I get a strange rattle noise from the engine of my 2nd gen when I hit about 70mph. Don't drive on the highway much but when I do this noise is there MOST of the time that I hit 70+. Doesn't seem to be just from rpms. Like I said, only seems to happen when I hit high speeds. Never had the noise until a few months ago. I did a search but didn't think I found anything on this exact situation. If I come off the gas the noise stops after i get below a certain speed /rpm. Any ideas?
thanks
brett

 

thats your truck telling you to slow down. my physics prof. used to tell us that every object has a tune it will dance to. some piece of metal on your rig is dancing to the sound and/or air waves at a certain speed. if its just an annoyance then you're fine, if its loud, duct tape a friend to the hood to try and figure out what is rattling at that speed.

 

yup, resonant frequency.. but usually thats from a sound wave.. i.e your stereo making your trunk rattle, put something on it to make it heavier (dynomat), and change the resonant frequency..

if that is the case, if you go a lil faster it should go away, 2nd gens are notorious for the spedo cable going bad, will give you a rattling noise, in your dash, but you say it's in the engine compartment. really don't know what it could be, pop the hood and see if anything is loose that could flap around.

 

have you checked your driveshaft? maybe it might be abit dented?

 

happend to are vw toureg the drive shaft got hit and was knocked off balance had to have it replaced. created a vibration/ rattle in the car at higher speeds.