Had to drive about 20 miles in a snowy mess yesterday, was going around 45mph or so. Threw it in 4, (07 tacoma, 5sd. 2.7 reg cab) and the whole time i was in 4wd the engine sounded a bit louder. Should it be louder? It drove fine, only has 10k on it. When 4 was off sounded normal. It wasn't absurdly loud, just a bit more than normal
i really think it may be the engine under more load. it didn't sound "bad" just louder. No radio or talking and i could hear it, the slightest yapping or radio etc and i wouldn't have heard it.
I'm probably just paranoid. i've owned so many beater jeeps and junkers that i freak and investigate all noises and still look under this 10k miles only tacoma for drips.
I thought I may have had some problems when I first put it into 4wd when we got a big snow, but I kind of filed it away as a normal sound. Maybe not? It wasn't too bad but definitely noticeable.
I dont remember there being noise in 4wd when new, there's no sound difference between 2wd & 4hi for me or other Tacomas I've been in. Sure you weren't in 4lo? at higher speeds there is a slight gear whine.
do you have a 4 cylinder? it drives fine and it's not ridiculously loud, just noticable. Then again I've owned several jeeps, so i'm accustomed to listening for all kinds of s hit.
i guess i'm not going to sweat it....the regular cab 4x is loud as hell anyway, makes since if it's working harder, besides i'm fairly proactive w/ maint, oil changes etc and climb around alot under it, taking notice of things. Runs great. I'll ride this out.
I have not noticed an increase in noise while driving, just the need for a little more throttle than otherwise would be necessary.
I have noticed that at 30 MPH when accelerating slowly, and when slowing (no brakes) down I get a harmonic noise while 4 wheel drive is engaged. It only happens from 30 - 32 MPH, and only with 4 wheel drive engaged. It's a subdued sound, but I can hear it when the music is off. Not sure if that sound is normal, but I haven't had any issues in the 10K that's on it.