What part is this oil leak coming from called?

Eat-um-up · Eat-um-up's Garage

Apologies for the duplicate. I posted this in the 911 technical forum when it really should have been here.

I recently acquired my 2005 997.1. There is a small very slow oil drip coming from the drivers side around this big nut with a hollow centre.

I found an underside picture online and added an arrow to it for reference.

Can someone tell me what this bolt is for? I suspect it might be an oil tank drain but Im not familiar with these engines yet.

yelcab1 · 12-11-2019, 02:30 PM

Oil chain tensioner.

Eat-um-up · Eat-um-up's Garage

Quote:

Originally Posted by yelcab1

Oil chain tensioner.

thank you.

Is that a part I can pull, replace the o ring and reinstall to torque? or does it have some kind of calibration that would have to be made / non reasonable etc.?

yelcab1 · 12-11-2019, 02:56 PM

That is a part that you can remove then replace the seal and the aluminum gasket. However, you need to drain the oil from the engine or there will be a big mess. More importantly, 9 times out of 10, the now-loose cam chain will not move out of position while you are doing this work, but that one time out of ten, it will move and you will be in trouble. To totally prevent that, you need a cam locking tool. You also need a big wrench and a big torque wrench.

Frankly, if you had to ask what it is, this is probably not a place to start learning. But, it is your car and you know yourself best. Dive right in if you think you can handle it.

Eat-um-up · Eat-um-up's Garage

Yelcab1,
Thanks for the tips. I've read that oil dripping from the rear drivers side could indicate the IMS starting to fail. I've rebuilt a few engines but my experience is rusty. My thought was that given that its not in the area of the flywheel that it was likely something else. But i wanted to be sure. My experience is with the 70's area of air cooled motors and modern chevy's.

Still sound advice.

I still need to get a service manual for the car. I just haven't gotten around to it. It sounds like repairing the oil leak wont be too bad to do. its something ill plan to do with my next oil change. It barely leaks (like a couple of drops after a day out sitting over night) So it should be fine until then.

Thank you for your assistance.

yelcab1 · 12-11-2019, 03:25 PM

There are other more reliable indicators of IMS impending failure. You should do some research on that. If I had a 996, I would replace the IMS bearing as a matter of preventive maintenance and not wait for it to fail.

My apologies. Your engine rebuilding experience will serve you well with this engine. Good luck, it's just a bucket of nuts and bolts in the end.

Eat-um-up · Eat-um-up's Garage

no apologies necessary. You have no idea of my skill level or who else might be looking to do this same thing. I think your statement is a wise statement.

The IMS is a back of mind fear as I didn't realize the 05's shared the 996 engine when i bought it. So I didn't budget for it when i bought the thing,

yelcab1 · 12-11-2019, 04:45 PM

Oh you have a 2005 997. It does have the IMS issue but not as much as the 996. I would think watching the cam deviation, watching the oil filter residue for indications of bearing material are sufficient until such time that you want to do a clutch job. Then, the beefier IMS bearing can replace the stock bearing.

looneybin · 12-11-2019, 07:22 PM

Not as easy as that
The 997 uses the larger IMS that requires splitting the case to replace
At your next clutch job, Just pop off the seal to let fresh oil in, and you should be OK

yelcab1 · 12-12-2019, 06:17 AM

Quote:

Originally Posted by looneybin

Not as easy as that
The 997 uses the larger IMS that requires splitting the case to replace
At your next clutch job, Just pop off the seal to let fresh oil in, and you should be OK

Even better....