1984 Jeep Cherokee engine knocks

1984 JEEP CHEROKEE
16,000 MILES • 6 CYL • 4WD • MANUAL
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BULLDOG102DS
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i have a 1984 jeep Cherokee and lately the engine has been knocking i know it is the wrist pin in one of the pistons but i don't know which piston it is, how do i isolate which piston the knock is coming from.
Oct 28, 2008 at 7:16 PM
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MHPAUTOS
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Hi there,

you will have to isolate the cylinder, if fuel injected just un plug the injectors one at a time, you may here a change in the knock as there is less pressure on the piston with that cylinder dead, don't try removing the plug lead as you will get a shock, and with the extra fuel in the cylinder when you hook up again you could blow out a muffler, if carby this test can be done on an oscilloscope, but a qualified mechanic will need to hear this as the change in noise will be slight, start here.

mark (mhpautos)
Oct 28, 2008 at 8:31 PM