medent

I removed the oil pump from the rear end of the engine in my 2000 996 C4 and heard a snap as the IMS shaft pulled over to the right side of the hole. See the photo. This is the rear end of ther shaft, not the front end that is the subject of many discussions.
Is this normal (don't think it is)?
What is going on here? Is the recessed portion of the oil pump where the shaft slides into the guide that centers it? So do I just need to release the pressure on the right side timing chain to put the oil pump back in place and then tension the chain again? Or is there a bearing inside the block that has failed and needs replacement?
In the second photo, is this the nut I use to loosen the tension on the timing chain? Which direction should I turn it (and how much) to loosen the chain. And is there a possibility the chain will come off?
Thanks.

Byprodriver

Do not do anything! Besides reinstalling what you have removed!

Use a extra long Allen wrench in place of the oil pump shaft, thru the oil pump housing to align the IMS. This is a very tight fit so it won't be easy.
Do not rotate the crankshaft or the chain can come loose!

medent

The oil pump body and the water pump have been removed. There were signs of a minor a leakage so new gaskets were being placed while the water pump was being replaced.
The crankshaft has not been rotated.
Please describe how to use the Allen wrench?

Byprodriver

To get the IMS perfectly centered, while you press the sleeve of the oil pump housing back into the case, you need something longer than the oil pump shaft to give you some leverage. So remove the oilpump drive shaft & get a long allen wrench the same size as the driveshaft.

KrazyK

It would have been much better to lock the crank and even cams, then remove tensioners (all 3) before removing pump. Makes it impossible for anything to move.

CAUTION
•After removal of the chain tensioner, the crankshaft must not be turned under any circumstances, because otherwise the timing chain may jump over!

Removing oil pump
1.Place collection pan beneath engine to catch remaining engine oil.
2.Drain engine oil. Reinstall oil drain plug (hexagon socket a/f 8) with new sealing ring after a drainage period of approx. 20 minutes.

Tightening torque 50 Nm (37 ftlb.)

3.Remove catalytic converters See: Exhaust System\Catalytic Converter\Service and Repair\Removal and Replacement
4.Remove engine carrier. To do this, unscrew four M10 hexagon-head collar nuts (self-locking, a/f 15) and one M6 hexagon-head bolt -Arrow- . Remove engine carrier.

5.Turn engine clockwise at hexagon-head bolt (a/f 24) of crankshaft belt pulley to OT marking -Arrow- . Using special tool dowel pins 9595/1 disconnect belt pulley -see figure- . Use short dowel pin.

Information

•After removal of the chain tensioner, the crankshaft must not be turned under any circumstances, because otherwise the timing chain may jump over. Changes to the timing can result in engine damage!
6.Remove chain tensioner, cylinder bank 4-6 -Arrow- . To do so, release and unscrew the chain tensioner with a socket wrench insert (outer hexagon a/f 14).
7.Remove chain tensioner, cylinder bank 1-3 (hexagon a/f 32) -Arrow- .
8.Remove primary chain tensioner (near oil filter) (hexagon a/f 32).
9.Remove cable plug of the coolant temperature sensor -1- . Then unscrew eight M6 x 20 and two M6 x 80 hexagon-head bolts -see figure- .
10.Carefully remove oil pump.
11.Remove old metal seals. The old seal must be separated at the connecting webs -Arrows- between coolant pump and oil pump housing.

Installing oil pump

Information

•The O-rings on the oil pump flange and the metal seals must be replaced!
1.Clean and degrease sealing surfaces on oil pump housing -see figure- and on crankcase (e.g. with acetone or solvent naphtha). Replace both O-rings on oil pump drive flange -Arrow- . Grease oil pump flange and the bore on the crankcase with Optimoly MP 3 special grease (available from Porsche parts service).

medent

So should we now loosen the chain tensioner to help ease the pressure needed to center the shaft? Or should the tension be left as is?
Any chance that the chain might have skipped on the gear? How do we test for this?

KrazyK

Did you lock anything before you began? Its certainly risky to remove tensioners with nothing locked.

medent

No.
And it was the mechanic doing the actual work. I was just standing near him watching the work when this happened. I just re-read my first line and it appears that I was doing the work. He's worked on my Porsches (and many others in the area for years and never had an issue till now).

KrazyK

Wow, if he cant follow a service manual that's bad. If its a legit shop I would maybe step away and let him deal with it. In other words he f@#$% up on not locking engine first.

If you like and think it may help, I can PM you a link to the service manual so you can read/print it. Please don't post the link!

DBJoe996

OMG! OMG! This has all the all the elements and drama of a disaster! Be very careful....

KrazyK

Hopefully you can see everything in this .pdf;





I don't think so. We have reached the quota for disaster threads for the week.


And, Im really sorry. Just realized you have a 2000. The .pdf is for 2002+. Standyby for the 2000 version.

medent

Is the link above for the 2002+ version or is it for my 2000 version?

Byprodriver

He should refer to simple solution offered in post #2.

If you brought your car in for a waterpump replacement you should not have to pay for R&R the coolant manifold as this is not needed. All you have to do is cut the waterpump gasket off & cut as needed for the new gasket as it comes connected to the coolant manifold gasket.

Pressing the oil housing sleeve into the case requires a good amount of force, make sure it is perfectly aligned with the case & IMS before hammering into place with rubber mallet.

KrazyK

If your right then the mechanic is even more clueless. I thought he was having the oil pump serviced/repaired not the WP.

Byprodriver

Probably a old air-cooled specialist