Detroit D40, D50, D60 Excessive White Smoke


Problem: Injector issues

Problem: Poor Fuel

Problem: Head gasket failure, if white smoke has a sweet smell

Solution: Use one full dose of Diesel Extreme to clean the injectors.

If you suspect poor fuel, treat with Diesel Extreme and change the fuel filter.

Check the head gasket.


White smoke is caused by either unburned fuel or coolant.

If the exhaust smells almost like bug spray, it is unburned fuel. On older trucks, an injection pump that is out of time can make a truck not run as efficiently and blow white smoke. Injector and poor fuel problems can typically be cleared up by treating the truck with Diesel Extreme.

If the exhaust smells slightly sweet, it is coolant. This can be associated with a head gasket failure. This can also cause a mix of coolant and oil.

If you have any questions, feel free to contact one of our diesel experts.

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