986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Replaced Engine Mount - Pics of Old and my Mount Mystery

JoeFromPA · 03-31-2011, 04:26 AM

Hi all,

I replaced the front engine mount on my 99 boxster. The job itself was not hard - I'd recommend doing it at the same time as the fuel filter and, if at all possible, the coolant/thermostat. Here's my tips for those who haven't done it:

1. Drop the plastic undertrays, take both plastic straps holding the coolant tubes in the tunnel off (allows the hard plastic coolant tubes to move around alot). If you are smart, go ahead and drop the large coolant hoses too and just replace the coolant when you are done.

2. Make sure you have a 3/8 and 1/2" ratchet (or a adapter), 6" extensions for both, a 15mm and 7mm socket.

3. Buy a 15mm flat ratcheting wrench....for the love of God, buy the ratcheting model.

4. When done, put the new mount back on the engine and tighten, then jack the engine back up (easy to do with a quality jack since the engine doesnt put alot of weight on it), then thread the engine mount YOKE studs through the yoke into the chassis using a 7mm socket (it fits onto the head of the stud). Make sure it's fully seated. Then put the nut on the stud and tighten. Slowly tighten one on each end, then do the same in the middle. Make sure the yoke is fully seated against the chassis. Tighten these with a torque wrench....they are delicate threads and will strip out of the chassis.

...

So, here's my old mount - 59k miles, not really driven hard for most of them:

------------------------------------------

Now here's my mystery: the mount I pulled off the car had a solid-face style of construction and mounted using only 3 bolts to the engine.

However, according to online sources, Porsche only used the solid-face mount from 97-98 and then moved to a grid-style. I have a 99.

Further, according to online sources, if i had a 3-bolt style mount I should have the 3-bolt style housing - I should not have had a 4th bolt hole in the engine nor a bolt there. But I did - I have the 4th bolt hole AND I had a bolt there....

And it gets better - the bolt that was in the 4th hole was improperly sized for an engine mount. It looked right, but it was threaded from top to bottom and was not long enough to grab the engine through the mount. It'd only be threaded without the mount there.

Here are pictures of the old mount face and part number:

So what's going on here? My father bought this car in ~2002-2003 with 30k miles on it from CarMax. I don't have the maintenance records before that time. Either this is the original mount, or the mount was replaced back in the early years with a mount from an earlier model.

The only way I can figure that happened was if this got an engine replacement, and they had a variety of mounts sitting around. Engine replacements were certainly common back in those days.

Am I totally off base here? Is this really the original and I've just spun a tale? If I'm on the right track, any suggestions for how I figure out if this car had some sort of major engine work done to it?

Thanks all.

Joe

P.s. I also think this mount was replaced in the past because two of the studs stripped out of the chassis on me. Now, I could've been attacking them wrong, but I wonder if they were previously cross-threaded or way overtorqued with an air tool.

Car'll lightly drive and idle just fine with only 2 studs/nuts holding the yoke to the chassis....and both of them on only one side of the yoke! Taking it to my mechanic today to get it sorted out.

Edit P.P.S. I just noticed again how "fresh" the bolts going through the original mount look in the above photos. Hrmmm...

03-31-2011, 04:26 AM	#1
JoeFromPA Registered User Join Date: Jul 2010 Location: West Chester, PA Posts: 211	Replaced Engine Mount - Pics of Old Mount - And a Mystery for the Experts Hi all, I replaced the front engine mount on my 99 boxster. The job itself was not hard - I'd recommend doing it at the same time as the fuel filter and, if at all possible, the coolant/thermostat. Here's my tips for those who haven't done it: 1. Drop the plastic undertrays, take both plastic straps holding the coolant tubes in the tunnel off (allows the hard plastic coolant tubes to move around alot). If you are smart, go ahead and drop the large coolant hoses too and just replace the coolant when you are done. 2. Make sure you have a 3/8 and 1/2" ratchet (or a adapter), 6" extensions for both, a 15mm and 7mm socket. 3. Buy a 15mm flat ratcheting wrench....for the love of God, buy the ratcheting model. 4. When done, put the new mount back on the engine and tighten, then jack the engine back up (easy to do with a quality jack since the engine doesnt put alot of weight on it), then thread the engine mount YOKE studs through the yoke into the chassis using a 7mm socket (it fits onto the head of the stud). Make sure it's fully seated. Then put the nut on the stud and tighten. Slowly tighten one on each end, then do the same in the middle. Make sure the yoke is fully seated against the chassis. Tighten these with a torque wrench....they are delicate threads and will strip out of the chassis. ... So, here's my old mount - 59k miles, not really driven hard for most of them: ------------------------------------------ Now here's my mystery: the mount I pulled off the car had a solid-face style of construction and mounted using only 3 bolts to the engine. However, according to online sources, Porsche only used the solid-face mount from 97-98 and then moved to a grid-style. I have a 99. Further, according to online sources, if i had a 3-bolt style mount I should have the 3-bolt style housing - I should not have had a 4th bolt hole in the engine nor a bolt there. But I did - I have the 4th bolt hole AND I had a bolt there.... And it gets better - the bolt that was in the 4th hole was improperly sized for an engine mount. It looked right, but it was threaded from top to bottom and was not long enough to grab the engine through the mount. It'd only be threaded without the mount there. Here are pictures of the old mount face and part number: So what's going on here? My father bought this car in ~2002-2003 with 30k miles on it from CarMax. I don't have the maintenance records before that time. Either this is the original mount, or the mount was replaced back in the early years with a mount from an earlier model. The only way I can figure that happened was if this got an engine replacement, and they had a variety of mounts sitting around. Engine replacements were certainly common back in those days. Am I totally off base here? Is this really the original and I've just spun a tale? If I'm on the right track, any suggestions for how I figure out if this car had some sort of major engine work done to it? Thanks all. Joe P.s. I also think this mount was replaced in the past because two of the studs stripped out of the chassis on me. Now, I could've been attacking them wrong, but I wonder if they were previously cross-threaded or way overtorqued with an air tool. Car'll lightly drive and idle just fine with only 2 studs/nuts holding the yoke to the chassis....and both of them on only one side of the yoke! Taking it to my mechanic today to get it sorted out. Edit P.P.S. I just noticed again how "fresh" the bolts going through the original mount look in the above photos. Hrmmm... __________________ 99 Boxster 5spd - 64k miles 06 Civic SI - 114k miles, D.D., unbelievably reliable and fun to beat on everyday. 08 Legacy GT 5spd - 74k miles. Last edited by JoeFromPA; 03-31-2011 at 10:13 AM.