Engine mount inserts ... don't !
 

Hi !

Today, I decided to finally change my engine mount.
It's not the hardest of job, took 1h20min.

To replace my really really bad mount, I chose the updated 987 mount, and Torque solution insert instead of the OEM stops (the inserts were actually cheaper @ 49$).

Well... don't do the same mistake ! The car is undrivable ! It shakes so much that I wonder how I managed to go back home !
Plus, the vibration foul the knock sensors and the car has no power (no CEL).

The inserts squeeze the mount in the carrier so tight that it's basically a solid mount now

Sure, I got rid of a lot of the play in the shifter, which feels even more solid now and shifts beautifully. But I don't see how you can drive this !

So tomorrow I'll have to take the engine mount out again, and cut/grind the inserts so it fits like the OEM one because the dealership did had any stops in stock ...

Conclusion... for your engine mount, buy OEM !

Ben.

I have a powerflex engine mount insert in my other car right now. I thought the same thing when I installed it and went for a ride. Almost unbearable. Before you remove it, give a few days to settle in and the NVH will lessen.

that's what I tought at first, but it's really really rough.

Was your insert really tight ?
I had to use WD40 and a lot of force to put the mount back in the carrier !

The thing is that i'm afraid that it might cause some damage to something or loosen something :/

Thank you for the feed back !

Edit:
I just went on their website and noticed that they were close to were I live !
I'll give them a call or visit them tomorrow !

Thank you

Yes, it was VERY tight. The ride back home on the highway I was thinking "what the hell did I do to my car?!". But soon after it settled down, and its not really any worse than stock.

Keep in mind this isn't on a boxster and how much it settles depends on the durometer of the insert, but that was my experience with engine mount inserts.

Ok, we'll see then.
I've sent them a mail to see what they say about it !

Thanks ;)

No answer from torque solution :/
So I took the lead and ground the insert flat so they would fit perfectly inside without being too tight.
It took 20 minutes from the time I took my toolbox out and the time I had the mount out. 40 minutes to grind the inserts on a bench grinder (and clean the mess that I just made), and 15-20 minutes to put the mount back on !

Now the car feels really good ! like a new car (new flywheel, clutch, ims, tires, and engine mount :) )

I had a similar experience with the WEVO semi-solid mount - its SEMI-solid, so my thinking was that it should be firmer than stock but softer than a solid mount. Boy, was I wrong! The semi-solid mount felt like a solid block of aluminum! The side mirrors vibrated such that the image was blurred when sitting still at idle. Changed back to stock and learned the lesson.

Been in a Cayman R with a semi solid mount and it was awful at anything other than 4K plus.....hard accelerateion / wot i can't recall as the fear of smacking the walls of Mosport was in me.

Generally, I would think the extra vibes you are going to get would be disruptive rather than help you on track. Just put the stock 987 one in there and all will be well

Ben's experiment/mod suggests that perhaps there was a manufacturing error in the molding of the insert ? For example, over filling the mold with PU foam.
Seems his vendor is not the only one to make a similar error.

No manufacturing error, more of a design error.
If I were to make an insert, I would leave some compliance, but there was none.

I ground it to mimic the stock stops shape.

First the Shifter now Ben - do a motor mount insert ?

Perfect post! I was looking for some feedback as I took my first drive with the Powerlex engine mount insert. I thought as you did. Unbearable! I was very close to ordering a stock 987 mount until I saw your post lol. The NVH seems to be coming from the front mount. Mind you, I have the Rennline transmission tuneable blue inserts as well. Has it smoothed out any further? I'm very curious about your findings. Thanks!

Never use aftermarket engine mounts!
 

The OEM engine mounts are the only way to go.


Just think of them as a wear item that your replace regularly.

All of the aftermarket engine mounts that claim to “firm up shifting” et. al., are disastrous.

Even if you get a “slightly” firmer one, they ALL trigger the engine knock sensors and you will actually LOSE horsepower and torque. I have seen it on the dyno.

Just stay away from them all.

Good luck.

Hey 10/10ths,

If a knock sensor is triggered will I get a code? How about semi-solid trans mount with the 987 engine mount?

I have the soft function first insert and my knock sensors are not showing any activity.

Powerflex has a series of engine mount products. I have the "Street Series" yellow bushing installed. It's not an 'insert', but replaces the entire bushing in the stock mount. I have no complaints in my '97 2.5L and will be putting it in my other cars as they need replacement.

http://986forum.com/forums/uploads02...1606841111.jpg

That's the one I have. Did you feel it was less abrupt after awhile? Maybe because it was my first drive and the combination of my transmission mounts..

I filled the voids of an OEM mount (front mount) with urethane. I'm not sure I can tell a difference, really.
ymmv.

I didn't notice any increased vibration as compared to a new 'Lemforder' replacement bushing that I've used in the past as a replacement. Most of the engine mounts that I've replaced have been done soon after purchasing a car and the old mounts were shot. That makes it hard to do a head to head comparison, but I'm quite satisfied with the Powerflex bushing.

Pics because I like to post pics...
http://986forum.com/forums/uploads02...1606921166.jpg

http://986forum.com/forums/uploads02...1606921229.jpg

Thanks for the feedback. Strongly considering the Powerflex bushing myself.

No codes....
 

....you will just lose power.

The stiffer motor mounts trigger the knock sensors and the engine management will retard ignition timing to prevent what it thinks is detonation.

I’ve seen dyno tests to prove it.

I promise you that every Porsche out there with inserts or polyurethane bushings in their motor mounts now own slower cars.

So if you want more noise/vibration/harshness AND a slower car, by all means, send your hard earned money to the aftermarket purveyors who feast on all of the uninformed new Porsche owners who are now buying these old cars because they have depreciated to the point where they are cheaper than new Corollas.

You have been warned.

Just don’t do it.

Cheers.

If that's the case - and I'm not arguing, I'm enjoying driving my slower car fast.

Are any of the dyno comparisons documented and available? I enjoy reviewing details and statistics to to learn and arrive at my own conclusion.

If you can see the effects on a dyno, I would think you would be able to see this in durametric. Should be easy to test I think. Can you see what the cams are doing live with a durametric? I don't have one, so not sure. If so the ecm should be pulling timing when detecting knock right? Drive around with durametric running, what does the timing do?

Question, do porsches of this year show 'pending' codes? My other cars do, but are newer canbus cars. I would think there would be at least a 'pending' code if it detects any knock at all, then sets a full blown code once it hits the requirements (whatever those are, detection during a certain # of drive cycles, etc).

I'd be imlpressed if somebody has done back to back Dyno runs on the same car showing before and after a change of engine mount and has posted the plots for consumption!

Hey 10/10ths.

I will be pulling my Powerflex engine mount. The vibration is too harsh coming from this area. Question for you. When you say lost of power from engine mounts, are you saying Transmission mounts as well?? I have Rennline trans mounts and I'm not sure if I want to pull those as well.

By the way I have a Durametric. I didn't see any underlying codes. Maybe someone can direct me what to look for if theres a knock sensor issue. Thanks.

You wouldn’t get a code, the timing would be retarded by the DME when it senses the vibrations the mounts transferred to the chassis, assuming it was actually pre ignition, but as soon as the vibration stopped, the timing would return to normal. You would need to catch the timing in real time.

Hey JFP,

So when you say real time do you mean while driving? Anyway to monitor it with the Durametric while driving? What about the transmission mounts? Do they aid in retarding the timing? Any insight is much appreciated. Just trying to decide if I will keep the transmission mounts. I'm definitely taking the front mount out.

Yes, the durametric will allow you to monitor any systems while driving. I understand that there's also a utility to record a session, though I've never used that feature.

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I've used the Durametric for other issues, but I'm not sure which feature to select for the knock.

My main concern is the transmission mounts. I want to know if they have an effect on the knock as well.

Well to be honest, I don't think that you can monitor the knock sensor directly. I think you'll be looking for the DME's RESPONSE to knock.

I'd watch for things like ignition angle, for instance.

JFP may know more.

I've used mine mainly for watching the o2 sensors and the fuel trims. (And cam deviation, etc).

To be honest though, I seriously, SERIOUSLY doubt that you're going to be able to demonstrate that the knock sensor is being triggered by the engine mount. I just don't believe it is, so I don't know how you'll demonstrate that it is.

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I gotcha Maytag. I'm not sure what to think to be honest.

Are we talking the inserts or the replacement bushings they offer? My understanding is the replacement bushing largely feels like stock, maybe a little more stiff, but that the inserts drastically increase the stiffness. Is this correct?

In the Durametric system, you can see the amount of ignition timing; if vibrations triggered the knock sensors, the timing amount would suddenly step down until the vibrations fall off, then the timing would come back up in a step like function. You can set the Durametric system up to record the timing and take the car for a run.

Solid or near solid engine mounts can trigger this phenomenon, transmission mounts less so because they are further away from the sensors.

Thanks JFP,

That answer my questions. I will most likely set the semi-solid trans mounts to the softest setting and take out the front engine mount. Thanks

My question is this, why do race cars have more aggressive mounts? Does it detract performance as well?

Thanks.

Race cars typically either remove the knock sensor or disable them as they serve no purpose on a race car; and quite often run an aftermarket computer as well. And race cars run either very hard or totally solid mounts as softer mounts actually consume some HP that would other wise be transmitted to the rear wheels. Racing is a totally 10 tenths world, were small differences add up to winning or losing.

Competition cars and street cars are two totally different worlds, and neither one tends to do well in the other's environment.

Gotcha, thanks for the detailed explanation.

Oh just want to piggy back off of what JFP said about softer mounts consume HP. That's why I changed my mounts so I can put the power down to the ground better. Honestly I'm not sure if I can feel a difference.

And...
 

....just to tie a ribbon on this, a street car makes a lousy race car and a race car makes a lousy street car.

A lot of these aftermarket parts that people think will improve their street cars actually make things much, much worse on the street in the real world.

Now I’m done.

yup! Applies to aero as well. What you think looks good can reduce performance

You live and learn..