: Engine bay rattle, bad vibrations and motor mounts



junoreactor
08-13-11, 02:27 AM
The past few days I'm getting this nasty rattle from the engine bay when under moderate load. It's like a metal rattle/squeaking noise. I can hear it inside the cabin and with the window rolled down, especially when accelerating uphill and letting off the pedal when going down hill. It's possible to apply just a tiny bit of throttle to hit a sweet spot where there is no noise. I've also had a lot of vibrations around 1700-2000 rpms (seems a ton of people have them though).

I've been trying to figure out where the squeaking is coming from but I'm not quite sure. It kind of sounds like the exhaust pipes near the headers/cat connection point are moving a bit under load. However I cannot figure out where the rattle is. When the car is parked and idling there is no rattling, perhaps a bit of exhaust leak but it's minor at this point. Actually sounds like the ticking noise that headers magnify but a bit louder (could be just my imagination). Oh when I rev the engine it makes that crazy rattle whether the clutch pedal is in or out.

So tonight I looked around for quite a while to see what I could guess and just before I was ready to give up for the night I see this bolt on the front part of the driver's motor mount. It's clearly not safe looking and I'll tighten it soon.

http://i765.photobucket.com/albums/xx293/junoreact/2011-08-12231231.jpg
-
http://i765.photobucket.com/albums/xx293/junoreact/2011-08-12231100.jpg

The threads nearest the head of the bolt have an oxidation/dirty color look so it's apparently been backed out for awhile.

My guess is that the engine is moving around too much under load and over time has wiggled and loosened the exhaust joints, etc which could make a metallic squeak every time they bump around. The rattle noise I'm not sure of what is causing that.

Do you guys think that motor mount bolt in the picture could be the cause of my problem of rattling, squeaking, and vibrations? Any thoughts? This is driving me nuts and it's extremely embarrasing driving around sounding like a $500 used car lot beater LOL.

darkman
08-13-11, 10:15 AM
The motor mount bolt could be the problem.

Also, if you still have cats, they can rattle once they have burned out - with the rear O2 sensors turned off you would get no codes.