I Think I Screwed Up The Engine

[loudandheard]

Well, I was changing the motor mounts, I had to lift the engine kind of high to take out the mounts. When I lifted it the last time I heard something creak or crack. So i successfully put in the motor mounts and every thing looked good. I start the engine and for the first minute every thing sounds good. After the minute I hear this weird sound, kind of like rattling or kind of like something being forced. That only happens when I rev it at about 1000-2000 rpm. It only happens when I rev it from that range and then smooths out with continued acceleration. I check to see if any thing was loose, but I could not find any thing. There is no check engine light and everyhting seems to be visually sound, but that noise is ver unnerving. I knew I should have left the mechanic work to professionals, but it's so expensive. I fixed one problem and caused another. Does any one know what this could be? Please help!!!!!!

[loudandheard]

I have a video with sound, I just need someone to tell me how to post a link to it.

[NISMOPOWERED]

I would start with the exhaust system. Maybe a leak or something loose on it.

[loudandheard]

Ok I searched the sight, but I still did not find my answer, now I have even more what if's. I think that the noise is coming from the right hand side of the engine compartmnet. I will check the exhaust, but I really think like the sound is coming form the engine compartment. Take in mind that I do not get a check engine light or anything for that matter. I lifted the engine right before the transmission and right after the suspension part and I heard some sort of noise. I am sure that it has to do something with me lifting the engine for the motor mounts. I think it might be the heat shield from reading all the posts, here is a LINK (http://www.club202.com/forums/showthread.php?s=&threadid=812&highlight=sound+engine), but I am not definite. I will have a clip up hopefully tomorrow. At first it revs ok and then about a minute later it makes a hard reving sound at 1000 to 2000 rpm. I really would like some help. I am really worried and even more worried since the engine check light does not come on. I just want to know what the problem is. I never had a problem before this and need to resolve thsi problem.

[mayagman]

My friend was installing a CAI on his 3000GT one day.. Simple operation, but we experienced the same thing. He had dropped a washer down the intake plenum and it somehow made it past the valvetrain and into the cylinder. The rattling sound was the piston pounding the washer into the head on each stroke. Not saying that's your problem, but a good place to start is to make sure all your nuts, screws, bolts and washsers were accounted for during the operation.

As far as technical advice for your problem, there really isn't any, unless someone can think of a common mishap that occurs during this procedure. I cannot think of any, but problems like this are on a case-by-case basis... Tie a magnet on to a string and start feeling around down there. You'll be shocked what you find.

[jnenad16]

did you unhook the ground strap between the trans bell housing and the frame? if not, it could have snapped and the result could be a poor grounding, meaning the electrical systems may not function properly, such as the ingition, which may misfire/hesitate. make sure you check that. other than that, I really cant help you much unless I inspect the car myself, so if you cant find the cause to your problem, take it to a shop and tell them, in detail(very important!), what you did before this happened.

nenad

[loudandheard]

I was talking to a friend of mine and he said it could either be a stuck cylinder or the timing chain. The sound seems to be coming from the engine itself and not the parts around it. I know what to do to get the cylinder unstuck, but how do I go about checking and maybe even replacing the timing chain?

[jnenad16]

take off the valve cover and inspect the chain and the tensioner.

nenad