New mode of failure for oil system - car out of commission

I mentioned that I've been seeing a drop or two of oil on the garage floor. Today I found out why. Confession: It's not a "mode of failure" - that was just some RL anxiety syndrome fun. I backed onto my ramps. Since the leak is coming from the drain plug area, my assumption was that the crush ring was seeping, but I chose to loosen the plug a bit and retorque it rather than just cranking down on it. So, I gave the Allen wrench a turn to the lefty-loosed and... Looks like the powdered metal of the magnetic drain plug developed one or more stress fractures and ultimately the head of the plug separated from the body. The GOOD news is that the barrel of the bolt is still in the oil pan, and I'll be able to just remove it and replace it with a new drain plug. *edit* Here's another "after" image, showing the pieces both together as well as next to each other: Unfortunately, the wife won't be back until noon, so getting over to AutoZone is going to have to wait. For now, the car's still on the ramps, and the drain pan is in place to catch any drops.

Bummer, at least this is a quick, easy and cheap fix. May I ask what brand the magnetic drain plug was?

Exact same thing happened to my LN magnetic plug. I now keep a few spares on hand.

same here. Its happened twice now to 2 different LN mag plugs for me. First one I can't fault LN because Pelican, in their instructions, said the torque setting was 37 ft-lb when in fact its 19. But second plug I torqued only to 19 and the same thing happened.

Here are a few alternative Magnetic Drain Plugs http://www.powerslutracing.com/i-200...llen-head.html http://www.powerslutracing.com/i-200...ge-magnet.html http://www.powerslutracing.com/i-200...18-x-1-50.htm\ Amazon.com: Magnetic Drain Plug 18mm x 1.50" Regular Point Zinc Plate 19mm Hex: Automotive Amazon.com: Magnetic Drain Plug 18mm x 1.50" Regular Point Zinc Plate 19mm Hex: Automotive All less then 1/2 the price of an LN plugl My only concern is those plugs are steel and the oil pan is aluminum Here is aluminum one Amazon.com: Mishimoto MMODP-1815B Black M18 x 1.5 Magnetic Oil Drain Plug: Automotive Amazon.com: Mishimoto MMODP-1815B Black M18 x 1.5 Magnetic Oil Drain Plug: Automotive

I can't definitively say I know who made the one that failed for me - I thought I ordered online, but can't find the confirmation email.

And don't bother with the ECS magnetic plug either. After 3 oil changes the soft aluminum was shot and the hex hole rounded. The hole wasn't deep enough to get a good set with the wrench. My tech had to notch it with a dremel and back it out with a screwdriver and mallet

Another case of the "aftermarket diy blues." Of course anything can fail...sometimes...but I haven't run into any threads about the factory drain plugs having this issue. Best thing to do is stop looking for microscopic bits and metal and just enjoy the car.

I Second the Issue with the ECS product. Too soft, needs to be replaced every second oil change.

The Pep Boys generic metric plug is OK for keeping my DT40 in the car rather than on the floor. Tomorrow I'll walk across the street to the Porsche indie and see if he's got one lying around...he's been cool a couple of times about just tossing me a used version of something he could have just as easily charged me for. When my coolant cap on my Boxster blew and I hit him up for a new one, he didn't have one - but he loaned me one from his use parts bin until I could get Pelican to send me the updated part.

I broke a standard plug on my bmw e46 ...always had torques it carefully to correct spec but snapped head off one time when trying to get it off for oil change. I guess these plugs do not last an infinite number of heat cycles. Now I have a spare one and plan to change every other oil change. I'm more hesitant to do that with the 996 .. Since I splashed out for ln magnetic plug - but maybe those should also be chnaged out every other oil change ? I drilled the old one of of my BMW quite easily - but still pain in the rear ..

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I don't do UOA, I don't have a seance or voodoo ritual with every oil change. I don't run my used oil through cheesecloth. I do my own maintenance for two reasons: I hate wasting money, and I like to be familiar with my car's "normal." I love to drive my car hard. It's SO much more fun when the RPMs are high. I understand that component failures occur more frequently in systems that are operated at higher load levels. I monitor the stuff I can (visually as well as via Durametric), and as long as things continue to be "normal," I'm going to continue to beat on the car and grinning like an idiot.

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The factory drain plugs do indeed have this issue, and often have to be replaced every other oil change. I always keep spare drain plugs in my tool box. When we developed our drain plug, we tested it side by side with an OE plug. We wanted to maintain the factory tightening torque of 37 ft/lbs. We also wanted our plug to be at least as strong as the factory drain plug. We achieved that, and strength tests showed that it fatigued later than the OE plug, but still, no aluminum drain plug is going to last forever when torqued and re-torqued to 37 ft/lbs.

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You have a point. Maybe putting in a new crush washer would help. Well, and with a crush washer does it really need to be that tight?

What happened to thumb tight for drain plugs? That's what I did for my E36 M3s and E34 M5 and never had an issue with leaks or plugs breaking. Or am I just showing my age a bit?

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With washers like that I just get them snug and then it's a matter of feeling them crush, once that happens it's good to go. Not sure how many lbs that is, other than pretty sure it was way less than 37. I sleep well at night.

Only tight enough to crush the crush washer. This is a good demonstration of how applying torque is a very inexact science. What we are trying to achieve is a certain amount of clamping force, but the only way to practically measure it is torque applied. Depending on how much oil is on the plug, and the condition and temperature of the threads, 37 ft-lbs applied can translate into a wide range of clamping forces and stresses on a fastener (or plug in this case). A given torque spec may be safe to apply dry, but actually cause too much stress and yield the fastener when well-lubricated.

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It is not a crush washer but a sealing ring and should be replaced and not reused.

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I have to wonder about the skill of the person doing the change. I changed my Boxster's oil a number of times and the same oil drain plug was just fine. What killed it was in a pinch I had the oil changed at a quick lube place and the next oil change -- this time at the dealer the tech found the drain plug wrench hole buggered. What happened was the oil change guy didn't insert the tool bit all the way in. When I did the oil changes one of the things I noticed was how good a fit the tool bit was in the drain plug bit hole. It took a bit of extra attention/effort to make sure the tool bit was fully inserted. With the tool bit fully inserted the force of the loosening or tightening is spread over the entire length of the tool bit hole in the drain plug. The quick lube guy just put the tool bit in until it met with a bit of resistance and that was that. Fortunately the tech managed to get the thing out and had a spare for me to use. I ordered extras and when they came in I gave him one to replace the spare he used and I keep at least one new on the car's center console bin for just in case.

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The one on my plug is metal, and it crushes... A quick heat up with a lighter makes them soft again if a person really wanted.

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No, I don't believe it does need to be that tight to seal, but we wanted to ensure that the drain plug would stand up to factory specs. Correct, not inserting the socket fully into the hex head can wear the plug out in one use, and is probably the most common cause of cracked drain plugs.

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This doesn't sound good as I also have a ECS piece but I've only done 1 oil change on it so far. Just wondering why you kept the hex design which I personally think is dumb when dealing with any amount of torque close to 37 ft/lbs personally. A better design imo would've been to just create a slightly thicker hex nut outer diameter shape instead to better distribute the load and since the center will be solid, maybe engrave a torque value on it to remind installers. I found that using generic or cheap hex tools is a recipe for easily rounding a hex nut on any car as the tolerances and design could be on the "loose" side or designed in a way where the edges of the hex is rounded and thus not creating a good grip all the way in the hex hole.

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Unless Porsche changed the ring/washer that is not the right item. The ones I used in my Boxster and Turbo are very hard, purposely so and is very finely finished. The ring is intended to seal by its finish and flatness not by crushing. Examining a used one finds a very slight depression where the drain plug tightens down on the washer. But it is by no means intended to be crushed like some oil drain plug washers made out of copper or some kind of soft aluminum.

The fact that the plug started leaking about a week ago - a soild two months after my last oil change - suggests to me that the plug is susceptible to cracking when a tensile load is applied and held. The tensile load, plus the cyclic heating/cooling, appears to be sufficient to cause cracking and eventual failure. The leaking oil indicates that the failure was already in progress - attempting to loosen the plug finished the job. I don't have enough knowledge of the part to know if this is a design weakness, an issue with a single part having an inclusion or other flaw that made it more likely to fail, or user error. I'm fairly fastidious when it comes to maintaining the motor, and I do not belong to the "tighten it until your arm aches" school of thought. Even back in my foolish youth when I DID tend to overtighten stuff, I never saw a failure like this. Re: finger-tight drain plugs: Never heard of this. Hand-tight for oil filters I'm familiar with, but not with drain plugs...

...and the owner at Performance hooked me up with an aluminum plug for $5 so I can get the 996 back on the road rather than wait around for a new magnetic plug.

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The one in mine looked like it was a crush washer and snugged up like a crush washer and pelican calls it a metal gasket which usually means its a crush washer. If it didn't crush when snug then they wouldn't call for its replacement since if it was "very hard" and "very smooth" it wouldn't ever need to be replaced.

If I'm not mistaken, the oil pan and the entire engine case for that matter is aluminum. Needless to mention, the drain plug has to be a softer aluminum in order to be more giving during over-torquing. This way you're replacing the plug vs the pan. So of-course it will need to be replaced priodically regardless of who makes it.

Are you guys using the right washer? The stock washer is soft aluminum that will deform a bit when tightened down to achieve the sealing http://www.ecstuning.com/ES1376018/ I think the magnetic drain plug is an engineering challenge as I can't imagine the magnet can contract/expand as well as aluminum during all these heat cycles.

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While the sealing ring is hard and finely finished it does deform a bit from use. The drain plug forms a depression into the face it tightens against. The ring gets replaced because one of its smooth surfaces is no longer smooth and is at risk of leaking. Additionally the now deformed and damaged surface is at risk of compromising the sealing surface of the drain plug which is bad enough but at least the drain plug can be replaced. But if the damaged surface of the ring is against the drain pan's sealing surface this can damage this sealing surface and the drain pan can leak. That is a more expensive item to replace. (The techs tell me they can always tell when the sealing ring has been reused as there is some oil weep sign at the drain plug.) The ring wants to be replaced every time so both surfaces of the ring are virgin and these virgin surfaces effect an oil tight seal at the drain plug and the oil sump. This works to keep both the drain plug sealing surface and the sump sealing in pristine condition so with a new ring they continue to form an oil tight seal and ensure the drain plug when tightened down is not tipped slightly if it gets on the slight ridge that is formed from the prior use. The drain plug tipped or cocked slightly means the drain plug may not remain tight.

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Lol

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x2. Never heard of that theory before.

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Funny how you think that is funny. I think the practice of re-using the sealing ring is sad. And the use of some soft deformable washer or "gasket" sadder still. I'm amazed at how callously some owners tend to their vehicles. And it just further puts me off the owner serviced vehicles for consideration when shopping for another car.

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When I first read this...it gave me a woodie. Seriously though, it beats the hell out of all that talk about "fingering your sump". Seriously though...has Macster ever been wrong?

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That is not a theory. I would think it obvious that absent any sealant, o-ring or some other sealer that the ring and its two surfaces is expected to create an oil tight seal between the drain plug and the sump. Additionally the ring must be firm enough to resist compression and further deformation from the heating/cooling cycles to avoid the drain plug from loosening over time. The called for replacement of the ring is to avoid the deformation the ring gets from the drain plug being tightened from possibly damaging either the drain plug or sump sealing surfaces. The ring in this case is the sacrificial item with the idea to prolong the life of the two more expensive items: the drain plug and the sump plate.

I honestly cannot believe this discussion exists. Macster is obviously correct. But it is also obviously true that many people don't replace it and few if any engines have exploded as a result.

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Only Macster can turn "Just use a new crush ring" into a thousand-word essay involving weeping virgins. I don't think "callous" and "had to reuse a crush ring because I didn't have one handy" are necessarily equivalent. If you're operating under the assumption that every service tech out there is more fastidious than every owner who does his own service, you're fooling yourself. Techs don't get paid a ton, and they're often getting harped on to churn through the cars. I have quit using some dealership service departments because of issues ranging from simple mistakes to outright lying on paperwork to skip doing the steps on the "XX point inspections" they love to advertise. I do not take any of my cars in for brake work - I won't have my wife driving around in a car where the safety equipment was serviced by some guy who doesn't get paid much much, is likely nursing a hangover, and doesn't really give a damn about anything beyond getting the wheels back on and moving on to the next ticket. Sure, there are inept owners out there - but there are also sh*tty techs out there. If I buy a car from a DIY owner, I can get a feel for how capable and knowledgeable that person seems. I get no such impression from a stack of dealer/indie records.

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To be honest, I don't know what you said since I usually stop reading after a couple sentences since your posts are usually long with every possibility thrown in hoping one of them sticks. I do know that "crush" washers have been used several years in several cars. I call them and will often refer to the crushing abilities to maintain seal. As such, they should all be soft aluminum as stated. Do I replace them every single time? No. Do I get a leak if I don't replace them everytime? No. Do I use a torque wrench? Only when I'm working on vital parts of the engines like Cylinder heads/blocks. I don't really see making this trivial than it has to be but that is the good ol fashion RL way. Bottom line: Since the oil pan on the 996 is aluminum, better attention needs to be paid in tightening the oil bolt. One should not overtighten it to compensate for the lack of seal on using either a substandard washer or a used washer that can't compress any more without going over the torque limit that the pan/bolt was meant to handle.

I sent photos of the drain plug off to a forensic engineer buddy because I thought he'd find it interesting. He did. "Verrry Interestingggg! It looks to me like a low cycle fatigue failure. Note the angled fracture surface. A 45 degree angel would be the shear plane for the plug." I'll stick to new aluminum plugs at every change a filtermag from now on. I have no interest in wondering whether the damn oil plug will crap out...

Jeez Louise The washer is all of .97 cents! Next time you place an order with __________(insert parts company), order a few and you will always have one available You spend $60-$140 for a DSY oil change, you can't spare a buck???

I replace my oil filter like every two or three oil changes because it costs like $8. Now your telling me I should replace the plug washer every time too? My wife is going to kill me when she finds out how expensive my oil changes are going to be now. She is going to make me sell the car...oh my oh my! I have nothing else to add..........

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Lots of cars (probably most) come from the factory with aluminum pans/sumps and steel drain plugs (including old 911s).

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While there are many excellent techs out there I've found that there are an equal number of mechanics (dealer and indy) who cut corners, break things, leave fasteners loose as well as lie to the owner of the car about its condition. I've also seen a few mashed crush washers that have been clearly used many, many times.

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No contest to your comment but I was talking about the 996 specifically. Agreed, but if you think there are equal number of honest and dishonest mechanics and techs than you are a "glass is half full" kind of guy. Not me. I tend to think that only 20% are truly respectable.

This thread was intended to provide info on the magnetic oil drain plug breaking into two pieces. If you have any questions about that subject, please feel free to PM me and I'll provide whatever info I can. After reviewing my records, I believe that my 996 was equipped with the magnetic drain plug when I purchased it, so I am unable to determine which manufacturer's plug it is. Since this thread has devolved into a pissing contest about crush rings, I deem it too stupid to continue living. I'm pulling a JI and locking this bish. Siujn8r.gif

Uncorked by popular demand. Let the tarding begin...er, resume... I believe it is OK to reuse your crush ring if you have it resurfaced. This is probably the most economical way to proceed.

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Resurfacing would depend on how much metal you have left to work with.

I could probably have some additional material brazed onto the ring and then machine it down to the original tolerances.

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You'd be a fool not to.

We need input from KK on this issue. What is his crush ring per mile driven ratio? 1/10 or less? Did he notice any performance loss if he failed to proactively replace the ring with a new one in a timely manner? Did he polish it to mirror finish every time he detailed his engine?

Look guys, you can buy a brand new sump plate on Partsgeek for $169 delivered. I'll bet Jason at Warehouse33 can get them for half that. Don't jack around with the drain plug - just do it the Rennlist way and replace the sump plate when you change oil. This way the oil drains out much more quickly and you ensure that you haven't left in there any old oil, sludge or worst yet, metal shavings. It's a best practices thing. By the time you replace or resurface your crush washer every oil change and your stripped out drain plug every couple of oil changes, you may even be money ahead by swapping the sump plate. Plus, the sheen of a virgin sump plate after an oil soaked fingering of the edge crevices (to ensure a tight seal) is much more aesthetically pleasing when you are admiring your 996's business end than the beaten, abused and scarred up sump plate that was broken in by the original owner lo those 16 or so years ago.

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Nearly spit out my nightly vodka nightcap on that one.

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Our drain plugs are billet and made from 6061-T6511, so no powered metal or castings here! :-) We have had very few complaints about drain plug failures, maybe a half dozen a year (with most having been in service for years), and considering we have sold over 50,000 plugs (if not more), that's a very small failure rate. When they do fail, the engines don't leak oil or if they do, it's a minuscule amount and does not result in some sort of catastrophic failure. In most every case, we will replace the drain plug free of charge if it hasn't been over-torqued or shows sign of abuse. It takes a simple phone call or email to get it sorted out, but more often than not, we aren't notified and we see it on the forums first. As of earlier this year, we switched the anodizers we using as we were having issues which could have led to some of these problems with the plugs. To my knowledge, since the switch over, we haven't had any issues or complains about broken plugs or tight threads (from over anodizing). From the photo, that is a very old plug - they have been revised several times since the DFI engines came out in 2009 to allow for compatibility with both the M96/M97 and 9A1 (MA1) engines. If the drain plug has been in service for many years, then it's time to just replace it. They don't last forever and the magnet does get weaker over time with the contstant high temps it sees. This is no different from the factory plastic filter housing bypass springs that get weak and then the filters run in bypass all the time. Some shops change out the housings every few oil changes, and with good reason, or just put a spin on filter adpater on it and be done with it. That said, call us up and we'll take care of replacing that drain plug or if anyone else has any issues/concerns, just email [email removed] or call and my team will get it sorted out.

^^^^ Great service/honesty/transparency right there.

I'll add that this component one one of our earliest developments. I did all the testing and installed the first one ever put into service. Every engine we touch gets one, and we have certainly installed at least 1,000 of them over the years. Of those, I have had one failure. That was after a Jiffy lube did an oil service, so no one knows what they did, or why. I was surprised that they actually drained the oil, and didn't extract it with a pump through the oil filler. That one had been in service since 2008 and it failed in 2013.

This is how my LN failure looked.

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^^^ That looks cast to me. When did you buy it? Any version or number on it?

Not sure. It came on the car when I bought it. I may have already thrown it away but I have the receipt in the car file somewhere.

Not cast, that's our plug, and probably first gen at that. We were able to duplicate that failure, but only when threaded into a steel plate and torqued to over double the torque spec. We changed the hex back to the smaller stock size years ago as well as changed the depth of the hex to increase the cross section thickness of the plug to make the plug more resilient to repeated over-torquing.

Thanks for the comments, Charles. I didn't buy the plug, so I have no expectation that you'd replace it at no charge, but the additional info is appreciated.

The only way sump mating surface can get damaged by a reused crush washer/gasket is if it gets put back backwards from the original installation. If you pay attention when reusing it and inspect the poor thing to make sure it�s not too stretched out then you will be fine. Use common sense people. Porsche techs tell Macster anything just to make him go and as usual, his long winded replies are only partially correct. Just enough to make those that know less than him believe everything that he posts and this is dangerous.

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5CHN3LL, you better lock this bitch. The thread has served its purpose.

In before the re-lock!!!!!

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The techs didn't tell me what I posted. If one understands the interaction and the proper function of the sealing ring -- which is how it is named by Porsche -- the ramifications of reusing the ring or replacing it with something else are obvious. The reuse or replacement by some other soft/crush ring/water of this vital sealing ring by some owners is just more evidence many who self-service their cars shouldn't.

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[Image-only post; no author-written text. Original image references:] https://rennlist.com/forums/graemlins/thumbup.gif

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I don't think it's sad, if they work they work and it's not too hard to inspect them before putting them on - and - it's not hard to make them soft again if they don't seal up. Although, I guess, for the pain in the butt some of these are to replace it wouldn't be worth it to reuse them a lot, but it's not like after 2-3 or so uses they would be bad. This isn't rocket science.

Since this is about to circle back to crush rings (*sigh*), it is getting locked. Feel free to head over to the GW thread and carp about it if necessary.