Blew up my LT5, Let the grieving begin.

[Torchred96]

Guys, I wish I could be as optimistic on the misfiring injectors, but this noise seems to be much more pronounced, harder, and you can feel it knock. When I first got it and before all the work I did, it had that dual mass knock and misfiring injectors. It scared me until I came here and found out what it was....I'm not so optimistic this time. But, be that as it may, I will at least dig in and find out what happened. I'm just as curious to find out what let go as you are. thanks again


Sam

[LGAFF]

there is someone on the forum that got an awesome deal on a Z with a "rod knock" a coil later and the car was fine

[scottfab]

Gezz sorry this happened. Bummer.
You just have to bite the bullet and start into investigating what it is.
Sooner you know, the sooner you can decide what to do.

[Torchred96]

Lee, I got what I felt was an awesome deal on this car with the same "rod knock" that turned out to be injectors and spark plugs. That went completely away, and the only time I heard noise from then on was a rattle when shutting down the engine...until now.

[Paul Workman]

No expert here, but if you have developed a rod knock, yours would be the first I've heard of in almost 5 years unless it was run out of oil or water or sprayed, or as Lee said, over 8k for some period. And, you would have felt the bottom fall out of the torque well before you hit 8k with the mods you have. I'm thinking (hoping) it is just something else. Happy hunting!

BTW, I'll be seeing Pete and Bob G tonight and Marc in the morning. If they haven't already read about your knocking, I'll ask them about it. I'm leaving to go see Pete soon as I send this!

P.

[Torchred96]

Thanks Paul... It had oil and water and wasn't sprayed. It did run for an unknown amount of time with bad injectors and a miss..not sure it that could have contributed to the problem.

The only thing I've done (the day after it happened) was put a stethoscope on the cam covers..didn't hear anything that I thought was out of the ordinary there..pretty quiet. Then I put it on top of the plenum and I did not like the sound...metallic low pitch sound toward the middle cylinders and diminishing outward towards the front and rear of the engine.

[LGAFF]

Originally Posted by Torchred96

Lee, I got what I felt was an awesome deal on this car with the same "rod knock" that turned out to be injectors and spark plugs. That went completely away, and the only time I heard noise from then on was a rattle when shutting down the engine...until now.

Stuck tensioner can do that too

[Torchred96]

Wait, I did do one other thing...In order to eliminate the accessories as the culprit, I took all the tension from the serpentine belt with a 1/2 ratchet. It looked like all the accessories stopped spinning, but the noise remained.

[PhillipsLT5]

Try this, hope it works

http://www.zr1specialist.com/HAT%20W...in%20Place.pdf

Worst case, time for a 368

[bad-zr1]

One other thing you can try if you have eliminated the accessories is to remove one plug wire at a time. Use insulated pliers and have them loose before hand. It will identify what cylinder is causing the noise if it's in the bottom end. If the noise stays the same I would suspect something besides the rod or piston.
Good luck