Harmonic Balancer

[SL2_Gold]

Did saturn install harmonic balancer on the 1995 Sl2 model. Ive found harmonic balancers for SL2 96 to 02 but I cant find any for the 95 model. I want to know because I have a loud vibrating noise coming from the cabin at idle but Ive checked the motor mounts and there fine. So Im guessing its the harmonic balancer failing but I need to know if there is even a harmonic balancer to fail in my car. Thanks.

[ssicarman]

As far as I know all of the DOHC engines got a balancer. The SOHC engines only got pullies. Have a look at the balancer and see if the outer/inner portions have come loose from the rubber and is causing vibration.

[tarsun]

i dont have one. or atlast i think i dont...
i put a set of underdrive pulleys on. my crank pulley is almost nothing

[virnin]

Originally Posted by SL2_Gold

Did saturn install harmonic balancer on the 1995 Sl2 model. Ive found harmonic balancers for SL2 96 to 02 but I cant find any for the 95 model. I want to know because I have a loud vibrating noise coming from the cabin at idle but Ive checked the motor mounts and there fine. So Im guessing its the harmonic balancer failing but I need to know if there is even a harmonic balancer to fail in my car. Thanks.

Yes, all Saturn 1.9L DOHC have one and I think it's the exact same part# from '91 to the end. However, given the construction, you should be seeing significant damage to the serpentine belt since the harmonic balancer is also the crank drive pulley. If it's deteriorated to the point of causing vibration, the outer ring that drives the belt should be flopping all over the place. Plus, it would not get better at speed than at idle.

I'd keep looking before the problem before replacing the harmonic balancer. You checked all FOUR components of the mount system?

Have you tried loosening then retorqueing the frame bracket for the "dog bone" strut under the front of the engine?

If somebody replaced the top engine mount and didn't finish the job by allowing the power module to settle into its "home" position using the above procedure than you could get vibration due to one or both torque struts being pre-stressed.

[BarnOwl]

Originally Posted by ssicarman

As far as I know all of the DOHC engines got a balancer. The SOHC engines only got pullies. Have a look at the balancer and see if the outer/inner portions have come loose from the rubber and is causing vibration.

Okay, somebody straighten me out. AFAIK all Saturn engines are internally ballanced. So, there's not really a harmonic balancer. The DOHC pulleys do have an outer an inner portion separated by rubber and the SOHC pulleys are one piece. I believe I've seen a post from Low Saturn where he said he used an SOHC pulley on a DOHC with no noticeable effects.

[froggy81500]

i could check my haynes manual at home from my wife's old s series and see if they mention it

I'd be suprised though, I haven't seen too many motors that were internally balanced, unless I just wasn't aware some were

[Gerry Proctor]

Depends on how you're applying the term. A damper (harmonic) dampens crankshaft harmonics. These are usually not severe enough in low horsepower cars to be noticeable (since the harmonic is caused by the force of the piston accelerating the crankshaft causing pulses. The engine may be idling at 600 rpm, but the crank is speeding up and slowing down at each ignition event. This "rocking" or pulsing is absorbed by the damper. The hub is fixed to the crankshaft and is separated by an inertia ring attached to the hub by an elastomeric ring. The outer hub lags on the firing pulse and rebounds or returns the energy on the deceleration part of the pulse. This inertia ring is what dampens the pulses that cause the harmonic in the crankshaft. The harmonic sets up a vibration in the engine.) and many such engines use only a crankshaft hub without a damper. A damper that has an imbalance weight (harmonic damper/balancer) is used as an external weight to help balance the crankshaft. It doesn't matter whether the engine uses a damper or a solid hub. Either can be a balancer as well. And many externally balanced engines use an offset weight on the flywheel or on both the flywheel and damper (hub). Of course, an internally balanced engine doesn't use weight offsets on either end of the crank.

[froggy81500]

horsepower doesn't really have to do with it as does rpm's. You've got a rotating mass attached to the crankshaft and at higher rpm's can become very unstable. You start spinning around that kind of weight too fast and bad things can happen. Just as much as a balancer or damper smooth things out at idle, it really matters when you're putting a foot in it.

BTW, the online manual for the s series on autozone mentions a damper pulley

[Gerry Proctor]

First order harmonics are a function of the power pulses and the more "push" there is on the piston, the more significant those tend to be. Those that are harmonics in second, and third orders are related to rpm but are amplifications of first order harmonics. Fourth order harmonics are fundamentally related to rpm.

[madpogue]

Gold, how exactly did you check the motor mounts? Can you fit a pen/pencil between the rubber block and the steel top bracket on the top engine mount? If so, put a fork in it, it's done.

[SL2_Gold]

Umm ya I checked it today and ya i can fit my finger through it so Im going to go ahead and replace it and see if that does anything. Ill let you guys know what goes down.