knocking sound from the new replaced engine


Asked by Sep 08, 2015 at 03:39 PM about the 1991 Nissan 300ZX 2 Dr STD Hatchback

Question type: Maintenance & Repair

I just replaced the engine in my 91 Nissan 300zx. When I started the car it mad
a loud noise. Sounds like a machine gun going off. What is wrong with the
engine. By the way the engine is aJDM.

4 Answers

Kelly Mayo

could be anything>>>even a belt.


you may need to tighten your exuast headers?


carbon is in the combustion chamber, the engine was having its first life, then it sat. the carbon deposits dried, flaked, etc. You start it again in a different car, after sitting and you hear the dislodged deposits. Combustion chamber cleaner, an exhaust management shop system for the smoke and voila. This is normally diagnosed by the engine installer or builder if the heads stayed on and chambers were not cleaned prior to install. The operation is best performed professionally.

Bob Beaman

Did you put oil in it?

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