

First check of the 4 was one segment empty, perfect, as in no Smoke.

Second was full, again no smoke.

3rd and 4th check the day after was the same as above, all trips smoke free.

I think where the oil is when settled in the sump, hot, running the dash measure is right on the 'flip-point' of the segment change, thus i think full is actually only 'just' into the last segment, but indicates Full. Next time it is 'just' under the first segment so shows one segment empty.

The system i think is as sensitive as you (and me) think and is more an indication rather than a measure. Dip stick is a true measure imho.

In the 70's I was a design engineer working with weighing machines just taking on the newfangled Digital Age and the point where the display of weight went from (say) 28.7Kg to 28.8Kg was the flip point and tricky to program to the display.

My wife says I'm worrying about it too much (who, me?) and as she is ALWAYS right about everything in my universe, I should take heed.

I have just tried to fish a length of pvc tube (screen washer tube) down the throat of the boot filler neck but can only get 12" in before it stops abruptly.

The open end is still in the 'air' of the sump/crankcase, not the oil.

When I first bought the car from PCT I returned it complaining of the white smoke, and they never could replicate the issue (of course) but replaced an "oil switch" that had to come from Germany to cure it.

Wonder if that was the level sensor? Anyway, didn't work!

They never got to the root of the issue.

Zuffenhaus told me my 987.2 is the only one they look after that is this sensitive, and I believe them. They have been very helpful helping me.

 

[Motorhead]

Your comment about the digital flip-point makes sense Graham. With the car stationary the system requires I think about 40secs before registering a reading, so that should be sufficient time to allow the level to stabilise. The other factor of course is that the ground needs to be level to get an accurate and consistent reading.

I’ve got into the habit of measuring the level after each run. I always park at the same place on my drive and having left the engine running, by the time I’ve got the garage door open the measurement process takes only a few seconds.

I assume Zuffenhaus haven’t found any diagnostic errors associated with the measurement system but it sounds as though it might be worth replacing the sensor when you get the chance, if only to rule it out.

Jeff

 

[911hillclimber]

I do the same Geoff.

I have a set parking 'patch' on the level drive at home where the car sleeps so that is consistent. Obviously, when I arrive somewhere else the ground is not the same, hence the risk of the discrepancy.

When the car next goes to Zuffenhaus i will have them change the sensor, but will DIY if I can find it!

I have a feeling it is under the inlet manifold....

 

[AndrewCS]

Picture 1 - 987.2 - item 19 oil level sender but not shown on diagram - is installed in yellow circle

Picture 2 - 981 showing oil level sender & location

Picture 3 - 981 part numbers, oil level sender a different number to 987.2

 

[AndrewCS]

Oil level sender location (987.2 Cayman R) ...

 

[911hillclimber]

How GOOD is that!

Fantastic Andrew, really helpful.

That even looks easy when doing an oil change. I thought it would be in the oil bath from the top from the top of the case and into the oil like a fuel sender.

Makes sense down there other than talk about being in the elements!

Well done that man! []

 

[johnbray]

Can I also request a photo of oil level indicator showing what we believe is correct level to reduce likelihood of start-up smoking.

 

[AndrewCS]

From what I have read here but to be confirmed by those with a 987.2 ....

 

[911hillclimber]

As per Andrew's picture above. The segment above his yellow arrow is empty, ie black not white.

I have run my 987.2 / 2.9 at that level for 18 months and have been white smoke free during that time.

With the engine FULL then I would risk white smoke about every 10th cold start, sometimes more frequently than that.

 

[malarcy]

Agree on the physical backup of a dipstick - but I think the layout and location of the engine makes it a hard thing to plumb in and be accessible enough to be useful.

That said, for a 987.2 (and onwards) it's not actually so much guesswork with the appropriate diagnostics equipment - the car can be queried for the current level - not in bars on the display but in mm - for a 987.2 the min and max fill levels are:

→ Max. filling capacity: 72 mm → Min. filling capacity: 58 mm

That corresponds to the gauge :

The difference between the Min and Max markings is approx. 1.2 litres, i.e. one segment of the display corresponds to approx. 0.4 litres of oil.

would be interesting to know if the Indy has the equipment to read the values and compare with what the gauge is telling them.

Of course - if the level sender is faulty then these readings too are likely to be off - but with the right tools the fill level can be measured more precisely than that 0.4l range.

As far as I know the 981 onwards has additional capability in the sensor - that measures oil "quality" as well as level - and feeds into the oil change based on usage/time and I think is supposed to be more accurate than simply counting the number of cold starts and average running time parameters which the 987 uses.

 

[911hillclimber]

That is very good info for me to use with the Indie, thank you.

 

[911hillclimber]

Hope this is the final post EVER on white smoke from this car.

We are currently scooting across France on a tour, full separate report later, but had to park the car on a 20 degree slope in a hotel car park for 24 hours..

No smoke!

Have so far covered 3000Km, some runs have been 5 hours at 130km, some much shorter and slower, all on E10 and all smoke free and super smoooooth.

We were at the famous Hotal du France last night, parked in the same slot as 4 years a ago when on cold start the car belched out a white smoke cloud that enveloped the village centre.

This morning?

Nothing!

Very happy days.

lost 2 mpg using E10.

 

[johnbray]

Having just had my Cayman serviced I made sure the oil was one segment below the maximum but still get the occasional small puff of white smoke on start up.

Looking forward to the write up as we are off to France soon.