Oil change - O ring replacement - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Frodo · 10-23-2008, 01:56 PM

Had an oil change question. I've got the filter off and am replacing the O-ring on the housing. My question is where exactly it goes.

Does it go into the channel right next to the threads, like this:

Or, does it go right up against the flange, ie a little further from the threads (though in this pic part of it is not quite totally up against the flange), like this:

I'm thinking the first choice is right, but I wanted a second opinion.

Thanks in advance.

FrayAdjacent · 10-23-2008, 03:33 PM

First, your camera should have a 'macro' function. That allows it to focus on things REALLY close. The symbol on the corresponding button looks like a flower. (just trying to help)

Second... I THINK it goes in the channel. I changed my oil a couple weeks ago... and the o-ring.. but darn if I can't remember 100%

blue2000s · 10-23-2008, 03:44 PM

It goes in the groove next to the flange. If I squint, it looks like your second picture. If you don't get it in the right place, the car will tell you very quickly by pouring oil all over the ground.

Frodo · 10-23-2008, 04:12 PM

OK, anyone want to chime in as a tie breaker?

Actually, I have changed the oil in the Box once before and I'm pretty sure I put it in the channel (Photo 1), and it didn't leak. The last time it was changed, I had Porsche do it in conjunction with the 30K maintenance (for warranty purposes, I wanted to have them do that one). When I removed the filter housing today, that is where I found the O-ring (ie, in the channel). And I've never had problems with oil loss.

But I got to thinking about it, and it just seemed to make sense that one would put the ring right up against the flange (Photo 2). However, when I'd put it there, it had a tendency to want to roll off back into the channel (as in Photo 1).

So I'm sittin' here with an oil-less vehicle that I'm hoping to take to work tomorrow. I have replaced the drain plug, and the filter, with the O-ring as in Photo 1. And I'm just itchin' to pour fresh oil back in so she's drivable. And Game 2 of the Series is about to start. And I've had no dinner. And I need to go pick up my son from a friend's house. HELP!

blue2000s · 10-23-2008, 07:16 PM

It should be the deeper groove. It's really hard to tell in the pictures but if that's a bit down from the flange, then that's it.

If you've got it on and it's not pouring oil everywhere, you've done it right.

Frodo · 10-24-2008, 05:18 AM

I put it in the channel, as in Photo 1 (ie not directly against the flange). It just seemed to me that an O-ring (that, if cut, would be circular on cross section) should fit into a channel and not up against a flange. (It's not a flat gasket after all.)

Anyway, fired it up and no leaks seen so far.

On a related matter: How many people actually use a torque wrench to achieve "25 Nm/19 ft-lbs" on the filter housing? As long as you don't strip threads, is it possible to over tighten it??

BTW, Fray, you're right: lousy pics. (Had I been running around with my camera specifically seeking out stuff to shoot, I'da thought of hittin' the Macro. For some reason yesterday I didn't.)

Lil bastard · 10-24-2008, 06:42 AM

Quote:

Originally Posted by Frodo

...On a related matter: How many people actually use a torque wrench to achieve "25 Nm/19 ft-lbs" on the filter housing? As long as you don't strip threads, is it possible to over tighten it??...

Yes it's possible to over-tighten it, though not likely if hand turning it! Being plastic, it can warp and come away from the mating surface in spots, or the 'o' ring can get crushed, both allowing leaks. Also, you could easily strip the threads in the housing again because they're plastic.

But, just as w/ a spin-on oil filter, you should 'lube' the 'o' ring and then hand-tighten it, this is the best - not going to get near 19 lb.ft. with just your hand.

jmatta · 10-24-2008, 07:32 AM

Having just changed the oil the other day on my Box, the O-ring goes in the deep channel, as I think your first photo indicates. Sounds like you already have the car together, so you likely figured it out.

Frodo · 10-24-2008, 02:07 PM

Yep, lubed the O-ring (Sounds kinda perverted, don't it?

), then hand-tightened as far as I could, then wrenched it maybe 1/8 turn (maybe less). Felt nothing strip, heard no plastic cracking and seems to be holding oil.

It's a little tougher with the Boxster than in my other car (a Toyota), which one tightens til you feel the rubber ring touch the base, then tighten it another 3/4 of a turn. With the Boxster, I couldn't feel it suddenly giving more resistance as I got close to the end point---it just seemed to gradually give more and more resistance as I turned.

For anyone trying this for the first time with your Boxster, believe it when people say the oil really comes out fast. I've got a catch pan that's basically a self-enclosed container (I'm guessin' it holds maybe 15 quarts) and is fairly flat on the top, the surface angling gently down to the hole in the center. When the warm oil came gushing out, it hit that almost-flat surface and made a small wave that shot over the side of the collector. So even though I didn't have the disaster I had the first time I changed the oil, I still ended up spilling a bit onto the driveway (maybe 1/2 cup).

I've got an old metal funnel that I think I'm going to insert into the hole next time. I'm thinkin' that'll do the trick.

Thanks everyone for the input.

jmatta · 10-27-2008, 06:32 AM

That's nothing compared to changing the oil on a 911 with a dry sump system. Most the oil resides in the tank and when you open that up, watch out. I have one of the 15 quart catch containers and always put something underneath because the drain hole can hardly keep up with the amount flowing from the tank.