2004 Pontiac Grand Prix. Vehicle had a 50:50
mix of Diesel Gas put into it when it already had
some gas in the tank.
The car ran approximately 18km when it lost
power and started making noises.
All spark plugs had been smashed and had bits
of melted aluminum on the porcelain. Crown on
one piston was broke off. Piston rings damaged.
This vehicle did not have any previous problems
until this fuel was put in. The mechanic that
looked at the car said that bad fuel would not
cause engine damage. That the damage had to
be caused by something else. Would diesel
mixed in the gas and ran through the system
cause severe engine damage. What kind of
damage could that be? What do we look for?
Thank you for the tip/donation.The answer is YES.
A diesel/gas mix can cause this engine damage. Diesel and gas
obviously have very different properties. They burn in a completely
While driving, the unburned fuel in the cylinders was probably
pooling up in the cylinders. A gas engine cannot run on liquid
fuel. A cylinder that begins to fill with liquid will cause that
cylinders pressure to go sky high since there is less area for air,
the cylinder walls will have the oil washed off. The cylinders will be
very unbalanced as it is running.
The shear compression of a liquid will cause spark plug and
piston damage. Flakes of material on all spark plugs is because
the piston(s) were starting to come apart, and metal was being
transferred throughout the engine. The computer was trying to
compensate for the strange readings on the oxygen sensors,
injector pulse would be changed, timing would be changed, and
the engine would go into an unstoppable failure.
With such an difference in cylinder pressures, the timing chain
may have jumped/broke, and caused the pistons to hit all the
plugs. Although as stated above, the extreme pressures in the
cylinders is enough to do that, and to break a piston.
While driving this way, there were VERY violent things happening
in the cylinders. Cylinder temperatures would be different from
cylinder to cylinder, etc. The engine should be replaced, all the
injectors replaced, fuel pump replaced, fuel tank, lines, fuel rail
cleaned out, fuel filter replaced, oxygen sensors replaced,
catalytic converter checked for damage.
If you need any more help, just let me know. Thanks again for
Diesel Fuel In Gasoline Causes Engine Damage