Chains or tensioners?Was this issue ever diagnosed? I have an '01 Cobra with 4v 4.6 and also have a momentary "rattle" at cold start, but it happens during every cold start not just sitting for a few days. My car has ~70k miles and I plan to auto-cross race it more regularly next year and want to make sure I don't need to replace bearings before I start. Right now I daily drive it without any knocking/rattling sounds after cold start.
Excuse my not-knowing, but is this something to be concerned about or something (to learn) to live with? I just want to know what kind of additional maintenance I need to do to get the car ready.Seems like most cold start rattles are from chain tensioners not fully pressurized because of negative travel.
I can definitely hear the noise from the drivers seat during startup. I could have my wife start the car when it's cold while I stand on the side with the hood open and listen right from the middle of the motor to see which end the sound is coming from. Seems it could be one of multiple issues.Timing chains rattle is very prominent at the front of the engine. The thrust bearing is most noticeable from inside the car as it's usually the rear bearing at crank/ block mating.
i have a noise when i cold start as well...5 speed 5.0 vert...only on cold starts with the clutch all the way in..half out or in just enough to start and its minimal and goes right away...ill post a video tonightWell if you get close to redline and that same rattle, it's definitely a thrust bearing.