Vibration when stopped in gear...

[96Firebird]

My girlfriend recently got a 1999 Saturn SC2 to replace her Blazer for better gas mileage. The car has 86,000 miles on it, which I thought was a decent deal for the $3000 she paid for it (especially considering the outrageous prices of used cars at the moment). There are no problems with the car, everything works.

The only "issue" with the car is that it seems to vibrate while in gear and not moving. So, say, sitting at a red light or stop sign. It is almost like the engine is idling at a resonant frequency that will vibrate everything inside the car. However, once the gas is pressed, the vibration and loud noise goes away. The exhaust is a little loud, but nothing horrible. I am thinking it is either motor mounts, or the idle speed needs to be adjusted. Could it also be the exhaust manifold at a certain frequency?

I know it is not a misfire, I've felt this in both my past and current car from bad coil packs. Any ideas as to what it might be, and any ways to further diagnose the issue?

Thanks in advance.

 

[exdeath]

Motor mounts. When stopped in gear, in an automatic, the engine is pushing against the torque converter and bouncing against the mounts and vibrating. Since the car won't move, the engine has to. When moving forward, the torque converter is moving and the engine is pinned steady against the direction it's wanting to rotate and doesn't bounce around, unless there is a sudden throttle change. Putting it in neutral should also quiet it down quite a bit since the engine is free to rotate without anything to push against.

You can drive around in 1-2 and upshift and downshift while on the throttle and you will feel a heavy buck or clunk to confirm mounts.

 

[Bartman39]

^ditto...

 

[96Firebird]

Thanks guys, I'll take a look at the upper mount tonight when she gets home to see if I can see any noticeable problems. The lower one will have to wait until I can get under it with a jack...

 

[96Firebird]

I had my girlfriend start the car and put it in gear while I was watching the motor and there seems to be plenty of movement in the motor. However, the upper motor mount isn't the OEM one, so it has been changed before. After doing some reading, it seems the replacement parts (non-OEM) are crap and will need to be replaced often, which is what is in there right now. Does anyone know where I can get an OEM upper motor mount for this car? I tried GM parts direct, but they don't have Saturn listed anymore. I have found a few places, but they don't show any pictures of what the item is and they list for ~$80. I can get the cheap non-OEM from Rock Auto for $20 shipped. Any other options for OEM parts? Is it a bad idea to get a junkyard motor mount?

 

[iamwiz82]

I wouldn't do a JY part for something that is a wear item. Rock doesn't have OEM mount available as well?

 

[96Firebird]

No, they only have the Anchor part, which is what is on there now and what is not recommended. Maybe they just don't make the OEM anymore...

 

[JCH13]

You may want to consider after market racing/performance mounts. There will probably be more light vibrations transmitted, but they're generally more rugged than even OEM mounts, in my experience anyway.

 

[GasX]

You may want to consider after market racing/performance mounts. There will probably be more light vibrations transmitted, but they're generally more rugged than even OEM mounts, in my experience anyway.

googling "Saturn race cars" probably doesn't get many hits...

 

[CrackRabbit]

googling "Saturn race cars" probably doesn't get many hits...

lawls.

Seriously though, urethane mounts are much more durable than their rubber counterparts, though they do tend to transmit a bit more vibration.

Unless Saturn used hydraulic mounts like Ford did.

 

[CrackRabbit]

dp

 

[JCH13]

googling "Saturn race cars" probably doesn't get many hits...

Lol. ~2.6M Google hits FTR. :awe:

Mount insert kit:
http://www.summitracing.com/parts/PTP-7-510
May require a press/bench vise for installation.

Totally new engine mounts here:
http://streetdesignauto.net/

Quick forum searching suggests that the pre-installed guys are worth every penny if you don't have a press, but that a bench vise can eek you by.

 

[Viperoni]

SDA makes good stuff, I had their dogbones in all my saturns.

Generally only the upper motor mount ("TAM") goes on turds, generally, and the aftermarket (Anchor, etc) are good enough - not worth spending the money on Saturn OEM parts.
The StreetDesignAuto TAM might be a bit rough, it will transmit a lot more vibration than a regular rubber mount, but will not allow the engine to move as much.

Frankly I'd just get the aftermarket mount if it's anything more than $20 cheaper than the Saturn or SDA mounts.

 

[HarryLui]

Mount insert kit:
http://www.summitracing.com/parts/PTP-7-510
May require a press/bench vise for installation.

Totally new engine mounts here:
http://streetdesignauto.net/

Both are bad idea, if you want to reduce vibration.


http://www.saturnfans.com/forums/showpost.php?p=1793779&postcount=4

 

[JCH13]

Both are bad idea, if you want to reduce vibration.


http://www.saturnfans.com/forums/showpost.php?p=1793779&postcount=4

As I mentioned in an earlier post, they will transmit light vibrations.

 

[96Firebird]

We went cheap and just ordered the $20 Westar mount from Amazon. If we need to replace it next year, so be it. It is easy to replace, and as long as some of the vibration goes away she'll be happy...

 

[kornphlake]

Motor mounts are a known weakness in saturns. I've been using mounts from AutoZone with a lifetime warranty, I think I'm on the 3rd or 4th lower "dogbone" mount and my 3rd top engine mount, I only had to pay once... The mounts are pretty quick and easy to change and last about 2 years before needing to be replaced.