{"id":12558,"date":"2020-01-30T16:55:29","date_gmt":"2020-01-30T21:55:29","guid":{"rendered":"https:\/\/techlink.mynetworkcontent.com\/?p=12558"},"modified":"2020-02-03T14:26:05","modified_gmt":"2020-02-03T19:26:05","slug":"v8-engine-vibration-condition-at-1200-rpm","status":"publish","type":"post","link":"https:\/\/gm-techlink.com\/?p=12558","title":{"rendered":"V8 Engine Vibration Condition at 1,200 RPM"},"content":{"rendered":"<p>Some 2019-2020 Silverado 1500 and Sierra 1500 models equipped with the 5.3L or 6.2L V8 engine (RPOs L82, L84, L87) may have a vibration or drone sound around 40 mph (64 km\/h) and 1,200 rpm under a light load. Around 1,200 rpm when Dynamic Fuel Management\/Active Fuel Management (DFM\/AFM) is operating, the condition may seem to get worse after the engine has reached operating temperature.<\/p>\n<p>If the vehicle was maintaining speed, engine speed and engine load while in DFM\/AFM mode, the tone of the vibration can shift noticeably and amplitude may decrease slightly as different cylinders are deactivated.<\/p>\n<p>A review of the CH-51450 PicoScope automotive oscilloscope files recorded during the condition may indicate:<\/p>\n<ul>\n<li>When vibration was first occurring, there may be a large spike that aligned with E1 (Fig. 6, #1) and E2. (Fig. 6, #2)<\/li>\n<li>After the tone shift, the vibration is no longer directly aligned with E1 (Fig. 7, #3) and E2. (Fig. 7, #4)<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-12528\" src=\"https:\/\/techlink.mynetworkcontent.com\/wp-content\/uploads\/2020\/01\/F06-vibe-1.png\" alt=\"\" width=\"740\" height=\"480\" srcset=\"https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F06-vibe-1.png 740w, https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F06-vibe-1-300x195.png 300w, https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F06-vibe-1-85x55.png 85w, https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F06-vibe-1-200x130.png 200w\" sizes=\"auto, (max-width: 740px) 100vw, 740px\" \/><strong>Fig. 6<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-12529\" src=\"https:\/\/techlink.mynetworkcontent.com\/wp-content\/uploads\/2020\/01\/F07-vibe-2.png\" alt=\"\" width=\"740\" height=\"480\" srcset=\"https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F07-vibe-2.png 740w, https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F07-vibe-2-300x195.png 300w, https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F07-vibe-2-85x55.png 85w, https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F07-vibe-2-200x130.png 200w\" sizes=\"auto, (max-width: 740px) 100vw, 740px\" \/><strong>Fig. 7<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>If this vibration is found, remove and inspect the transmission mount for any debris. (Fig. 8) Clean the mount, reinstall, and evaluate the vibration condition.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-12530\" src=\"https:\/\/techlink.mynetworkcontent.com\/wp-content\/uploads\/2020\/01\/F08-vibe-3.png\" alt=\"\" width=\"740\" height=\"480\" srcset=\"https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F08-vibe-3.png 740w, https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F08-vibe-3-300x195.png 300w, https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F08-vibe-3-85x55.png 85w, https:\/\/gm-techlink.com\/wp-content\/uploads\/2020\/01\/F08-vibe-3-200x130.png 200w\" sizes=\"auto, (max-width: 740px) 100vw, 740px\" \/><strong>Fig. 8<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><em>&#8211; Thanks to Richard Renshaw<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Some 2019-2020 Silverado 1500 and Sierra 1500 models equipped with the 5.3L or 6.2L V8 engine (RPOs L82, L84, L87) may have a vibration or drone sound around 40 mph [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-12558","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/gm-techlink.com\/index.php?rest_route=\/wp\/v2\/posts\/12558","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gm-techlink.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gm-techlink.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gm-techlink.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gm-techlink.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=12558"}],"version-history":[{"count":3,"href":"https:\/\/gm-techlink.com\/index.php?rest_route=\/wp\/v2\/posts\/12558\/revisions"}],"predecessor-version":[{"id":12571,"href":"https:\/\/gm-techlink.com\/index.php?rest_route=\/wp\/v2\/posts\/12558\/revisions\/12571"}],"wp:attachment":[{"href":"https:\/\/gm-techlink.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12558"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gm-techlink.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12558"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gm-techlink.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12558"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}