These are some good things to go after. A compression test could tell me alot. Especially if I have a stuck lifter. I also plan on shooting the motor with a temperature gun while idling to check for any temperature issues.
2017 Tahoe with very rough idle
- Thread starter dksharp
- Start date
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vcode
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Does the vibration go away if you increase rpm's at idle by 100-150? A lot of these trucks have a rough idle from GM setting the idle speed so low.
Probably not your issue if it just started.....
Probably not your issue if it just started.....
houstontaylor
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I did have vacuum leaks on my 2003 Tahoe with 355,000 miles causing a rough idle. The latest incident turned out to be an old loose vacuum hose from the brake booster that looked okay at first glance. However, when I pulled on the hose I could see that the connection at the engine was loose, so I replaced the hose and replaced the clamp at the engine with a stronger one for the new thicker hose. I have done the same test on the air intake duct another time and found the connection to be loose and leaking air where it attaches to the throttle body. And I did also at one time replace the pcv hose that was worn and loose at the valve cover.
Resolved- We had a mobile mechanic come out and he hooked up the live data monitoring and found the fuel values to be around -30. He started checking the air system since this truck was running rich. He found a small amount of plastic melted on the MAS air sensor and he scaped it off and it began running better. We ended up replacing this with a new one for 100 dollars. He also did the idle relearn procedure. The motor mounts he said were ok. So the car is currently running and idling well. Thank you all for the good advice.
