Engine mount replace and not jacking car up?

This will be my first DIY on my new to me 100k 1999. Engine mounts need replacing. I have the mounts, a brand new set (4) of Esco jack stands, and a low profile jack. I've never jacked a car onto stands before. The placement of the car in garage is so I can only access the rear right now without some major reshuffling of the garage. So can I: A) only jack the rear up one side at time to place stands? B) do work on floor and support engine with block and jack? I know B is possible, but it seems the videos and posts i've seen where this is done, the engine as shifted on one side or other. Not sure if related to car being on wheels. Does the front have enough clearance to angle up from rear? Is there safety concern of no brake or engine to hold front wheels? Thanks. Gotta start somewhere eh?

Go with option B/, its a simple job. Don't forget to apply penetrating oil, or similar, to top and bottom fasteners a day before

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Ditto. PB Blaster and wear eye protection. You�re literally only moving the engine mm�s vertically to take weight off mounts. A �gotcha� I found on my car was someone had tried to brute force one side and the square sheetmetal hole was deformed. I had to do some file and Dremel work to fix so the mount would seat properly.

Definitely support the engine from below with a jack and wood. I was able to do this without jacking up the car. Since it's your first DIY, you don't want to cut corners

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Ok thanks. Will spray the bolts prior. Do I need to jack the engine up higher than what it's at now because it has dropped so much? (yes will jack with wood between jack and engine)

No need to lift the engine with the jack, just support it. 1) Put a board between the jack and the sump plate. 2) Raise the jack until it meets the sump.(do not raise the engine or vehicle) 3) Remove airbox 4) Remove the engine mounts 5) Take obligatory picture comparing old vs new engine mounts 6) Install new engine mounts (This process will likely raise the engine so it is no longer resting on the jack) 7) Remove Jack 8) Reinstall airbox 9) Go drive it! 10) Post results and comparison photo on Rennlist

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I never raise the engine, but I have pneumatic tools that can break any frozen bolts/nuts. But we don't see any rust down here. (rarely do I see cars from elsewhere that have much rust either) If using hand tools, or if you're in an area that has to deal with rust and corrosion, you my need to raise the engine a few mm (not very many mm!) as suggested above.

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Thank you!

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Take a picture of your rear bumper and the exhaust Outlets before you start. Sometimes they're drooping pretty good. Probably need to unplug the mass air flow sensor at the air box to get the airbox out. Don't be surprised. That can be the hardest part of the whole deal until you figure it out and then it's no problem. Wouldn't hurt to block the front wheels and put the back wheels up a couple inches on 2x4s. It's easy to do and gives you a little more room when you're looking around your first time.

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That's a good idea.

I like the idea of not jacking the car up. What I don't like is that the nut on the underside is well... under the car and the car is low profile. So it can be done, yes but be sure to lose some weight, change your clothes, wear gloves and safety glasses because no telling what's going to fall on you when you're popping the nut off. Impact wrench is your friend here. They're not torqued too tight.

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+1 wear glasses - i'd probably not do that stupidly.. -1 don't have a impact wrench...

Drive the rear wheels onto some dimensional lumber if you need more clearance to get underneath. With the jack in place, your goal is to unweight the engine from the bottom nuts of the mounts. Make sure you have the jack centered under the engine (left to right) or one side might drop a little bit when you remove the nuts. In that case it can be difficult to thread the nut on the other side after the replacement. You might need a second jack to lift that side high enough to get the nut started. Been there. Done that.

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You don't know what you're missing. I have found that I use pneumatic tools more frequently the older I get. But I recently purchased a Milwaukee M18 1/2 mid-torque impact wrench. It's not too bad. Definitely great for road-side use. The M18 mid-torque is about like my 3/8" Snap-on impact wrench torque-wise. (usually enough, but just barely) For the tough stuff I always grab my 1/2 Snap-on MG725 impact wrench. I have never had it NOT be able to get something loose.(unless it couldn't fit a tight workspace)

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Wow M18?! I use the M12 stubby almost exclusively. I freakin love that thing. M18 seems like a tad too much �ugga dugga� for some M8-12 sized bolts. I even use it to bust lug nuts free. Although the M18 would be sweet to have for suspension work.

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A DeWalt 1/2" 20V impact gun took the rear axle nuts off my targa. Yes air might make more torque, but I'd imagine that you're working in semi tractors at that point. Battery stuff has come a long, long way.

Hmmm tools.. maybe a trip to Home Depot today. What should I buy ( i have Makita batteries currently)? (I don't have a torque wrench yet either...)

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You can never have too many tools, I'm sure you will find something.... Being able to use tools to make/fix things is what seperats us from other Primates

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You should have spent the extra money and gotten Milwaukee's big boy version. It will do anything your pneumatic Snap-On can. I haven't touched my air tools in 7-8 years. I've pretty much gone all in on Milwaukee M12 and M18 stuff. Amen!!

Don't let them scare you too much. Sure it's nice to have all that stuff but mine were fine with a standard ratchet and socket. Primitive but more than adequate. I didn't have to spray them beforehand either. It's an easy enough job. If you run into trouble then you can reconsider.

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Nice to see people still listen to cassettes!

These might make the job easier and come in handy in the future� https://www.walmart.com/ip/RhinoGear...8?athbdg=L1200

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oh nice, maybe better than some 2x4':s . And they're available local

Nothing handier than a stack of 1,2,3' long sections of 2x6 boards. The 100 porsche projects book has a ton of the small items in it and a lot of pics. VERY handy.

Impact will save you time, but you don't need it for this job. Get a good torque wrench. If you need more grunt, buy a rubber mallet to bang on your ratchet, and remember you can always take the end of your jack handle off and put it over the end of your ratchet if you need more leverage. Happy wrenching! Edit: I still feel like the $3 rubber mallet is the most bang for the buck tool you can buy haha

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I originally bought the M18 1/2" drive impact for the crank bolt on a Honda SUV for a timing belt change. My pneumatic impact couldn't handle it. I also have a M12 1/4" drive impact for the small stuff. I have to confess that I don't really listen to cassettes anymore. I was feeling nostalgic and had dug out a bunch of mix tapes that I made back in the day. The cassette player is in keeping with my old school audio theme in the workshop.

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1200 ft/lb is tough to beat. But I do like the M12 and M18 line. I can also use torque sticks on the Snap-on pneumatic impact wrenches. Electric impact wrenches don't work with torque sticks. (impacts are too quick for the torque stick to reset) The mid-torque M18 is fine for track use/away from home. That and a 1/2 ratchet with a cheater pipe and I'd probably be set for most bigger repairs. Although if the mid-torque can't break it loose, I'm likely towing home to fix it there.

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I'm not a fan of using cheaters with ratchets. If I need extra leverage I get out the breaker bar and slide a pipe over that. Probably just me.

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Yeah, that's what I meant, breaker bar and a cheater pipe.

996 engine mounts, easy job, no problem using a ratchet. IMO, why not take a few more minutes and raise up the rear enough to make it more comfortable easier access to see exactly what you're doing..? But if you can comfortably worm in there without lifting the rear a little, all the more power to ya..... As long as we're talking quality air tool vs quality LiPo , another vote for Milwaukee. Used air tools for decades, now they haven't been used in many years. My newest 1/2" Milwaukee Fuel is advertised for 1400 ft lbs torque. Not sure if this is accurate real world torque, but... My neighbor borrowed it and came back with 3 twisted off wheel studs/nuts in his hand from his F250 and said tool is no good, to strong. Showed him how to turn down the power and feel it out instead of full throttle till it snaps. Milwaukee Fuel impact also has a bolt removal mode that applies just enough torque to break fastener loose.. no reason to twist/break things off... Actually my 18v 3/8" impact Milwaukee Fuel puts out 600ft lbs and takes off wheel studs/nuts no problem. Not sure what fastener on a 996 would need any more than the big 1/2 Fuel... My Ingersoll Rand air impact seems not as strong but is a little lighter maybe... its still way stout enough for anything I've ever needed with ease, but needs a air line dragging around to use it. Big Milwaukee Fuel feels like better control of the torque imo, also easier to get the angle straight on the fastener without an air hose to account for. If in a all day long constant professional use maybe the air line would be the better choice over changing out a few batteries a day idk.? They're both time saving tools, but for me the Fuel LiPo impact wins out every time for ease of use, just pick it up and do it... No air line connection to drag around the shop, no lubing the tool before use, no compressor and all the maintenance/cost that goes along with a shop air compressor... Quick change long lasting battery tech of LiPo batteries brought a new era to power tools. Think I could break loose a train wheel with my new 1400ft lb 1/2 Milwaukee Fuel impact, its an absolute beast. jmo

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I like this. Sounds so simple. I had my Indy do it, and the tranny Mount, which I believe is harder. He was in there anyway, doing the rms ims and clutch. The icing on my cake (and it is my cake, you might prefer more or less icing) was when I installed one of those poly damper shims, u know the purple people, into the transmission mount. I'm still not 💯 happy with the shifting, but the new mounts, the FF Shift right, the Raceseng titanium alcantara stratos ****, the sexy sexy alcantara w red racing stripes shift boot, and the new fore aft shift cable connector, I have nothing to complain about. Would I try different, yes, why not. Something that raises the **** up to me closer, but doesn't result in a flexy mess. No rush tho. But none of those updates would have helped much if the drivetrain was sagging to the ground. Get those mounts done folks. See, I didn't hijack the thread, I came back to motor mounts☺️

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Well not off to a great start. Supported engine with centered jack and 2x4 - but when I took off passenger side 18mm bolt engine dropped a good 2-3" so there is likely no way I'll have the thread room to get the bolt on. But then also when i tried to screw in the 13mm top bolts to 17 lbs, the bolt got rethread and squeezed and ruined. I think I didn't 'lock' the wrench, and maybe that allowed far more torque (or at such a low setting, the clicks were not noticable). So now I have to go find a replacement bolt and probably a second jack. Well guess I shouldn't have expected my first diy to go without problems Is it possible I damage the threads inside the carrier for that bolt? Since the mount is all downward force, does the bolt really do THAT much besides keep the mount from moving laterally? Wondering if I can put it all back together, with old bolt. Not drive it, but at least give me time to go find a replacement - and then just swap it out, which wouldn't require removing lower 18mm bolts...? EDIT: I had no choice but to jack the engine up from center to get it back up. Passenger side still a lot lower than driver, but I an atleast get the 18mm bolts no now. I used the the bad bolt for now, but I didn't feel comfortable leaving the car with the engine loose while I hunt down another bolt.

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Well, I'll try to help... Don't let this get you down, its a learning process. If you have perseverance, you'll be fine in the end and know jobs are done right. jmo

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If those are zinc steel and they're bolted into aluminum, chase those threads and get new bolts or clean those up. Brake caliper bolts are of these materials on our cars I think, same drill.

Follow up #2 - (still curious if using that bolt above is okay just temporarily) I had to jack the engine up quite a lot to get the threads visible underneath. Way more than a few mm's as previously stated. I wish I had put more into jacking the engine point up more. The engine dropping when the first bolt was removed freaked me out, I assume on jack stands this wouldn't have occurred, not sure if related to car resting on suspension. The extra 2" on the 2x4's was super helpful. I rethreaded and stretched a 13mm top bolt out of nervousness. Now have to go find one. The passenger side exhaust is slightly lower than the driver side. Unsure if related to the drop or if the engine is slightly lower on one side than the other. Once it was all free, I moved the jack over slightly and jacked up on the passenger side thinking it would free up some extra threading, but it was still at 63lbs. I'm amazed that the engine is supported by just two 18mm nuts! Now that I see how it's put together, it's crazy those two nuts stop the engine from falling out ! Pics of how much threading is left - I don't know how to tell if the engine is as high as it can go. PICS: Before and after from rear. Old and new mounts. And final thread remaining on new mounts after torqued down.

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Thanks for the reply, but i'm not sure I understand well enough what to do... Find a brake caliper bolt?

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Thanks. I did screw in by hand but when i switched to the torque (manual) it just kept turning and turning with very little force. But yes, inexperience I guess... I had read only jack up a few mms to support where the engine was currently, But It really needed a lot more than that. Which I found when having to jack the engine up high enough to get the 18mm nut on. " From your pic, get a new bolt, and chase the threads with a tap and see if you can then hand thread it in all the way...." Can you explain what this means exactly? Chase with tap?

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Sure, tap & die are tools that make threads or used carefully can possibly 'chase' threads clean of buggered up threads. A new bolt should be fine so you won't need to use a 'die'. The threads in your carrier were what you seemed to be concerned with. So try the new bolt, if it threads in by hand easy all the way, you're all set. If not don't force it. Use the appropriate size 'tap' to clean/chase the threads, then brake clean in the hole hard, follow up quick with air to blow it out and see if you can clean them up.... Ya, the 2 nuts holding that end up is an ingenuous engine mounting system for sure. Plenty strong enough. Makes track swaps quick and easy. Thats why the mount end is to a point, for easy find the hole jack ins.

Replace that bolt. While you're at it replace them all. You probably didn't actually lift the weight of the motor off the mounts. If I were doing it your way I'd jack the motor up until I saw the body of the car start to lift, then back down a tad. Hang in there!

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In this pic, the tap is on the far right and is used to cut threads in a newly drilled hole. The gold anodized thing next to it is a 'thread chaser' and is used to fix buggered threads. Either one should work for you. Are you in San Diego by any chance? If so, you're welcome to borrow mine and I even have a correct bolt you can have for free.

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Per 2, yeh this is why I started the thread to begin with, my gut said "if you just support the engine and then remove the engine from the chassis, won't the engine kinda stay put but the car will go up because of the suspension now supporting less weight? I didn't know how to ask that fully though --- and still not sure if that's what is happening/happened. In retrospect when doing this on the ground, not jack stands, one needs to really jack the engine up a lot more. Which is what I had to do in end, I just wish the "drop" didnt happen.

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Thanks guys, I'm going to leave the airbox and air pump out, but keep the engine bolted. And try and find four new bolts for top. Hopefully receiving side is okay, otherwise will find a tap (I'm in glendale, a bit of a drive to SD, but thanks). Pelican might have the bolts, I'm sure theyre $85 a piece i'll likely just start over again. Jack the engine up 3" so its pushing the car up. Undo the 18mm nuts, jack it some more to make sure up high enougg, install top 13mm bolts, install lower 18mm nuts (which I'll clean). Then hopefully left and right side will be even (right exhuast is a cm-2 lower than left) (unless above is over kill)

Part # and description. Just go or call your local dealer. They will have the bolts next day. Hex-head Screw 8x40 - Genuine Porsche90037805501 Also its common to have to adjust the exhaust tips after swaping motor mounts.

If you have the motor mounts properly installed and torqued, the exhaust unevenness is likely due to a tailpipe not being aligned properly. You can loosen the exhaust clamps and position the tips where you want.

Ensure the square part of the new motor mount fits in the square recess in the bracket on the engine. It *should* just drop in, though it is a good idea to check.

All good advice on here. I did this over the summer while replacing the coolant tank. A couple of hints: As others have said, PB blaster is your friend. I soaked mine for a few days with multiple squirts until I did it. You will need a deep socket, 18mm. This was a gotcha for me. Although I have several different socket sets. Apparently 18mm sockets are not in all sets and I did not have a deep one. Ordered from amzn. Although I have air and electric impacts, I tend to avoid using them due to fear of braking things and actually making the job longer. I used a breaker bar with a pipe on it to break the nuts loose. I had not supported the motor yet. I did mine on my 4 post. I know I wouldn't fit under there to crack the bolts. Raising the rear will be very beneficial IMHO. Each mount has a correct way to go in and a not correct way. It is obvious when you see it, or take a pic before removal so the replacement is positioned properly. I did the first on correctly and made an error on the other side, although before I tightened anything up. My replacement engine mounts didn't come with any stickers, so my car didn't gain any hp or speed lol.

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Curious how they can go in wrong? I've tightened everything up, but where would it be installed incorrectly?

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To tell you the truth, I'm not sure. I hadn't tightened anything up. When I was about to start tightening, it just didn't align or settle properly. I rotated the mount 180 degrees, all was good. Interestingly, the first one was fine, I'm not sure what I missed on the second one.

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If you haven't 'clocked' the mount correctly bolt holes won't line up, it only fits 1 way... Also seems its relevant to mention the best way is to torque/mount the engine mounts in the engine bay first, before the big nuts from below are tightened at all. That way you can move the mount slightly around to align holes taking any side pressure off the top bolts. This allows you to screw them in by hand without damage to the threads from the mount being pulled/pushed/or cocked to the side from below if engine isn't jacked up and centered correctly... Once the top bolts are in correctly and torqued correctly,,, you can man handle the bottom nuts/studs like in a engine swap race track pit stop. They are stout heavy duty fasteners... jmo

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On the ground or on jack stands makes no difference, except your jack would have to span a greater height if the car was raised. The engine hangs from the frame, not from the suspension.

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I'm asking this from ignorance, but doesn't the weight of the engine pull down on the suspension? So if the weight of the engine is now free, don't the springs of the suspension push the car up, in which the engine essentially stays in one place? I'm probably totally wrong in that reasoning, but it's why I had to jack the engine UP into the car after the fact, and I assume the distance between the tire and the wheel well was slowly decreasing as the suspension was absorbing some of that lift from the engine moving upwards...? I had the engine pretty snuggly propped up on the jack, and there was 2-3" of drop of the engine (or lifting of the frame) when that first bolt came off, and I'm pretty sure the jack height didn't change at all (otherwise that would be a HUGE problem if the jack dropped, and I had it securely tightened). I'm asking because I'm getting four new 13mm bolts tomorrow so will do this over again and rather not repeat that experience

Why dont u just take each of those bolts out 1 at a time and replace. No reason to remove the large not that holds the motor.

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The engine will stay in the same place relative to the engine bay no matter what the load on the suspension is. Completely separate.

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The only reason I'm thinking to start over is because now I'm not sure if the engine is as high up as it needs to be. I had to jack the engine UP into the car because the long main mount bolts were 2 inches from even being close to coming out of the lower frame mount. So I don't know if there is more room to go. I did torque to 63lbs, so if that's all there is to it, then maybe I won't bother. First time gitters... I feel like I'm totally missing something here having done it on the ground as opposed to jack stands or a lift. I still don't get why the suspension doesn't relax when the weight of the engine is removed. Don't the wheels drop away from the frame when you lift the body? Doesn't that exact same thing happen but in reverse when you remove the weight of the engine, doesn't the frame go UP because the engine could essentially go DOWN if it weren't supported by the jack? I'm not questioning anyone, my newbie brain, and lack of technical understanding of suspension is to blame (and to think I want to do a 100% suspension refresh next, though maybe I should rethink that )

U need to stop thinking so hard about this simple repair. If the nuts r torqued to 63lbs then the motor is where it should be. U can use an inspection mirror or a edoscope camera make sure the square in the mount is seated correctly in the mount but its hard to mess that up with factory parts Yes if the tires r in the ground and u unbolt both motor mounts u r reducing the weight on the suspension so the car may rise slightly. So the amount of load on the jack will change some as u release or tighten the motor mount bolts.

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Check out this video if you haven't already. Maybe it will clarify things. I did mine 5 years ago so I don't remember if I followed their procedure exactly. You Tube

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Yes, I'm def over thinking, but also YES, that's the answer to the question I was asking: the car did rise 2-3" - and thus the engine needs more vertical support to offset the suspension change when doing on ground verse when doing off ground. Yes, I followed that video - well except for being on the ground and not on stands/lift. ---- I think I'm good. I'm going to get my new bolts tomorrow, and just swap them in one by one. Appreciate everyone's support.

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You have that backwards. If the tires are off the ground your jack will have to travel higher to unweight the engine from the nuts.

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No what I mean is, the instructions everyone says is: the jack should just support the weight of the engine a few mm's, NOT lift the car. But if you're doing it on the ground, you DO need to lift the car a bit to offset some of the suspension difference from when you remove the weight of the engine (which is pulling the rear down) from the frame. So you need to jack up the engine higher than if you were simply supporting it.

There have been lots of threads on replacing these mounts� For what it�s worth, I remember jacking up my engine quite high - enough to nearly lose clearance inside the engine bay where stuff was nearly hitting the top of the engine bay.

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You are obsessed with this idea but it's wrong.

One way to think about it is to just lift the engine to the point where it is designed to be so that there's no weight on the mounts and you can more or less loosen or tighten the nuts on the bolts by hand. That way you avoid letting the lump/motor down by the bolts when removing the mounts or lifting it up by the bolts when installing the mounts.

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I do get obsessed I guess why this scares me so much, and why I'm harping on it, is what you're saying is the jack failed and dropped 3" when the engine weight was fully on it. Even with it fully locked out and secured. De Jeeper said in a comment above the car would rise when removing the weight of the engine (thus making it appear the engine dropped), but you're saying that's not possible? I guess all I have to do is do it over again, and record it.

1. Support motor just support DO NOT LIFT THE MOTOR!! (This is all easier if you have the car rear tires on 2x6 boards stacked 3 layers high. ) 2. remove bottom large nuts on mount. (Mine was drama free... ) use a breaker bar and a 14" extension worked for me to just break loose, then used my 1/4 dewalt impact driver to spin them off.. . 3. remove the two bolts on top, pull old mount out 4. Insert new mount, make sure the square part on the bottom side goes in the square hole. 5. put the top bolts back in. 6. Put the 2 new nuts you bought with the mounts on. (Not required but for the money and the less chance of corrosion....) 7. Beer time. PS, once all the bolts are out, you may get some side to side rocking, just from balance. as long as the cross bar/mount is still touching and you can see through the holes and get the square boss on teh base of the big bolt coming out of the mount lined up your golden. Mine was easy.. Total time. about 30 minutes.. I can't change the oil in the time this took.. YMMV!