FWP!

I'm worried about my fairly new '00 Mustang. I've only had it 3 weeks, but I noticed a few days after I bought it that it has an oil feed and an oil return port on the engine. Which means to me that the engine was blown before I bought it.

At around 4000 RPM I swear I can hear a little bit of a clacking sound like rod knock. I'm almost positive it is. The engine's been ****ed with, pretty sure it's been taken out, a ground strap is cut, new heads are on, the oil dip stick tube isn't bolted down to the head at all. Maybe I should get a recording of the noise or do you guys think a mechanic would be able to tell me whether or not the noise is normal. It's not horrible but if you listen you can hear it. I'm new to Mustangs and I'm not sure if it's typical of a 4.6. I read about piston slap somewhere else, this could be it, I dunno. It makes no noise in the lower revs, really only does it once I get above 3800+ rpm.

I have a feeling it's not good news...

FWP!

Nothin huh?

PipsBlackStang

Well how bad is the knock? If its that bad than I suggest bringing it somewhere to get it checked out because it could turn deadly. Or take it apart yourself and save some cash if you got the tools.

FWP!

Well, it's noticeable. But I don't want to rip into the engine if it's something like detonation.

Would my ECU still being on a forced induction setting from the previous owner (the car is now n/a) effect anything as far as detonation or anything like that?

Dan04COBRA

Have you taken a screw driver or maybe a steth to the valve covers to see if the noise is coming from the top end or bottom end?

Bottom end noises tend to have more of a thunk, you tend to feel them, when you have a tick or a tap you just hear it and don't feel anything.

A blower tune in a N/A would really cause you to run extremely rich, I don't see why it would make you knock.

FWP!

That's what I thought, about the running rich thing. It was just a suggestion from someone on another board.

When the car is idling, it's dead quiet. I don't have my digital camera with me today at work otherwise after work I'd go out and take a quick vid, the camera picks up sound really good so it'd help I think. But I won't be where the camera is till tomorrow probably so I'll do it then. I should be able to just open the hood and rev the engine to get you guys to hear what I'm talking about. Although, I think you might be able to hear it better from inside the cabin with the windows up because the body of the car keeps out the noise of the exhaust and other lower toned noises and it lets you hear higher pitches noises like what i'm hearing.

Eh... I'll get a recording soon. Sorry for rambling. It just bothers me, this is my new "baby" and I'm worried about it I'm not going to feel comfortable driving it until I know for sure what the problem is.