Not a good idea to put a jack under the oil pan
 

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.

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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............................

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.

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.

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.

:cheers:

Funny thing….
 

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

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

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

https://shop.harborfreight.com/media...mage_11976.jpg

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...

No.........

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.

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

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.

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:

https://m.media-amazon.com/images/I/...AC_SL1000_.jpg

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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.

Thanks for the info. True, very good point.......I need to search up my llifting eye.

As I recall that thing is very thin with an M8 going into the case

But is there for the purpose; to date, I have never heard of anyone having a problem with it.

JFP, this is my 'beaner' engine support bar sourced at Home Depot :p

PS: you adjust the height by turning the nut on the hook

http://986forum.com/forums/uploads02...1631308001.jpg

It gets the job done.

So…..
 

…..People will invest multiple thousands of dollars on a Porsche, but they won’t take five minutes to read the owner’s manual that the Porsche engineers who built the car, put in the car.

But they WILL spend an hour on their computer to read advice from idiots on the internet.

We are doomed.

deleted

78F350, thank you you providing a source.

This part of the manual refers to lifting the vehicle. Can we infer?

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In the past I have used a long engine hoist, a supported 2x4 with a chain, and raised/lowered the engine and transmission on a padded board with an ATV jack. My $99 1,100 lb engine support bar is now due to arrive on Tuesday.

Ahhh yes, it's been a bit since we've had an "all hail stuttgart" string going.

JFP, you do this for a living. I fully expect that your engine removal procedure involves mounting the support bar, raising the car on a lift, and dropping the engine low enough to mount the m96 standoff and attaching it directly to an engine stand. There is zero risk there and the last thing you as a professional would ever do is take a risk with a customers (or your own) car.

If you don't have access to these tools though, that doesn't mean you can not safely do the job.

I'll say again that doing something dumb (like jacking the car by the oil pan) will end poorly.

But analyzing a situation and proceeding differently than what the original engineers had done does not make someone an idiot, and owning/working on a Porsche does not require large sums of money to be done right (10, haven't we already had this discussion before?)

For the record - I have manipulated an m96 with a jack using an appropriate sized piece of plywood for several projects (engine mount, tranny mounts, air box removal, injector swap) without harm to the pan. Also, the motor can sit flush on concrete to work on it without collapsing the pan.

Don't knock people for making due with what they have. Necessity is the mother of creation.

God forbid a porsche engineer ever find themselves needing to take a **************** in the woods without toilet paper. Whatever would they do...

Btw - I have trained under and worked with some true mental giants, but I will tell you that some of the most intelligent people I have ever interacted with are farmers who never graduated high school. So, if you think that this way of thinking makes me an "unreliable" source of information, I would challenge you to rethink that position. Everyone has something they can teach, and everyone has something they can learn.

Sorry, that last point is a purely philosophical one but to me is very important.


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As the original poster I feel the need to add a few comments.

1) I am surprised at the response… guess it was a worthwhile thread to post.

2) A couple of people suggested that one should read the Owner’s Manual…
I wasted some time looking at the owners manual that I have and, as I expected, found NOTHING on supporting the engine… which is what this thread is about.

3) Since I have my cracked oil pan sitting on a table I have spent some more time inspecting it and make the following observations.

a) The the lowest points of the pan are the two front to back ribs on either side of the circular depression for the oil pickup and also the part of the casting around the drain hole.

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I coloured one of the ribs red so it would stand out in the next photo.

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So even if a plank is between a jack and the pan the weight will be on the ribs and the raised part around the drain hole. My pan does have cracks around the drain hole and at least one of the ribs, even if the worst ones are in the center around the oil pickup depression.
I marked the cracks in black... these are cracks that I can feel with a fingernail.

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So just putting a plank or piece of plywood will not prevent the weight being concentrated in the middle of the thin casting.

My solution for future engine removal will be to make a square wooden frame that fits around periphery of the oil pan, under the bolts, which will accept the weight from the vertical walls of the sump.

For supporting the engine for engine mount removal there are areas of the crankcase in front of and behind the sump that are about an inch thick that should do very well, of course with a piece of wood on the jack.

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I could use my engine support bar but that means going to all the bother of removing the engine cover and I would not be comfortable working under the car with the engine weight on that little bracket... even if I have hung the engine on it in the past (when I wasn't under the car) and even if Porsche recommends it. But that's just me.

b) Most of us, after the removal of the engine, put it on a dolly of some sort… where the same problem will occur. A carpet or rubber layer on the dolly (or lift table) will help distribute the load but it has to be soft and deep enough to allow the central part of the pan to sink in about a quarter of an inch before the load will be distributed to the rest of the surface area of the pan. The wooden frame that I plan on making will overcome this problem also.

c) I have an engine support bar (that I made myself), but using it to lower and raise the engine would be a way too unwieldy with the equipment I have, so I will continue to use my transmission jack with the wooden frame (that has yet to be created).

Totally agree with you, I was raised on a farm and that training allows me to do what I do now... even though sometimes the way I do things may seem (or be) somewhat bizarre. And sometimes I screw up and learn something new!

Haha yes! I never question the madness until I can understand the method which justifies it. Thats how we learn.

I've been to lectures that discuss the definition of an "expert" and my favorite always will be the person who has already learned all the mistakes and knows not to repeat them again.

That's the beauty of professional training, as well as this forum, is to the ability to admit our own and learn from each other's successes as well as mistakes.

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