{"id":2408,"date":"2022-08-11T04:00:50","date_gmt":"2022-08-11T04:00:50","guid":{"rendered":"https:\/\/mycarmakesnoise.com\/?p=2408"},"modified":"2023-01-09T03:15:15","modified_gmt":"2023-01-09T03:15:15","slug":"engine-blow-by-symptoms-causes-and-how-to-fix-it","status":"publish","type":"post","link":"https:\/\/mycarmakesnoise.com\/engine\/engine-blow-by-symptoms-causes-and-how-to-fix-it\/","title":{"rendered":"Engine Blow-by (Symptoms, Causes, and How To Fix It)"},"content":{"rendered":"\n<p>As a car owner, the health of your car engine is always at the top of your priorities. And rightfully so! A car <a href=\"https:\/\/engineering.mit.edu\/engage\/ask-an-engineer\/whats-the-difference-between-a-motor-and-an-engine\/\" target=\"_blank\" rel=\"noreferrer noopener\">engine<\/a> is a complex system of many different parts, all working together to keep your car running.<\/p>\n\n\n\n<p>However, over time and with use, car engines can develop problems. One such problem is <a href=\"https:\/\/www.academia.edu\/29939923\/Title_Excessive_Blow_by_Study_on_high_I.C._Engine_Oil_Consumption_\" target=\"_blank\" rel=\"noreferrer noopener\">engine blow-by<\/a>.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"682\" src=\"https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-Symptoms-Causes-and-How-To-Fix-It-1024x682.jpg\" alt=\"Engine Blow-by\" class=\"wp-image-2409\" srcset=\"https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-Symptoms-Causes-and-How-To-Fix-It-1024x682.jpg 1024w, https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-Symptoms-Causes-and-How-To-Fix-It-300x200.jpg 300w, https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-Symptoms-Causes-and-How-To-Fix-It-768x512.jpg 768w, https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-Symptoms-Causes-and-How-To-Fix-It-1536x1024.jpg 1536w, https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-Symptoms-Causes-and-How-To-Fix-It.jpg 2000w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_71 counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\"><p class=\"ez-toc-title\" style=\"cursor:inherit\">Contents<\/p>\n<\/div><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/mycarmakesnoise.com\/engine\/engine-blow-by-symptoms-causes-and-how-to-fix-it\/#What_Is_Engine_Blow-by\" title=\"What Is Engine Blow-by?\">What Is Engine Blow-by?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/mycarmakesnoise.com\/engine\/engine-blow-by-symptoms-causes-and-how-to-fix-it\/#How_Much_Blow-by_Is_Normal\" title=\"How Much Blow-by Is Normal?\">How Much Blow-by Is Normal?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/mycarmakesnoise.com\/engine\/engine-blow-by-symptoms-causes-and-how-to-fix-it\/#Engine_Blow-by_Symptoms\" title=\"Engine Blow-by Symptoms\">Engine Blow-by Symptoms<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/mycarmakesnoise.com\/engine\/engine-blow-by-symptoms-causes-and-how-to-fix-it\/#What_Causes_Engine_Blow-by\" title=\"What Causes Engine Blow-by?\">What Causes Engine Blow-by?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/mycarmakesnoise.com\/engine\/engine-blow-by-symptoms-causes-and-how-to-fix-it\/#Blow-by_Engine_Treatment_and_Remedies\" title=\"Blow-by Engine Treatment and Remedies\">Blow-by Engine Treatment and Remedies<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/mycarmakesnoise.com\/engine\/engine-blow-by-symptoms-causes-and-how-to-fix-it\/#How_Long_Will_an_Engine_Last_With_Blow-by\" title=\"How Long Will an Engine Last With Blow-by?\">How Long Will an Engine Last With Blow-by?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/mycarmakesnoise.com\/engine\/engine-blow-by-symptoms-causes-and-how-to-fix-it\/#Is_Blow-by_Bad_for_Your_Engine\" title=\"Is Blow-by Bad for Your Engine?\">Is Blow-by Bad for Your Engine?<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Is_Engine_Blow-by\"><\/span><a><\/a>What Is Engine Blow-by?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>Engine blow-by is a condition that occurs when some of the gasses produced during the combustion process escape past the piston&#8217;s rings and into the crankcase.<\/strong><\/p>\n\n\n\n<p>These gasses contain various harmful chemicals, including unburned fuel, water vapor, and acids. Over time, these chemicals can break down the lubricating oil in the crankcase, leading to increased wear on engine parts.<\/p>\n\n\n\n<p>Blow-by also reduces the engine&#8217;s efficiency, as some energy is lost.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_Much_Blow-by_Is_Normal\"><\/span><a><\/a>How Much Blow-by Is Normal?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Regardless of age and other constant factors, all engines have a degree of blow-by. This is because no engine is 100% perfectly sealed.<\/p>\n\n\n\n<p>However, the amount of blow-by that is <a href=\"https:\/\/mycarmakesnoise.com\/transmission\/what-transmission-temperature-is-considered-normal\/\">considered &#8220;normal&#8221;<\/a> will vary depending on the make and model of the vehicle, as well as the owner&#8217;s driving habits.<\/p>\n\n\n\n<p><strong>As a general rule of thumb, though, most engines will have between 5% and 10% blow-by. This translates to 1.5 to 2 cubic feet of air being sucked into the <\/strong><a href=\"https:\/\/www.academia.edu\/29939923\/Title_Excessive_Blow_by_Study_on_high_I.C._Engine_Oil_Consumption_\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>crankcase<\/strong><\/a><strong> every minute under optimum operating temperatures.<\/strong><\/p>\n\n\n\n<p>This figure increases to 3 cubic feet under colder temperatures and during periods of excessive idling. Any blow-by figure higher than 10% is considered excessive and indicative of a problem.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Engine_Blow-by_Symptoms\"><\/span><a><\/a>Engine Blow-by Symptoms<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>A defective engine and especially one with excessive blow-by, will typically exhibit one or more of the following symptoms:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>1.&nbsp;&nbsp; Oil Consumption<\/h3>\n\n\n\n<p>If your oil level drops significantly between oil changes, this is a telltale sign of engine blow-by. But, of course, even for a normal engine, there will be some slight <a href=\"https:\/\/mycarmakesnoise.com\/engine\/how-to-tell-if-your-engine-is-damaged-from-no-oil\/\">engine oil<\/a> drop as service mileage approaches.<\/p>\n\n\n\n<p>However, if you need to top off your <a href=\"https:\/\/mycarmakesnoise.com\/oil\/is-gas-in-oil-normal-causes-and-how-to-fix-it\/\">oil more frequently than normal<\/a>, this is a cause for concern.<\/p>\n\n\n\n<p>Mostly you will notice <a href=\"https:\/\/mycarmakesnoise.com\/emissions\/blue-smoke-from-exhaust-causes-and-how-to-fix-it\/\">blue smoke coming from the exhaust<\/a> pipe. This is because the oil drawn into the combustion chamber is burned along with the fuel.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>2.&nbsp;&nbsp; Loss of Power<\/h3>\n\n\n\n<p>Another symptom of engine blow-by is that you will notice your vehicle is underperforming. This is because, during <a href=\"https:\/\/www.energy.gov\/eere\/vehicles\/articles\/internal-combustion-engine-basics\" target=\"_blank\" rel=\"noreferrer noopener\">internal combustion<\/a>, the air fuel mixture combusts in explosion form, pushing the pistons down.<\/p>\n\n\n\n<p>However, when these gasses escape into the crankcase, they are not available to push the pistons down. This results in a loss of power and can make your vehicle feel sluggish when accelerating.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>3.&nbsp;&nbsp; Excessive Oil Leakages<\/h3>\n\n\n\n<p>If you notice <a href=\"https:\/\/mycarmakesnoise.com\/oil\/why-is-my-car-leaking-oil-causes-and-solutions\/\">oil leaks<\/a> around the seals and gaskets of your engine, this is another symptom of blow-by.<\/p>\n\n\n\n<p>These leaks are usually the result of the increased pressure in the crankcase, which puts strain on the seals.<\/p>\n\n\n\n<p>Under normal operations, the seals can contain the pressure within the crankcase.<\/p>\n\n\n\n<p>In the case of blow-by, the pressure increases, and since the seals are rated for certain pressure levels, they give in, allowing for leakages.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>4.&nbsp;&nbsp; Knocking Sounds<\/h3>\n\n\n\n<p>If you notice your <a href=\"https:\/\/mycarmakesnoise.com\/engine\/engine-knocking-when-accelerating-causes-and-how-to-fix-it\/\">engine making knocking<\/a> or pinging sounds, this is also a symptom of blow-by.<\/p>\n\n\n\n<p>The gasses that escape into the crankcase can build up and cause the engine to run lean. When this happens, the fuel does not burn as efficiently and can cause knocking or pinging sounds.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"682\" src=\"https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-2-1024x682.jpg\" alt=\"Engine Blow-by \" class=\"wp-image-2410\" srcset=\"https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-2-1024x682.jpg 1024w, https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-2-300x200.jpg 300w, https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-2-768x512.jpg 768w, https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-2-1536x1024.jpg 1536w, https:\/\/mycarmakesnoise.com\/wp-content\/uploads\/2022\/06\/Engine-Blow-by-2.jpg 2000w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Causes_Engine_Blow-by\"><\/span><a><\/a>What Causes Engine Blow-by?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>As with any problem in a vehicle, there are several causes of engine blow-by.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>1.&nbsp;&nbsp; Worn Out Rings<\/h3>\n\n\n\n<p>The piston rings in an engine are responsible for sealing the gap between the piston and the cylinder wall.<\/p>\n\n\n\n<p>Over time, these rings can become worn out and no longer seal the gap as effectively.<\/p>\n\n\n\n<p>When this happens, the gasses produced during combustion can escape into the crankcase.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>2.&nbsp;&nbsp; Bad Valve Seals<\/h3>\n\n\n\n<p>Valve seals are responsible for sealing the gap between the valves and the cylinder head.<\/p>\n\n\n\n<p>Over time, these seals can become worn out and no longer seal the gap effectively.<\/p>\n\n\n\n<p>When this happens, the gasses produced during combustion can escape into the crankcase.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>3.&nbsp;&nbsp; Carbon Build Up<\/h3>\n\n\n\n<p>As an engine burns fuel, it produces carbon deposits.<\/p>\n\n\n\n<p>Over time, these deposits can build up and cause the piston rings and valve seals to seize up and function less effectively.<\/p>\n\n\n\n<p>When this happens, the gasses produced during combustion can escape into the crankcase.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>4.&nbsp;&nbsp; Eroded Cylinder Walls<\/h3>\n\n\n\n<p>The cylinder walls in an engine are subject to a lot of wear and tear.<\/p>\n\n\n\n<p>As the engine burns fuel, the piston moves up and down inside the cylinder. Over time, this can cause the cylinder walls to wear away and become eroded.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>5.&nbsp;&nbsp; Ineffective Crankcase Ventilation<\/h3>\n\n\n\n<p>The crankcase in an engine is vented to allow the build-up of pressure to be released.<\/p>\n\n\n\n<p>However, if the ventilation system is not working properly, the pressure can build up and cause the engine to blow by.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Blow-by_Engine_Treatment_and_Remedies\"><\/span><a><\/a>Blow-by Engine Treatment and Remedies<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Now that we know what engine blow-by is and what causes it, let&#8217;s look at some treatments and remedies.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>1.&nbsp;&nbsp; Change Piston Rings<\/h3>\n\n\n\n<p>One of the best ways to treat engine blow-by is to change the piston rings.<\/p>\n\n\n\n<p>This involves taking the engine apart and replacing the piston rings.<\/p>\n\n\n\n<p>This is a fairly difficult job and should only be attempted by someone with experience.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>2.&nbsp;&nbsp; Change Valve Seals<\/h3>\n\n\n\n<p>Another way to treat engine blow-by is to change the valve seals.<\/p>\n\n\n\n<p>This involves taking the cylinder head off and <a href=\"https:\/\/mycarmakesnoise.com\/engine\/how-much-does-an-egr-valve-replacement-cost\/\">replacing the valve<\/a> seals.<\/p>\n\n\n\n<p>This isn&#8217;t as difficult as replacing the rings, but it can be challenging and requires skilled labor.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>3.&nbsp;&nbsp; Change the Crankcase Ventilation Valve<\/h3>\n\n\n\n<p>If the Positive Crankcase Ventilation Valve (PCV) is clogged up, the best way is to change it.<\/p>\n\n\n\n<p>The PCV is responsible for venting the crankcase; if it&#8217;s not working properly, it can cause engine blow-by.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>4.&nbsp;&nbsp; New Engine Block<\/h3>\n\n\n\n<p>In the case of damaged cylinder walls, you might need to get a new engine block, or if you are lucky, engine sleeves will come in handy.<\/p>\n\n\n\n<p>In some cases, <a href=\"https:\/\/www.howmuchisit.org\/reboring-an-engine-cost\/\" target=\"_blank\" rel=\"noreferrer noopener\">reboring<\/a> works but might be costly or ineffective depending on the severity of the damage.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_Long_Will_an_Engine_Last_With_Blow-by\"><\/span><a><\/a>How Long Will an Engine Last With Blow-by?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>There isn&#8217;t a definite answer to this since there are many factors at play here, including:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Driving habits<\/li>\n\n\n\n<li>Mileage<\/li>\n\n\n\n<li>Vehicle age<\/li>\n\n\n\n<li>Operating temperature<\/li>\n\n\n\n<li>Fuel type<\/li>\n<\/ul>\n\n\n\n<p>However, the sooner you undertake the repairs, the better to prevent further engine damage.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Is_Blow-by_Bad_for_Your_Engine\"><\/span><a><\/a>Is Blow-by Bad for Your Engine?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>Yes, engine blow-by is bad for your engine and can cause extensive damage if left untreated.<\/strong><\/p>\n\n\n\n<p>Blow-by puts extra stress on the engine components, leading to wear and tear.<\/p>\n\n\n\n<p>It also causes the engine to run less efficiently and can result in a loss of power. This translates to higher fuel consumption.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>As a car owner, the health of your car engine is always at the top of your priorities. And rightfully so! A car engine is&#8230;<\/p>\n","protected":false},"author":2,"featured_media":2409,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-2408","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-engine","wpcat-8-id"],"_links":{"self":[{"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/posts\/2408"}],"collection":[{"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/comments?post=2408"}],"version-history":[{"count":1,"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/posts\/2408\/revisions"}],"predecessor-version":[{"id":2411,"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/posts\/2408\/revisions\/2411"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/media\/2409"}],"wp:attachment":[{"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/media?parent=2408"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/categories?post=2408"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mycarmakesnoise.com\/wp-json\/wp\/v2\/tags?post=2408"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}