2001 sw2 - Bad vibration at idle after new motor mounts

16essiju · Jun 12, 2025

Hey guys, got an 01 SW2, my fiance always hated the car due to idle vibrations. So with any old car i replaced the motor mounts with the anchor kit from rock auto, came with upper mount, the trans mount, and the two dog bones. I personally never felt the car vibrate before hand but did it to help my fiance like the car more. Now on start up and if i sit at a light for more than 30 seconds it now vibrates the window crank how bad it is. I scowered both the FB groups and the fourms for extra info, a few guys said about the way i maybe installed the mounts? I started at the top, got it in and torqued, than went to the trans and same thing, finished and torqued it, i did the dogbones last. I replaced the IAC thinking maybe it was messing up the idle now and i had never replaced that before, i wanna get carb cleaner and spray some areas and make sure i dont still have a leak somewhere maybe around the TB, but the gasket looked really good when i had that off to clean and replace the IAC. Any help would be hugely appreciated as i fish with my saturn and now the idle also annoys me.

Derf · Jun 12, 2025

Aftermarket mounts are shyte. Always have been. Put the old upper torque axis mount back in.

You need to support the oil pan with a piece of wood between the pan and your floor jack. Take the weight off of the torque axis mount.

You need to loosen the lower torque axis mount after loosening the upper torque axis mount. This allows the engine to settle into its natural resting place without inducing stress on the torque axis mounts. Install the new upper mount then re torque the lower mount. 90% of The vibes come through the upper torque axis mount.

As far as IAC, now you've changed two things at the same time. When you do that, there's no way to determine what fixes what. I suggest you reinstall the old IAC and clean it first. Then do a throttle body cleaning, then reassemble. Change one thing at a time or you are forever lost in guessing what is affecting what if at all.

Is it automatic or manual and what is the idle RPM when warm?

If you want to check for vacuum leaks, spray choke cleaner around where the throttle body mounts, the EGR, and where the intake manifold meets the head. If there is a vacuum leak, the RPM will increase slightly as the cleaner sneaks in through the leak and is burned. Make sure to thoroughly spray the underside of the intake manifold to head interface as the leak can be anywhere. You can work the throttle by hand under the hood should you feel the need. But get the mounts squared away first. And the idle RPM is usually a big clue as to whether you have a vacuum leak or not.

Is the check engine light on?

16essiju · Jun 13, 2025

Derf said:

Aftermarket mounts are shyte. Always have been. Put the old upper torque axis mount back in.

You need to support the oil pan with a piece of wood between the pan and your floor jack. Take the weight off of the torque axis mount.

You need to loosen the lower torque axis mount after loosening the upper torque axis mount. This allows the engine to settle into its natural resting place without inducing stress on the torque axis mounts. Install the new upper mount then re torque the lower mount. 90% of The vibes come through the upper torque axis mount.

As far as IAC, now you've changed two things at the same time. When you do that, there's no way to determine what fixes what. I suggest you reinstall the old IAC and clean it first. Then do a throttle body cleaning, then reassemble. Change one thing at a time or you are forever lost in guessing what is affecting what if at all.

Is it automatic or manual and what is the idle RPM when warm?

If you want to check for vacuum leaks, spray choke cleaner around where the throttle body mounts, the EGR, and where the intake manifold meets the head. If there is a vacuum leak, the RPM will increase slightly as the cleaner sneaks in through the leak and is burned. Make sure to thoroughly spray the underside of the intake manifold to head interface as the leak can be anywhere. You can work the throttle by hand under the hood should you feel the need. But get the mounts squared away first. And the idle RPM is usually a big clue as to whether you have a vacuum leak or not.

Is the check engine light on?
Click to expand...

Hey Derf, thanks for the reply, as for the old upper mount, it was fully shot, the rubber was dry cracked and i could pry it with ease, plus its already trashed (oops). I did try and loosen the upper mount a bit and than the lower but didnt fully support the engine just touched it with the wood block, i can try that again tomorrow with more weight on the wood. Should i leave the dogbones tight while doing that?

As for the idling issue i actually figured that out with pulling the Throttle Body back out to double check the IAC after work today and realized i forgot to plug that vacuum line back into the backside, after that it went back to the 900RPM idle, does that sound like the healthy idle for these cars? That is what it idled at before.

Derf · Jun 13, 2025

Yes, pass dog bone tight.
Lower torque axis mount has a dog bone in it.
Don't cave in your oil pan. Make sure you distribute the weight across a decent amount of area on the piece of wood that sits on the jack. You are trying to support it just enough to take the weight off of the bolts you are trying to loosen.

When you are done, observe how much the engine is moving around under the hood. Compare that to how much it was moving around before. Not scientific but educational.

If the upper t a m was wasted before you started, it's not clear to me why one of you would notice and one of you would not. The dashboard should have been vibrating and usually you can feel it in the seat. Driver's seat. The vehicle has a bad resonance right around idle RPM, so 900 maybe worse than what it was at whatever the idle was before. Wasn't there, didn't see it, dunno but that is my suspicion. Might have a tiny vacuum leak but usually the engine gets pretty angry pretty quickly as it messes up the fuel mix. Where does your temperature gauge read on the dash when the vehicle is warmed up?

16essiju · Jun 13, 2025

Derf said:

Yes, pass dog bone tight.
Lower torque axis mount has a dog bone in it.
Don't cave in your oil pan. Make sure you distribute the weight across a decent amount of area on the piece of wood that sits on the jack. You are trying to support it just enough to take the weight off of the bolts you are trying to loosen.

When you are done, observe how much the engine is moving around under the hood. Compare that to how much it was moving around before. Not scientific but educational.

If the upper t a m was wasted before you started, it's not clear to me why one of you would notice and one of you would not. The dashboard should have been vibrating and usually you can feel it in the seat. Driver's seat. The vehicle has a bad resonance right around idle RPM, so 900 maybe worse than what it was at whatever the idle was before. Wasn't there, didn't see it, dunno but that is my suspicion. Might have a tiny vacuum leak but usually the engine gets pretty angry pretty quickly as it messes up the fuel mix. Where does your temperature gauge read on the dash when the vehicle is warmed up?
Click to expand...

She felt the vibrations through her ears (very sensitive and gets car sick in alot of vehicles) I have a truck and been in a bunch of different modifies vehicles so i "felt" a vibration but to me it was a vibration of a 24 year old car. Now after replacing it, the dash does wiggle, she was in it herself one night and said the windshield wiper arm was moving so much you couldnt see the symbols, it definitely didnt do that before the new mounts, is there a better upper mount brand to use? I saw alot of guys in the FB talking about an Amazon mount so i figured the rockauto would be good enough. Its funny though cause before i did notice shutting the car OFF resulted in a pretty bad shake till it stopped, but now when i shut her OFF, its like a new car, but the idle is worse now lol.

The temp when sitting still is usually pinned at half, when im moving on a cool day it will drop probably to like ⅜, or in between ¼ and ½. I just did the water pump and thermostat not to long ago for the recommended stant replacement, and i did a full clean with 7 or 8 gals of water to fully get the dexcool out and replaced with the all general yellow.

2001 sw2 - Bad vibration at idle after new motor mounts

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2001 sw2 - Bad vibration at idle after new motor mounts

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