The white smoke from the exhaust is a new development. This wasn't occuring before. Started about 8 months ago and getting worse. Does this info help rule out either bad O rings or head gasket?
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2000 Toyota RAV4 Question: White smoke in exhaust
Answer #1patrick mannion from Greg Solow's Engine Room, January 30, 2010, 11:39Master
On cold start up you will always see "smoke" from the exhaust .On first start up of any car in the morning fuel is not being atomized properly and doesn't burn properly until the engine reaches proper operating temperature. An engine that is burning oil emits blue colored smoke that has an odor of burning oil. It is heavy blue to blue gray in color. If the engine has worn valve guides or valve guide seals oil may drip into the cylinders when the engine is turned off and allowed to cool, then when you start the engine up in the morning you get that trail of smoke out the exhaust. light colored smoke out the exhaust is normal until the engine warms up, especially noticeable on cold mornings dense air. White or sweet smelling smoke out the exhaust perhaps accompanied by rough running would be a sign of a blown head gasket. You will notice grayish colored smoke out the exhaust pipe until the engine warms up. If you are loosing coolant and having to top up the coolant level frequently it may indicate signs of a blown head gasket and needs to be investigated to avoid doing serious engine damage.The most accurate way to test for a blown head gasket on a gasoline engine is to test for the presence of carbon monoxide in the cooling system. Snap-On, Matco (part # CO 2000), and Napa sell a tool to check to carry out this test. Another link to a supplier of this tool is http://www.etoolcart.com/combustion-leak-detector-lis75500.aspx. Carbon Monoxide is only present if there is a blown head gasket or cracked cylinder head. http://www.arrowheadradiator.com/head_gasket_or_combustion_leak_test.htm I think the napa part number 700-1006. http://www.blockchek.com/instructions.htm . Signs of a blown head gasket are coolant loss (frequently have to top up the coolant level of the engine without seeing an obvious leak), experiencing over heating or rough engine running or the presence of white sweet smelling steam from the exhaust. A badly blown head gasket may allow engine coolant and oil to mix.