okie981

Resurrecting this old thread because I just experienced what the OP was asking about. I had done several oil & filter changes on my BS and at 23k miles yesterday I decided to install a new oil filter housing with my new filter. I used a genuine Porsche part. The new part required at least double the torque to spin it on as compared to the original housing the car was delivered with. It was impossible to spin it on by hand up to the o-ring contact when I could with the original part. I took it back off and removed the filter just to make sure I was dealing with only the torque to drive the housing on. Then I reinstalled the filter in the housing and drove it on with a wrench. It was possible with a 6" ratchet handle.

The new part has threads that fit a lot tighter in the aluminum threads of the housing mount. Not cross threaded, not dry threads (some residual oil was on the aluminum threads), not the wrong part.

My theory is that Porsche sourced some housings from a different supplier or they are made from a different material or both, and the resulting plastic threads are on the high side or beyond the design tolerance for fit.

NOTE: The engine block had cooled to almost ambient temp after letting the oil drain for about 4 hours and had a 12" fan blowing under the car to help cool things off, but the original housing backed out with typical torque at that temp and I followed within 10 minutes to screw on the new housing albeit with much more torque required.

NoGaBiker

Just read through the thread and I'm amazed nobody states the actual OEM torque spec. It's 19 lbs-ft. Ironically, I did my first oil change on it yesterday. Man, it's hard to keep wailing on that plastic housing with a long handled torque wrench! I was never so glad as when I heard that Click and the housing was still intact!

Filter housing is 19, and as stated above, drain plug is 37.

As I had a 991gts previously, I've change oil on the 3.8 before. I've always had to jam the filter up onto the receiver and make sure it's well-seated before installing the housing over it. Trying to seat filter in housing first never works for me.

Van Larson

FWIW, and for several reasons, I installed both the LN magnetic drainplug and filter adapter so a standard Napa Gold filter can be used. Much less finicky and cleaner to drain.

okie981

Correct, those are OEM torque values for those parts. What I experienced with the housing replacement is a large increase in torque required to drive the housing up to the point where the o-ring made contact whereas before with the original housing I could easily turn it by hand, no wrench required. I don't know how much torque it took but I know it was more than 18 lb-ft.


I had my eye on this spin-on adapter this weekend when I was on LN's website ordering some more oil. When I use my one and last OEM filter I have on hand, I will install this part. The Napa Gold filter is $8 on Amazon.

Van Larson

You will need a 26 mm socket and
Torque wrench for install.
You can borrow mine if needed--took awhile
For
Me
To find one.

okie981

Thank you kind sir but I have a 26mm socket and torque wrench on hand.

4carl

What I would consider if you change to the LN adaptor it may give Porsche an out if any engine issues come up. Not saying it will cause any problems and may actually be a better filter set up but manufactures look for any out with warrenty work. Carl

okie981

I ain't skairt.

fishing

I changed my oil a couple weeks ago and noticed the same increased torque needed to seat the filter.

Van Larson

I cannot disagree if you are under warranty or CPO. Comment only for my feelings and way out of any warranty.

4carl

Same issue really dont know whats going on. its my 4th 981 and 2nd GT4 never had the problem before. i even measured the canisters with a vernier caliper! cant figure it out why its so hard to get seated. tried it with the engine cold and hot, same.
carl

okie981

Ok, so mine isn't a fluke occurrence. I'm sticking with my theory that Porsche changed the material and/or the supplier of the part. There are several thermoplastic materials that will perform well in this application, and they all have different properties when molded as far as how much they shrink or don't shrink from the mold's original shape. And if they changed suppliers, it could be a different set of tooling for the mold so even if the same material is being used it could have a slightly different shape/size to the threads. I think the friction is all in the snug fit of the threads. The friction is much higher before the o-ring contacts the aluminum part of the oil filter mount.

But having said all that, the part should not take more than final tightening torque spec to drive it in to a seated position. Porsche fail on this one, tsk, tsk.

fishing

Changing the oil turned into a PITA as I used a torque wrench and had a filter leak when I started the motor. I inspected the filter and saw it did not appear fully set and flush. Not being sure if I misthread the canister or O ring, I performed another oil change to inspect the part. Thats when I determined it was probably just difficult to thread and I must not have fully seated the filter the first time. The second time I just seated the filter without the torque wrench. This took much more than 19 foot pounds.

sonorous

So Carl is it safe to say that this is the same problem you posted here? https://rennlist.com/forums/gt4/9552...-hard-way.html

In that thread we were both theorizing that it was relating to the O-ring but maybe it is just the threads that are tight?

In any case, the issue is real, so for anyone changing there own oil, my suggestion is to make 100% sure the filter housing is fully seated before thinking you are done. This can be easily accomplished by a visual inspection of the filter position making sure there is no gap.
Don't go by torque alone.

NoGaBiker

I'm not really clear on when this is happening to people. Are you who are experiencing the tight threads doing so exclusively with replacement OEM housings, or is anyone experiencing it with the original OEM housing as delivered with the car?

I just did my second change, at 6600 miles, using original housing and had no issues. Ran it in by hand, tightened with a good, expensive 3/8 torque wrench to 19 pounds, no leaks. The first change was done by the dealership right before I bought it so I don't know for a fact that it's the original housing, but I'd be shocked if they replaced it unless they cracked the original. So I'll assume it's original.

For the record, I've never replaced the housing on any water-cooled Porsche I've owned over the years, and that includes owning one for 45,000 miles, so that was probably 8 changes or so. I've also never experienced this tightening problem that I recall.