Scavenge/secondary oil pump removal questions

Car is a 2001 996 C2 From what I understand, the left(driver side) cylinders is "Bank 1", and the scavenge pump should be oriented with the 1-3^ towards the center or inside of the engine. Bank 2, or the passenger side of the engine should have the pump with the 4-6^ facing towards the center of the engine. Assuming I have this correct, my pumps are facing the wrong way. 1: Are the scavenging pumps identical for each side? 2: If the pumps are identical, do I simply need to loosen and rotate the pump to face the proper way? 3: If not, and they need to be swapped, are there any special procedures with cam timing or such to removal and replacement of these pumps? These are probably pretty ignorant questions. I apologize for that, but I could find definite answers with searches. Thanks in advance for any help or advice.

The stamp 1-3 for bank 1 (drivers side) should point to the crankcase (center of engine). Both scavenger pumps will have 1-3 on one side and 4-6 on the other and are interchangeable but the orientation needs to be correct. Which raises the obvious question, what is the background for how and when you noticed this? Was work just done to the car? Just purchased? How long was the engine run with the pumps reversed? As far as swapping them. The pumps can be extracted by removing the 4 bolts holding them in. I'm not sure if you have clearance to remove bank1 without also taking the cam cover off. I only say that because the only manual I have available to me right at the moment says bank 1 cam cover has to be removed but it doesn't for bank 2. And I can't picture the clearance for bank 1 from memory. If you do have to take the cam cover off, you need to have a cam hold down tool (people have done it without but you run the risk of breaking the cam. You wouldn't be changing anything on the timing however. Someone with more experience than me can hopefully help more. You should give us some background though on how this could have happened.

On my .2 motor I was able to get the bank 1 pump off by dropping the motor down a bit. It was finicky but doable. Bank 2 should take about 3 minutes to fix.

No need to remove the scavenge pumps if oriented wrong, just remove the bolts and rotate 180* and re-install bolts, torque to specs.. Yes, we would like to know how long the engine was ran this way, and how it got that way.......( the interesting stuff ya know ) ..

Thanks, you guys are awesome. I rotated the pumps, and went from 2 bar oil pressure at 3K and higher RPM, and a loudly ticking right cylinder bank, to 4 bar at 3K RPM without ticking. As far as the interesting stuff goes, I'll preface it by saying I'm the poster child for what not to do when buying your first 911/996. Short version I purchased the car in January 2022 with 158,000 miles, IMSB, timing chain guides, and clutch were said to have been replaced around 157,000 miles, and if I recall correctly records confirmed this. I ended up putting 2,000 miles on it with the scavenging pumps backwards, so assuming they were improperly installed during that last service, the car has been this way for 3,000 miles. Who knows how much damage I caused, or when it will show up down the road. Long version I wasn't smart enough to have a PPI done, and I was too distracted by the experience of driving my first 911 to notice the oil pressure during the test drive. I didn't notice the ticking for a few days, but then noticed the low oil pressure as well. This is another point where I should have had it towed to a shop and checked out, but I'm poor, could barely afford the car, and didn't want to spend a few hundred on a tow to the nearest porsche shop only to find out I needed to spend another $10-$20K on an engine or rebuild. I spent a lot of time here reading about bore scoring, and clogged oil intakes, dropped the sump, cleaned out a bunch of what I believe were timing chain guide pieces. I bought a cheap bore scope, but gave up on checking for bore scoring after about 30 minutes of failing to get a decent look at the cylinder walls. Sealed the pan back up, fresh M1 5W50, same ticking, same oil pressure. So now I have to decide what to do. I could sell the car as a roller, maybe get $5K back, spend $15K on a used engine and hope it was better, or try to enjoy the car till the engine blew and LS swap it. I was too scared to trust a used engine after all the bore scoring threads, I just can't afford to put several $15K engines in the car if it comes to that. So I figured I if I was going to sell it as a roller, I might as well drive it while I could. Turns out I enjoy the car so much I didn't want to let it go at all, so I started to collect parts for an LS swap, since I figured that would be the most reliable in the long term. The recent "Oil pressure and ticking" thread, together with another thread I found, led me to check the scavenge pump orientation, and discover the problem. I don't know if I've made every mistake possible or not, but I have immensely enjoyed owning and driving this car, and hopefully will for years to come. Thanks again for the help.

OP - Just spitballin’, but did you get pics of the reversed pumps before you reoriented them? Do you have paperwork that shows when the pumps were removed? Oil pumps are a pretty big deal. ANY shop, Porsche specialist or not, should not screw that up, especially when the silly things are marked to keep dopes like me from swapping them. What would I do about your current engine situation? Put a couple thousand miles on it and get a UOA done. Just be cognizant of the fact you’re likely to see high silicon after putting sump plate back up. The important numbers will be for baseline internal engine wear. If you have a scanner that reads cam deviations, check those. Note your oil pressures at rpm checkpoints when the engine’s warmed up. Things like that. Quite possible you’ve not badly harmed the motor. Skip would have a better idea than any of us about what your mechanical outlook, is going forward.

Oil pressure when warm is about 3.5 from 2,500-3,000, and around 4-4.5 at 3,000 and up. Checked the cam deviations on a fully warmed engine this afternoon, Durametric showed 1.64 and -6.48

Kinda looks like the motor needs to be opened up again again. The -6.48 number is real close to setting a code but the bigger issue is the delta between the two numbers. Not great news but at least it can be inspected and double checked since u already found 1 giant issue. Also oil pressure numbers look pretty good.

Thanks for the input. How concerned would you be? The camshaft deviation just shows wear on the chain pads, or does it indicate something else as well? Is this something I can monitor regularly, or get checked ASAP?

Generally the high numbers r a function of wear to the variocam pads which r replacable but at a high labor cost. Beyond that it would be stretch in the lms to cam chain. That requires splitting the block. U can cheat the cam gear some to compinsate for the stretch but its a trial and error proceedure. My concern is someone has been into the motor and if they did not pay attention to the position of the scavange pump, what else dis they screw up? At this point the motor is technically in spec so its safe to drive but its kinda at the edge of a tossing out a cel.

I had -4 and -2 before my shop replaced all four tensioner pads. Afterward, -1 and 0.

Quotes source post: 18464585

Technically, chains can�t stretch, they wear at each pin minutely at every link. This wear increases with uneven load distribution along the span of links as they engage the teeth. 3D force (twisting/swiveling) force on a chain is bad, as De Jeeper highlights. �Damaged� chains jump timing.

Quotes source post: 18464585

Ditto!