Thread: Engine Rattle under load

I just bought an 03 GT. Recently I noticed a rattle in the engine when accelerating. It can't be heard while idling so I'm unsure exactly where it's coming from. It gets noticeably louder shifting into 3rd, but fades at higher speeds. There is also a slight loss of horsepower that comes and goes apparently at random while driving.

Previously, I noticed the engine would pulse when idling, wavering between 600-800rpms. After using a fuel system cleaner idle RPMs rest level at around 900. The rattling faded for about 100 miles but has since returned.

Can anyone tell me the problem and how to fix it? Temperatures have been between 30 and 40f here lately. I'm wondering if that may have something to do with it.

Well, my car stalled for the first time today. Can't say I didn't see it coming. RPMs sit under 800 when idling and surge when cold. When surging it sometimes stutters when RPMs get lower like its going to stall, but I instinctively tap the gas to prevent it.Well, I didn't do that the other day and it stalled three times in a row. It wasn't particularly cold, nor was the engine surging at the time.I recently switched to premium gasoline (91) but have made no other changes. The exhaust leak has yet to be fixed as I decided to get headers and have yet to find a set. I'm aware that's causing problems, but this in particular sounds more like an issue with the fuel system to me. Any suggestions?Also, the engine now makes a whirring sound at higher speeds or when accelerating that sounds similar to a dry leaf against bicycle spokes. There is also some strong vibration before shifting in lower gears. Any idea what this is?

:P I know I tend to post a wall of text, but I'm curious about this raspy whirring sound. Is this normal?

My car occasionally grinds just after starting, as if I held the key in start for too long. It usually tries to stall immediately after. Also, I noticed that when the engine is surging if I turn the steering wheel RPMs go up and then the surging levels itself out for a bit. My lights also dim slightly when the surging RPMs dip low. Surging is not only during idle, just more noticeable. Temperatures have been warmer than when I first noticed this problem, but it actually seems to be getting worse. What should I do?

Thanks, I'm visiting a junkyard next week so that should get taken care of. Also, I drained excess fuel from the engine as per The Manual and it hasn't stalled at start since. My SE had a finicky fuel pump so I had to give it a little gas for it to start. Looks like I'll have to break that habit .