Not a good idea to put a jack under the oil pan - 986 Forum - The Community for Porsche Boxster & Cayman Owners

It has been suggested by some that it is OK to support the engine with a jack under the oil pan for jobs like changing the engine mount. Personally I have never felt comfortable with this although I may have done it... using a big plank between the jack and the oil pan. While cleaning my oil pan today I found multiple cracks around the drain hole and around the indentation for the oil intake. There is no evidence that the pan hit something although perhaps it somehow took a glancing blow. This engine always seemed to have a bit of oil seepage on the oil pan, although not enough to drip.

The sump cover is cast aluminum, the only thing weaker would be cardboard. I have never understood why people insist on trying to jack these cars up using anything other than the intended jacking points built into the car for the purpose............................

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Whoever suggested that must not like you. Any google search on jacking up a Boxster from underneath the car will provide guidance and none will tell you to use the oil pan as a support.

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It was not me who did this, the cracks where evidently there when I bought the car three years ago. I hope no one is foolish enough to jack up the car using the engine sump... but some people suggest supporting the engine with a jack under the sump. From the Pelican Parts site technical articles: "Replacement of the mounts couldn't be easier... Gently place the floor jack under the engine sump, taking care to only apply enough pressure to relieve tension on the front mount... " Note that this article does not even suggest using a block of wood between the jack and the sump.

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My recollection entirely isn't clear... but when I replaced my water pump and motor nount I may have blocked the pan jacking up the engine an inch or two to clear a bolt. No harm done. I wouldn't do it as a matter of routine practice.

…..Porsche included an Owner’s Manual with every car.

.....but that assumes people READ!....... usually a wrong assumption!...LOL

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Just another example of questionable information posted by them. You should NEVER use the sump to support the engine, even for a few seconds. There are tools to do this properly without damaging anything: Engine support bar

There is of course a central structurally sound unapproved jacking location in the middle........but if you get the wrong spot you will potentially damage other stuff. My car is so low in ride height that I usually jack from the lower control arm hinge near the upright and then get one stand at a time under the rear jacking points. Then go for the central location if needed, to go higher. I believe I have used the pan toward the edge to support the engine only but I have a Mantis deep sump which is a fairly thick billet aluminum component. If one plans to change transmission mounts is there a recommended support location on the engine / trans.? ...without the use of the support bar?

I think the criticism here is a bit pedantic. The size of the oil pan is what, 8"x14"? The motor weight ~450lbs in total. If you support the entire oil pan with a rigid material - thick plywood, for example, that comes out to about 4 lbs/insq. I despise cast aluminum, but even it can tolerate that. Don't misunderstand me, I would never put a jack directly on the oil pan for ANY reason. But a lot of people, myself included, have replaced engine mounts or dropped the motor completely without this issue. JFP, as usual, is correct in pointing out the Porsche recommended technique for manipulation of the engine (the cars were actually braced for transport using that device - I wonder what happened to all those?) But I don't think its fair to say that you have to use one of these if you manipulate the engine for any reason, even for a second. Take it with a grain of salt though, everything I do is farm-engineered to some degree...

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No.........

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That's fine, because it is your money and your car, and only you need to deal with the outcome; but for someone that some people consider a "reliable" informational source to recommend a questionable procedure to those somewhat uninitiated as to what can be the unexpected result is simply not acceptable. Engine support bars are not overly expensive, even Horror Freight sells one. They work on just about any vehicle and get everything out of the way when working safely beneath the car. They are a useful and inexpensive addition to any shop's equipment.

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Come on Jeff, you have been on this forum for a long time......

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True, but I still see what is a bad idea as just that. We had a customer follow the so-called "advice" source quoted above, only they used a bottle jack without anything to distribute the load ("Hey, no one told me not to do that!"). You can just imagine what that sump cover looked like when the car was flat bedded into the shop. They were all kinds of pissed off both at the source, and us because we refused to "Just weld up the hole.", or slather JB weld over it. We only fix stuff the correct way, no short cuts, or cheap outs. And after a while, you get tired of fixing things that should have never been damaged in the first place.

Re trans mount change: Okay, perhaps one loose trans mount at a time, with a couple 2x4s side by side (for load distribution) in between the jack and trans case (at the mount pick up section; same loaded section) is a reasonable "at your own judgement and risk" proposition JFP I completely understand what you can recommend and what you need to stay away from.....

Re trans mount change: Okay, perhaps one loose trans mount at a time, with a couple 2x4s side by side (for load distribution) in between the jack and trans case (at the mount pick up section; same loaded section) is a reasonable "at your own judgement and risk" proposition JFP I completely understand what you can recommend and what you need to stay away from..... I may just get a support bar for near term airbox work/tinkering......which I know you are a fan of . Do you have a good Boxster specific one you use or think highly of?

Well I'm pretty upset this bad info is out there, I did a lot of research before replacing my motor mount and this is the first time I am hearing using a jack from the bottom to support the engine is a bad idea. I wouldn't have done it that way if I had known it could crack the oil pan. I'll be adding this as an inspection item when I change my oil. That said, I have not noticed an issues with my car since replacing the motor mount. I used a 2x4 to spread the weight out. If it starts leaking I guess that's my excuse to replace the oil pan with a baffled X51 kit.

Rick, Even though I think I know what am doing...these days I try to read up on procedures from 3 different sources if possible.....and there are still blind spots.

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Engine support bars are a "universal" tool, designed to work on as many engine bay types as reasonably possible. Two caveats are to make sure the bar adjusts wide enough to span the bay and pay attention to their load capacity. I have used the OTC Stinger bar for years, which can lift and hold up to 1100 pounds, and it works fine on these cars; but there are other good ones that are comparable to the Stinger at lower costs, and there are even three-point versions with even higher load capacities, sold by everyone from Horror Freight to Amazon:

Besides the obvious safety these things add, when you are working underneath the car, say doing an IMS retrofit, there is absolutely nothing in the way once the trans is out, and you can lower or even move the car around inside the shop without having to worry about it.