Connect the dots: White smoke, Oil in coolant hose, misaligned camshafts, plastic in sump, large and curly aluminum flake in coolant line, leaky/broken water pump

[Tarek]

Greetings 996 gurus!

 

'03 Carrera 2 Cab, 6 sp.  152,000 miles.  Owned it since 40,000 miles

 

Please bear with me, for the benefit of setting the background and facts straight:

• This started with a suspected AOS issue, based on the crazy puffs of white smoke, and lingering small amount of smoke afterwards, along with very strong suction at oil filler tube cap.  (Sorry it wasn't measured scientifically), and dropping oil pressure when warm.  At idle, it would shut off eventually, just as it gets warm and as oil pressure dropping.
• It coincided with a leaky coolant tank and bad water pump
• Checked oil sump and found 2 small brown plastic pieces.  Im thinking these are camshaft chain guide pieces.  Elongated, 1 mm thin, roughly 10-11 mm long, and may be 2-3 mm wide.  See pic. No visible metal shavings or powder or anything sticking to a magnet
• Found oil seeping at the bellhousing/engine parting line.  Now please don't sentence me to Porsche jail just yet, but I'll understand if you do.  IMS and RMS are still original.   Kept waiting for the clutch to go to do it all at once, but the darn thing has been perfect for the last 110,000 miles! (Still within spec, actually!!).  Found the IMS to be leaky.  No oil seepage from RMS.
• 3 composite fins on water pump are broken
• Zero history (and still none) of metal flakes in oil filter or sump.  Only 2 small brown plastic pieces newly discovered in sump.  No metal
• Oil is certainly not contaminated with coolant
• No chain rattling noises that I could tell

• Oil dripped out of the vertical coolant line, at the exit of the oil pump console.  Small amount.  Nothing frosty.  Just a small amount of black oil.  No oil anywhere else in the coolant system.  I'm thinking there will be more of it collected in the bottom of the oil pump console, on the coolant side.  Vacuumed everything meticulously

• As I vacuumed all coolant lines (and engine ports, the best I could), in my failed search for the broken water pump plastic, I retrieved a rather large piece of curly aluminum (non magnetic) shaving from the large coolant hose (that was connected to the oil pump console).  Basically it came from the radiator end.  I'm thinking this broke off either from the oil cooler, (which could explain the small amount of oil in the coolant line), or from one of the radiators.  I haven't put together a pressure testing jig to pressure test the oil cooler to confirm, yet, but it's coming.  Any other thoughts? Picture attached

• Old AOS holds vacuum perfectly from one of the smaller ports, and has a tiny leak when vacuuming from the other port.  New AOS holds vacuum perfectly regardless of where you pull vacuum from 

 

Because of my back injury, and since I'm not a contortionist to start with, I decided to drop the engine/tranny to check everything and tackle the tasks at hand, that include IMS bearing replacement, RMS replacement, checking/replacing timing chain guides, replacing coolant expansion tank, replacing AOS, and chasing whatever else needs addressing

 

An issue came up in the process of prepping to tackle the tasks at hand:

The camshaft alignment tool is not lining up perfectly for locking the camshafts on bank 1.  I could push one end of the tool sideways with my thumb and flex it enough to barely catch onto the intake camshaft groove with the help of a tap with a rubber mallet, but it just rubs me the wrong way that I have to do that.  It's basically off by a hair.  I weigh less than 150 lbs and was able to do that with my left hand (I'm right handed), so it's not an excessive amount of push, though still need the tap of a rubber mallet.  Issue is the same when rotating the engine an additional 360 degrees, or when trying it on bank 2.

Should I loosen up the bolts on the cam sprocket to make this small adjustment before proceeding, or should I proceed to replace the IMS bearing with the current, less than perfectly fit lock on the camshafts?

 

This all may make a great story on how some of these events are either connected, or randomly coinciding.   But in the mean time, I'd like to know if it's ok to proceed with the IMS bearing replacement, knowing the camshaft alignment tool is not as perfectly fitted as I'd like, without help.  Or should I make a small adjustment by loosening the bolts on the cam sprocket(s).  Of course I plan to remove (and replace with new when done) all 3 tensioners as I move on to check chain guides and everything else.  Just want to make sure there's no play in the IMS shaft as I rotate the engine to do other work, therefore I'm thinking that needs to come first

 

Apologies for the long post and thanks in advance for any insight or suggestions you may have

 

 

 

 

Edited September 27, 2021 by Tarek
typo