Rough idle vibration in steering wheel and pulsating noise and vibration

My 97 Riviera sc is idling rough the steering wheel is shaking and I here a pulsating noise . I've already done full tune up and both trans mounts . Could it be an exhaust thing? What do you guys think ? I'm putting a motor mount and two new belts in a few days I only run 93 gas and it only has 73,000 MI it sat for two years . I did oil and supercharger oil and air filter plus other small maintenance.

Any Check Engine Light?

meechie115 wrote:

My 97 Riviera sc is idling rough the steering wheel is shaking and I here a pulsating noise . I've already done full tune up and both trans mounts . Could it be an exhaust thing? What do you guys think ? I'm putting a motor mount and two new belts in a few days I only run 93 gas and it only has 73,000 MI it sat for two years . I did oil and supercharger oil and air filter plus other small maintenance.

What dos "full tune up" mean?

Spark plugs , wires , coil packs , air filter, oil . Haven't done injectors yet but that's not usually included. Spark plugs iridium ac Delco gapped at .60 , blue ngk wires , msd coil packs ( the 5
D576 are sold out everywhere) I have the original coil packs and they are still good by the way . I'll probably get some wires with bigger mm and less resistance probably 8.5 mm msd . But none those should be problem.

Did you use Delco mounts, especially the one in the rear? If you use cheap aftermarket ones they are going to vibrate. I know from personal experience.

Wasn't cheap I don't use anything cheap. I did go store brand on the mounts though duralast . I don't think that's it but obviously idk

That was my problem. The rubber is much harder and translates the vibration through the car.

You remember what brand

West Star or something, got it on RockAuto. As soon as I change to an ACDelco mount it went away. That's why the aftermarket ones are $20 and the AC Delco is like 80

Oh no never go to cheap especially on unknown brands from rock auto . Mine are from AutoZone.... now I'm trying figure out if my clutch is bad or I need flush cus my trans ain't acting right. I'm changing the fluid the filter and gaskets this weekend. Hopefully that'll do it if not I'm changing solenoids and doing a flush . If that don't work the whole thing gets replaced.this what happens when cars sit they fall apart. Still 73000 miles though so imma keep investing

Good luck on your quest.

meechie115 wrote:

Spark plugs , wires , coil packs , air filter, oil . Haven't done injectors yet but that's not usually included. Spark plugs iridium ac Delco gapped at .60 , blue ngk wires , msd coil packs ( the 5
D576 are sold out everywhere) I have the original coil packs and they are still good by the way . I'll probably get some wires with bigger mm and less resistance probably 8.5 mm msd . But none those should be problem.

Check that the primary resistances match each other coil to coil on the ones you pulled - and the secondaries as well.  If they match each other then put the old coils back on. A used D576 is better than a new pretty much anything,inm experience. Two of mine are original to the car and the third was a junkyard coil I got when the new coil I put on to replace one that a bad wire killed off, caused a slight lope.  That's about 410,000 miles of service.

As for wires, the Delco wires for the SC Riv are fine.  

You should check the spec on that sparkplug gap.

meechie115 wrote:

Oh no never go to cheap especially on unknown brands from rock auto . Mine are from AutoZone.... now I'm trying figure out if my clutch is bad or I need flush cus my trans ain't acting right. I'm changing the fluid the filter and gaskets this weekend. Hopefully that'll do it if not I'm changing solenoids and doing a flush . If that don't work the whole thing gets replaced.this what happens when cars sit they fall apart. Still 73000 miles though so imma keep investing

What do you mean by the transmission isn't acting right?

The D576 are nice they are hard to find I still have and my consider but the msd are just as good or the next best thing so should never be a noticeable difference. I can tell you don't understand what the car needs to perform well because you ask me to check but that's the manufactured gap . The old school if it ain't broke don't fix it works but it's narrow. These parts are fine . The wires could be better but they're not bad . I'll see what happens after my last motor mount is changed and belts replaced. My trans fluid needed flush and I did that and replaced filter with gasket also cleaned my solenoid. Should be fine now I didn't receive check engine light but trans was showing different faults but none consistent and from the look of the filter and fluid I say it's good now.

I had a '97 Riviera once. Vibration was up through the steering wheel. Replaced the tranny mounts with replacement Delco's and vibration was gone. Also, remember that the '97 suspension was a one-year-only type. So, you might look into engine mounts too.

meechie115 wrote:

The D576 are nice they are hard to find I still have and my consider but the msd are just as good or the next best thing so should never be a noticeable difference. I can tell you don't understand what the car needs to perform well because you ask me to check but that's the manufactured gap . The old school if it ain't broke don't fix it works but it's narrow. These parts are fine . The wires could be better but they're not bad . I'll see what happens after my last motor mount is changed and belts replaced. My trans fluid needed flush and I did that and replaced filter with gasket also cleaned my solenoid. Should be fine now I didn't receive check engine light but trans was showing different faults but none consistent and from the look of the filter and fluid I say it's good now.

I guess you'll just work on ti until you're done.