Rough idle/ shuddering in idle.

[iboughtatahoe23]

RPMs seems steady, some hairline movement/bouncing but I think that might be normal. I’m having a rough idle or like a shutter every 4 seconds in park it seems like. When I put it in drive it will drop down to 500 rpm and it goes away.

I have done maf sensor, throttle body cleaning, and serpentine belt and idler pulley. Was gonna do plugs. Air filter is good too. What else can I do?

 

[iboughtatahoe23]

I have other threads about potential transmission and exhaust leak issues, but I don’t think either of those can contribute to a Rough idle.

 

[iamdub]

Depending on what you mean by a "shudder", I'd say it could be an indication of a problem. Otherwise, it sounds like normal operation for these things.

 

[OR VietVet]

How old are the plugs and wires? Any CEL?

 

[iboughtatahoe23]

How old are the plugs and wires? Any CEL?

Haven’t been changed since I had the vehicle. So pretty old I assume!

 

[iboughtatahoe23]

At

Haven’t been changed since I had the vehicle. So pretty old I assume!

167k miles

 

[iboughtatahoe23]

Depending on what you mean by a "shudder", I'd say it could be an indication of a problem. Otherwise, it sounds like normal operation for these things.

It’s just when I’m in park idling. A shutter or shake i feel every couple seconds or more

 

[ivin74]

It’s just when I’m in park idling. A shutter or shake i feel every couple seconds or more

I would start with changing out plugs and wires.

 

[Marky Dissod]

I would start with changing out plugs and wires.

Although I heartily agree with this recommendation, I would ALSO:
check ground wires for solid connections
check alternator & battery with stress / load tests (preferably with every single accessory on all at once)
check fuel pressures at idle, & 2nd gear start if you have that feature enabled
check PCV Valve or orifice-thingy

 

[iamdub]

It’s just when I’m in park idling. A shutter or shake i feel every couple seconds or more

Right. It's probably the norm for these things, so don't get too concerned if there are no other ailments- No DTCs, no funky operation, MPG is where it should be, etc. But, as the others mentioned, you're overdue for some basic maintenance and inspections. A wise (or wise ass?) old man once said "maintenance pays, breakdowns cost". Plugs, wires, induction and PCV cleaning, check fuel pressures, oils/fluids, coolant, rubber parts, charging system and grounds, etc. Don't get the suspiciously cheap spark plugs from Amazon or eBay as they're highly likely to be counterfeits that could wreck your engine.