Vibes from Poly Motor Mounts

turbojimmy

Supporting Member
Joined
May 26, 2001
For those that are using HRPartsNStuff mounts, what kind of vibes are you getting?

I'm cool with vibration if it's normal, but I'm thinking it's not. Ever since I put the engine back in (with said mounts), it vibrates something fierce at idle, and worse just off idle. Smooths out at speed. The glovebox door rattles as does lots of other things I can't identify.

Do I have something out of whack?

TIA,
Jim
 
Ive got both sides with the polys, and they rule. If there is any vibration at all in mine, these things are too awsome to tell:D What i love the most is when im under the hood and i rev it from the throttle latch, just to see my engine NOT move a hair!!! NO tie down strap necessary when these things are in place:D

jojo
 
Originally posted by jojo
Ive got both sides with the polys, and they rule. If there is any vibration at all in mine, these things are too awsome to tell:D What i love the most is when im under the hood and i rev it from the throttle latch, just to see my engine NOT move a hair!!! NO tie down strap necessary when these things are in place:D

jojo


what jojo said :)

I have both mounts
 
I've seen several posts regarding the poly mounts & vibration. Alot of guys just use a poly mount on the drivers side because that's where it's really benificial.

Unless I'm mistaken, your car has t-tops correct? If so, that may very well be why the vibration is so noticeable. T-top cars are just not as solid as hard-top ones...if you know what I mean.

I have heard that after a while the vibration seems to dissipate somewhat. Whether the poly itself softens up just a bit or you get used to it...I really don't know.:)
 
I have an S2 that's balanced different than the stocker I think (50% ?), but vibration hasn't been a big problem on mine with the HR mounts. And a poly trans mount too. You CAN see the engine torque over with 'em on a chassis dyno however, especially when the hose comes in :)

TurboTR
 
I have a hardtop GN, I also had the motor balanced. I have a vibration just off idle too, goes away with rpm. Not too worried about it. All three mounts here. Love em!
 
Thanks for the info everyone. I must have something out of whack because the vibe is severe.

Jim
 
Driver's mount here. I did notice more vibration but you do get used to it after a while. I think Paul said they were working on a softer mount if I remember right.
 
I talked Paul sometime back and asked the same question....
He told me to recheck the torque on the bolt that runs through the mount. I did have someone that works for me install them so I rechecked them. He hit it on the head the bolts going into the block were close, but the one's going through the mounts didn't even come close, I retorqued them and solved 80% of the problem....

:cool:
 
That's a good idea! But wouldn't the engine move around if they were loose? How tight it tight? I noticed that the mounts were bigger than the pads I'll suck them up with the "BIG" gun if I have to.
 
With the soft poly on the driver's side and the stock mount on the passenger side, I could barely notice any increase in vibration, and after driving the car a few times it's completely out of mind.

With the stock OE mounts my car only had about 1/4" clearance between the 3" DP and the heater box heat shield. When I installed both poly mounts, the pipe contacted the heat shield heavily and caused some vibration. I had to remove the passenger side mount and go back to a stock one there to get back the 1/4". Good news is that paul has redesigned and now the mounts are adjustable, allowing the engine to be moved around a little. He just sent me one of the new design driver's side mounts for my wife's T, but I haven't installed it on that car yet.

HR Parts -- great product and great support
 
I had the same problem with the heater box. That was more of a rattle than a vibe. I cleared it up by cutting the bottom of the shield off. This is a rough vibration. Ever since I put the new motor in. I always figured it was the mounts, but I want to go to the track soon so I wanted to make sure everything was okey dokey.

Thanks again - I'll keep lookin.

Jim

PS - love the mounts - not dissin the mounts at all.
 
Russ......

I can't remember for sure it's been several months, but if I'm not mistaken it was 80 ft lbs...
Paul also told me if I had to distort the mounts metal to hit the number so be it. This applied to the long one's that run through the mounts. I can check my directions for sure if you'd like I still have them at the shop...

:cool:
 
Originally posted by Phatman
Russ......

I can't remember for sure it's been several months, but if I'm not mistaken it was 80 ft lbs...
Paul also told me if I had to distort the mounts metal to hit the number so be it. This applied to the long one's that run through the mounts. I can check my directions for sure if you'd like I still have them at the shop...

:cool:

I just caught this posting... PLEASE feel free to contact the manufacturer (me in this case) if you have issues with a new part. We are always glad to help out & make things better. A happy customer is our only customer :)

I am not sure of the torque spec on the long bolt, but the ones into the block get 58ft/lbs. 80 doesn't sound too far off if any. The biggest issue with vibration happens when the side plates on the poly mount don't clamp tight against the stock frame pad. The frame pads are all different in size & shape, so some of them don't bolt right up. If the long bolt holding the mount to the pad is tight, that doesn't mean the side plates are clamped tight against the frame pad. This will rattle much more if it isn't clamped tight. Some cars need a thin washer or 2 between one side of the frame pad & the side plates to allow it to clamp tight.

Our original mounts had "normal" poly bushings, and had a small weld all the way across the part that sits on the frame pad. We found this to be OK on most cars. To let the side plates clamp on undersize frame pads easier, we started to weld only on the ends & not all the way across. We also had a slightly softer poly custom molded up for the prod. 3.8 mounts. We still use the regular poly on the stg mounts due to higher HP potential. Now, we have a spacer pin between the side plates that sits on the frame pad. This lets the side plates clamp on even smaller frame pads. Now our mounts should fit every single car out there, of course someone will prove me wrong :) Basically, the minor % of people that had this issue will be reduced or eliminated.

If you have the earlier mounts that were welded all the way across, you may need to put a washer in there to take up the gap. Now that you already had them installed, you may have to bend the side plates out to get the washer in. Clamp the sides TIGHT! Distort the metal all you need, just like the stockers did. It's just a little harder now that they are thicker & stronger. Hope that does it for you. If not, PLEASE let me know directly so I can help you get it figured out. It's hard to get & keep 100% customer satisfaction, but that's the goal! :)

PS- The difference from having the pair over a single poly mount is actually minimal. You might think that it would double by doubling the mounts, but it is more like 10-20% more. Also, the softer poly makes it slightly smoother, but it is not worth taking the old ones out to swap them. It is just a minor improvement. It might make a bigger difference on cars that seem to have more vibration, hard to say. Every car is different & reacts different to changes. Hope that helps! Oh yeah, they do soften up after 1 week to 2 months of running, depending on how much you drive it. There are some clearances within the mount to be able to assemble it and not make it so tight, and they settle in. Most peole tell me that the vibrations are enough that the driver/owner will notice, but not be annoying or excessive. The passenger, spouse, or friend will most likely never notice a difference. If it's more than that, it's likely the side plates not clamping the frame pads.
Sorry if that was too winded :)
 
Thanks, Paul.

The reason I didn't ask you was because I wasn't convinced - still not convinced - that it's the mounts. I figured I'd start there 'cause I heard people say that the mounts *could* cause a vibration. Doesn't sound like they really cause the kind of vibes I'm getting, though. I'll check the bolts anyway.

Also, as I mentioned before, I'm not dissatisfied with the mounts AT ALL. They are a great, perfectly engineered product. It's awesome not having that stupid eyebolt and strap under the hood.

I drove the car again today for the first time in a while. It's not really bad unless the car is in gear and idling (foot on brake). Vibrates from 0-15 or so and then smooths out.

I'm not sure where to start - everything's been replaced (engine, trans, TC, etc.).

Guess I'll start with the mounts and move on.

Jim
 
turbojimmy....

That's exactly what I went through, although I added the ATR rear sway bar at the same time so I had a completely different ride along with a growl sound at idel and take off.

Paul....

Sorry my good man, I wasn't trying to put words in your mouth, but what you told me seemed to correct most all of my problems.
I couldn't be happier with mine. I'll be getting with you sometime soon on those upper arms.

:cool:
 
Jim, spend a couple hours and put the stockers in. If the vibe is gone, then there was metal interference with the new mounts. This is common with Saturns. The mount squishes as it ages and the 2 pieces of metal *just* touch. This casues such a vibration you think the car is coming apart. May be the case with your car. Something thats supposed to be suspended by rubber may in fact not be.

If inspecting the new mounts and/or putting in the old mounts doesnt do it, try turning the converter on the flywheel, see if anything CHANGES. Make sure the balancer is tight and the outer ring isnt coming apart. Stuff like that
 
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