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Tom, ASE Certified Technician
Category: Car
Satisfied Customers: 25954
Experience:  ASE Certified Master Technician
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Isuzu Rodeo very loud knocking on isuzu 3.2 OHV v-6 170,000

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very loud knocking on isuzu 3.2 OHV v-6 170,000 miles. Engine and transmission operating well. Noise stops when engine reaches 2,200 rpm. No metal shavings found in oil change. All temps and pressures normal.
Have the intake gaskets been checked?
Customer: replied 6 years ago.
No. But it sounds like metal to metal knocking, or a spun bearing somewhere. The only work done to the engine in the past 6 months was a replaced waterpump. I don't think that its a main bearing though, because it probably would have already chunked a rod. Someone else suggested that it might be a transmission pump/actuator.
Doubt it's transmission related is the noise under the hood top end these intake gaskets are known to crack and cause this issue.
Customer: replied 6 years ago.
Its difficult to narrow down the noise. I initially thought that it was a rocker arm. I'll check the gaskets more closely, but they look ok upon initial inspection. My guess has also been the timing chain. What's your thought on that one?
Honestly if it was the timing belt it would be running very poorly it it is that can be the issue. Most common are those intake gaskets start there spray some carborater cleaner around the plenum of the intake and see if the idle goes up if so those gaskets are cracked . These are the next steps . Hoped this helped.Positive feedback and bonuses greatly appreciated .
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