jvaski

Sorry to do this one more time folks....
My 2001 Boxster has 53K Mi on it and it's for sale.
It occasionally smokes a little oil very briefly and has a very brief liftersrattle on cold start after sitting for days or weeks.
The original owner broke it in with 15/50W oil in warmer climate up to 30K Miwhen I brought it to cooler climate and changed to 10/40W Mobil 1 Synthetic.
Now that I'm selling it I want to go back to the owners manual recommended15/50W Mobil 1 to hopefully give a new owner a quieter cold starting experiencewith less frequency of blue smoke puff if left for extended periods.
(It's really difficult to explain to a buyer that occasional blue puff andlifter rattle is normal on cold starts after extended non-use)
Anyone have any comments on this stupid re-hashed issue ?

Schnell Gelb

Does the 15-50 make actually the engine quieter in your experience?

jvaski

I would imagine switching back to 15/50W will keep the lifters from draining down as fast - thus reducing the light rattling they make sometimes after the car sits for weeks ....."quieter startups"

jvaski

"quieter" cold start-ups after the car sits for long periods - because the lifters wouldn't drain off as fast (hopefully)

Macster

While it is unfortunate the owners manual indicates 15w-50 or even 10w-40 are suitable oils to use they are not on the Porsche Approved oils list. IOWs, the owners manual is wrong.

A brief bit of start up clatter -- lifter/chain -- is normal for these engines. If a prospective buyer is seeking a car with an engine that is quiet at cold start he probably shouldn't be looking at a Porsche.

My advice is to do an oil/filter service and use an approved oil with a suitable viscosity index (0w-40 if it gets cold (-25C) where you live/drive, or 5w-40 otherwise) for your location. If you want add two bottles of Swepco 502 oil improver. The Porsche techs tell me this stuff helps to quiet engines that are used infrequently.

Regardless if you use Swepco or not, the engine with the fresh oil will be as quiet as it can be at cold start.

If possible while you have the car for sale using the car every so often to keep it from sitting unused a long time between showings may be worth the trouble.

jvaski

Yes Thank You - I've seen the Porsche Approved Oil List. I recall the Dealers recommending 0/40W beginning around 2005 forward. They claimed there was a valve-train lubrication issue in Boxsters that demanded it.
My concern is the car was run with 15/50W through 30K mi ( all the Porsche shops were using that weight for warm climates )
So, I'm concerned that going to a Porsche Approved light oil like 5/40W in summer will enhance the cold startup blue puffing.
Always been skeptical of using additives since the day I drained a motor working as a car mechanic and saw literally jello like stuff fall into the drain pan. It was early synthetic with an additive.
Maybe leave the 10/40 that's in it and let the next owner figure it out. I agree with your idea of simply making sure it's run every day or two while selling it .

Macster

My dealer was using 0w-40 for my 2002 from "day one". The oil was in short supply though over the counter, so to speak. The dealers were buying it in bulk from PCNA.

The bit of smoking is not oil related unless the oil has big miles on it. (Both of my car engines are more likely -- though it is still rare -- to smoke upon startup when the oil approaches 5K miles. I change the oil every 5K miles.)

The smoking is from starting the engine then after just a few minutes shutting it off again. This smoking is quite common with used and even new cars on the Porsche car lot because these get started and run just a short time then the engine shut off again.

(When I was shopping for a new Boxster when it was time for a test ride/drive the salesman started the engine and the engine emitted a bit of oil smoke. Later when I was back at the dealer at what would prove to be my successful (albeit 2nd) attempt at buying the car I had the salesman start the engine again. No smoking. But we had driven the car some miles just an hour or two earlier.)

Using a Porsche approved oil ensures among other things that 1) The proper type and viscosity of oil is used; and 2) the proper additive package is present to afford the engine the best protection.

If during a showing the engine smokes a bit upon start up -- and like the techs tell me as long as the smoking event is brief, ends almost as soon as it starts, if the engine doesn't manifest any untoward behavior, if the CEL remains dark -- and if the prospective buyer questions the smoking you get to repeat the well worn phrase "They all do that." But in this case it is true.

jvaski

Thanks Macster, This car has always run great and only smokes very briefly when I let it sit for many days or weeks. I get a little very brief lifter rattle along with it until oil pressure resumes.
It has never used oil as far as I can tell and the plugs looked really clean when I changed them a while back. The car is warm weather summer used only here in the mountains.
Having been a foreign car mechanic previously I can live with these typical quirks. I believe that because the engine is a flat pancake style it's prone to a little seepage past the rings when sitting for long periods.
What ever the case may be I'll explain this very briefly to whom ever buys the car and they can either believe me or not.
Thank you for your comments - it's more reassurance that "it's the nature of the beast" to see a little blue puffing.

Macster

Not past the rings.

The oil for the smoking comes from the oil vapor the AOS allows through. This stream of crankcase fumes/gases with oil vapor is routed to the intake manifold.

The heavier oil vapor can't make the sudden/sharp turn and impacts the intake wall opposite of where the hose from the AOS attaches. On this wall then the oil vapor collects/forms back into a liquid. As long as the engine is running any oil then gets burned and because the engine hot there is no smoking.

What happens is when the engine is shut off any oil that has collected on the intake wall then has a chance to drain down and colllect on the closed intake valves of a cylinder or two. Or if the valves open drain into the cylinder.

Upon the next cold start this oil is not completely burned and smoking is the result.

It is unfortunate this smoking happens but in some ways understandable. These are DOHC engines and relatively high revving. The two cams (per head) require considerable oil for both their bearings and lobes. Four valves per cylinder means 4 lifter buckets that require considerable oil to allow them to maintain sufficient oil pressure to keep the zero lash hardware working and to properly support the bucket and allow it to move up and done in its bore with zero wear. The oil that seeps out from around the lifter bucket then has to help lube the bucket face and the cam lobe. This oil alone puts a considerable amount of oil under the camshaft covers. (The oil scavenge pumps -- one under each camshaft cover -- really earn their pay.)

Then add in the oil that bleeds out from the cam bearings and then the considerable amount of oil that is routed to the cam chains and carried up and slung off as the chains make the sharp turn around the exhuast came sprocket and the chain the exhaust cam drives the intake cam makes two sharp turns and the space under the camshaft cover is at especially higher engine speeds quite full of oil and oil vapor.

In some ways it is impressive the AOS is able deal with this huge volume of oil vapor (at times the total volume of oil in vapor form can be several quarts with most of it under the cam shaft covers) at some acceptable level.

Byprodriver

I would venture to say (all the Porsche shops that know little to nothing about Water-cooled flat-6 Porsche engines)