Hello forum members! I currently looked through finding what might be wrong with my 300zx and I was referred to your forum. I searched your forum but might have missed some posts/didn't put in correct "keywords". Miles: 93k Transmission: Auto Problem - The engine is making weird noise. Things that have been done: Put in Lucas Heavy Duty Oil Stabilizer - The sound went away it seemed but it came back in moments. Changed the oil - Same problem - Did not see any major metal shaving/large quantity Changed the spark plugs - No change in the sound Checked the Compression - Looks good I have heard different things that could be wrong with the engine but no one is certain. Someone said it could be the timing belt that is making that noise or the exhaust. I looked at the Tech manual for the car and most of the noise is coming around the right side of the engine mainly by I guess the Exhaust camshaft. Here are two videos. One seems to have an annoying sound (wind blowing by sound) that Youtube formatted my video to (it is not the car). Links: http://www.youtube.com/watch?v=MT2E7lRzhcs http://www.youtube.com/watch?v=7_xD8R3uv9E Thanks for any help possible. I will try to answer any questions that come up! (I am not car savvy).
Thanks for the suggestions! Since I am starting from outside taking it apart, we took the right side timing belt cover and we can greatly hear the noise. The noise we suspect is actually from the middle bearing or pulley (I do not know the terms) and the belt didn't seem tense and while running it (you can see it fluctuate) and after we stopped it (end of the video), it tightened, but it still seemed flexible. Here is what I mean (the video), but the timing seems off also? http://www.youtube.com/watch?v=roP3kpPD9v0
I'm with K-zed on what area is making the noise - ie the cams. It could be a broken spring in the variable valve timing of the inlet cam. I went chasing a similar noise in a Zed a few years ago. The owner thought it was a big end problem (sounded awful!), but using ConZult, you can force the variable valve timing solenoid on at idle. I did this, and hey presto - the noise disappeared immediately! He was very relieved that it didn't mean an engine rebuild Can I suggest that you find someone with a ConZult. plug it in, idle the engine, go to the solenoids test and click the "valve timing - solenoids" box. This forces the VVT solenoid on at idle. It usually doesn't come on until higher revs, at which point the engine noise masks the fact that the noise has disappeared. If the noise disappears when you do this test, you've probably got a cam gear or variable valve timing control solenoid valve problem. Hope that helps
