Abnormal noise after rebuild. Movie clip included.

[half-cocked]

Engine has about 5 minutes tops on it total, was rebuilt 20 over with Ross pistons and the piston-bore clearance is a hair excessive because the machinist cant follow directions, other than that its stock. Since the second I fired it up it made this noise. I am going to rule out rod knock due to it was there right out of the gate, its always there (my last engine spun a bearing and it only made the knocking noise off throttle) and its very uniformed RPM related. I thought it was lifter tick but it seems too low in the engine, but that still may be the case, the are not revised lifters. It could be piston slap, I have not totally warmed up the engine to see if it quieted down, but thats my next step after I button up a few things. It seems to be coming from really low behind the timing belt cover, no damage or wear on the belt though.

This clip sounds like exactly what it sounds like while I am sitting IN the car. When I stick my head in the engine bay it almost sounds like somethings rubbing. Odd thing is the car ate a alternator belt right off the bat, I put a new one on and it is fine, could it be the crank pulley?

Movie clip:

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[97ClipseDSM]

Doesnt sound like a rod knock but you might want to check your balance shaft belt if you havnt already eliminated it.

 

[half-cocked]

Doesnt sound like a rod knock but you might want to check your balance shaft belt if you havnt already eliminated it.

Sorry, forgot to add that the balance shafts are eliminated.

 

[andymoraitis]

Make sure the auto tensioner hasn't lost it's tension and taken a crap on you since it can make a similar sound to this. It would also be a great idea to ensure that your timing marks all line up properly.

Also, with the motor making the noise, pull and replace each spark plug successively. If the noise goes away, it usually indicates rod knock, but rod knock usually starts at 2500 RPM and above and sounds a bit different.

A third option is to remove your plugs and your valve cover. Rotate the cams from the main crank pulley (easier with the spark plugs out) until the lobes are not resting on the rocker arms. If you can push down a lifter with pressure from your finger, it's collapsed and needs to be replaced.

If all of those turn out to be moot, replace the plugs and wires and check the coils. It almost sounds like you're on 3 cylinders, but it's hard for me to tell.

Sounds are tough, but hopefully that's enough to get you started.

Good luck,

Andy

 

[97ClipseDSM]

Something sounds loose thats for sure. I would check the crank pulley, as that can create all sorts of hell sounding noises. It almost sounds like something rubbing on something. The above ^^^^ post would be a great place to start.

 

[half-cocked]

Make sure the auto tensioner hasn't lost it's tension and taken a crap on you since it can make a similar sound to this. It would also be a great idea to ensure that your timing marks all line up properly.

Also, with the motor making the noise, pull and replace each spark plug successively. If the noise goes away, it usually indicates rod knock, but rod knock usually starts at 2500 RPM and above and sounds a bit different.

A third option is to remove your plugs and your valve cover. Rotate the cams from the main crank pulley (easier with the spark plugs out) until the lobes are not resting on the rocker arms. If you can push down a lifter with pressure from your finger, it's collapsed and needs to be replaced.

If all of those turn out to be moot, replace the plugs and wires and check the coils. It almost sounds like you're on 3 cylinders, but it's hard for me to tell.

Sounds are tough, but hopefully that's enough to get you started.

Good luck,

Andy

Thanks, I'm just going to run down this list and see what helps. I have a good idea that it is the auto tensioner now. Because when I was building the bottom end about 1.5 years ago I was broke as a joke and reused the old one, I know bad move.