Mark White

Smokes on acceleration, and when first started. 2001 Boxster S, what worked is likely needed rebuild? Cost?

paulofto

Okay, you don't indicate when the last oil change was or if you have added oil between changes. It is obviously burning oil but do you have any leaks as well? Did you see the dash oil gauge indicate a slow use of oil or a sudden drop one day? In other words did it lose the 3 quarts over an extended period and miles or all of a sudden?

How do you know it was down 3 quarts? Is that how much you had to put in to bring it up to full? Is the dash oil level gauge agreeing with the dip stick?

To address the fix a few more details are needed before any analysis can be made.

Macster

The smoking may not be due to running the engine with the oil level low. The oil may not have been low.

Was the low oil level warning light on? The low oil pressure light?

Was the engine making any sounds that arise from low that is insufficient oil pressure and supply? The lifters tick but there can be other noises.

Have you done an oil analysis? If you can do this and it turns up bearing metal or ferrous metal in the oil and lots of it that's a sign the oil was too low and engine damage was done.

What were the circumstances of the low oil level condition? Did the driver start out with the level low? Did it go low over the course of the trip?

If it went low over the course of the trip and coupled with the smoking under acceleration and at start up that could be due to an AOS.

You or the owner of the car needs to get the car to a qualified shop for evaluation. An oil analysis. A proper check of the oil pressure. If the engine appears ok then a proper oil drain and a refill with fresh oil to then verify the oil sensor system is working properly.

Schnell Gelb

imho -Low is not the issue.
Pressure is the issue.
If the oil is low but the low pressure warning light was off, you may be O.K. The engine does not care about low if there is sufficient oil to create normal oil pressure.
It may be an oil level reading issue.
If the pressure was low for 3 hours running at light load the first audible casualty may be 'Ticking' - probably lifter tappets hammered together and creating excessive clearance = ticking. Nasty job to fix.
Cut open the filter to inspect for other damage.You won't find evidence from the lifters but you may find glitter from the bearings.
Only check oil level after many hours with the engine off(overnight) on the dip sick to be sure. If you have now overfilled it - that also creates problems. But don't worry, you,ll loose some when you remove the filter for inspection.
If you had a 2 qt.deep sump kit fitted this would not have been a problem.- for a while

Macster

The problem is not the lack of sufficient oil capacity but the failure to periodically check the oil level and especially before undertaking a drive of any distance.

And very likely the failure to notice and properly react to the presence of one or more warning lights and maybe even a warning message triggered by the low oil level.

Schnell Gelb

i said the problem was lack of oil pressure.
I did NOT say the problem was lack of oil capacity
A deeper sump just gives more latitude for error.That is clear from my Post
Please don't rewrite my comments.I have made a small edit to help

Shawn Stanford

Could it be the air-oil separator allowing oil to be sucked in on WOT?

Schnell Gelb

Yes, Mac mentioned this.
Just test vacuum at the oil filler cap = digital manometer or the 'manual' system.
And if you replace the AOS remember the 'o' rings/clips and hoses are all suspect/brittle.If you choose not to clean the plenums,it will still smoke for a while until all the residual oil is purged.
Read up on problems measuring oil level. The M96 drains slowly to the sump.And a lot of oil remains trapped in the camshaft covers for example ..