bpealer

My engine has been a bit noisy, but yesterday I've noticed this odd knock/tapping sound that "seems" to be coming from the lower end. I've never had a car with a knock so i'm not sure what i'm hearing. Ever since I replaced my leaky fuel injector seals the vacuum leak is gone and the idle returned to normal. Well now at 800 rpms i'm hearing this odd noise. I'm hoping its not the early signs of a rod knock, I know my valve train is noisy as hell. Maybe the clearances are way out of wack? Heres the video.

Oh, and the "knock" sound doesn't change much when the rpms increase, just the valve noise. Any insight is much appreciated.

http://s125.photobucket.com/user/bpe...1_982.mp4.html

yodafan93

hows your oil look? sounds more like a spun bearing or something to me.. rod knocks are louder than that. check your oil for debris/shavings, adjust your valves. if you have time, drop the oil pan and check for play. you could also see for sure if it's a rod.

bpealer

The oil looks fine, i'm not seeing any metal shavings. Gonna change the oil tomorrow and check again. It just seems weird that the noise isn't very consistent, a little random to be a bearing, but I could be wrong. Searching for "rod knock" on youtube isn't making my day much better. lol.

MudHippy

Sounds like a sticky hydraulic lifter(s). But that can't be it, because it doesn't have hydraulic lifters. And mechanical lifters don't have that issue. Plus, they're on top of the engine.

It's probably far more benign. Like maybe a loose motor mount bolt or something.

bpealer

Ok, I spent awhile this morning with a stethoscope listening for the sound. Nothing coming from the oil pan/block, nothing coming the valve covers or exhaust manifolds. Once I poked around the upper timing cover I heard all the glorious noises. Heres a video of it idling warmed up. The video makes the idle sound worse than it is, but notice the noise after giving it a little throttle? Kind of a rattle/tapping sound. Its concentrated near the passenger side of the timing cover. I have plans to do the timing belt/idlers/water pump/oil pump seal, basically everything once the belt is off. Looks like I need to get in there sooner than later.

http://s125.photobucket.com/user/bpe...0_485.mp4.html

bpealer

Ok, pulled the upper timing cover off and looks like the metal backing plate was rubbing on the passenger side cam gear. A few taps and its good now. The problem though is the cam gear looks like its gonna wobble off!! I took a quick video of it. Anybody know what would make it do that? My upper idler seems to be making the bearing bout to explode noise, but the cam gear has me more worried. Maybe it wasn't put back on right, should just be a dowel to locate it and only go in one way. Anyways heres the video. I start my new job tomorrow so I hope this thing isn't ready to fly off.

http://s125.photobucket.com/user/bpe...9_533.mp4.html

MudHippy

I don't know why it's doing that. But it ain't lookin' good. I definitely wouldn't be driving it after seeing that. Not until it's fixed.

Looks like you've got an open can of worms in your hands now...

bpealer

Crap, I checked the torque on the passenger side cam gear and tightened it up some more, not loose but not fully torqued. Well I tried the driver side and I guess I pulled too hard and the gear actually slipped 2 or 3 teeth!! Arg... This is the first vehicle i've worked on that has a belt vs chain, so maybe I assumed the belt would hold. Crap, I don't have time to pull everything and redo the timing....

bpealer

Well I threw on a new timing belt, it was off a tooth anyways. That rattle was the upper idler, bearings are probably shot. I won't be able to get one for at least two weeks. Still not sure about the wobbly cam gear. Maybe its bent/warped? I'm just hoping its not destroying my camshaft too quickly.

Sturmcrow

Man, if I were you I would pull off that cam gear and see what's up with it. That looks terrible! You are correct that is just the bolt and a locating dowel in there. I have read that the two cam gears are the same, just turned around so that the lip is on the front on one and the back on the other. It keeps the belt from walking off.

bpealer

Yea, im gonna have to do tomorrow after work. Its only 6 miles round trip. Once I remove it ill check to see if its warped or anything. Hopefully its just not seated right, not sure how much a new one from toyota would cost.

Sturmcrow

$110
http://www.villagetoyotaparts.com/sh...rimLevel=13968

Which is actually not terrible considering some of the prices they charge. I think the fan bracket is something like $900! I'm not sure I would pay that for the whole engine!
!!

bpealer

Thanks for the link, i'll use the part number and shop around. I gotta start saving up for the 3.4 swap, if this motor ˟˟˟˟s itself I don't wanna put anymore money into it. But hey getting the timing marks lined up correctly made it run a little better. I wanted to replace the oil pump seal while I was in there but couldn't get the drive gear off.

bpealer

Well the cam is definitely bent. Had some 4"x4" 1/8 in steel that was nice and flat and laid it against the gear. About 1/3 of the gear has a 1/8th of an inch gap. Not good. Not sure how it could get bent, probably wedging something in there to remove the crank bolt. Oh, and I pinpointed my noise to both the #1and #2 idlers. I could grab ahold of each one and feel a lot of side to side play. I replaced the larger upper idler and that helped a lot, but the tensioner idler is still clacking around. Gotta order that on friday.

bpealer

Just a little update. I got a good used cam gear and a new tensioner idler. I gotta weld up a cam holder tool tomorrow, but I snugged it down well enough to idle the engine. Good news is the knocking is gone, at least at idle. Im thinking the wobbly cam gear was wreaking havoc on an already failing idler bearing.

The only noise left now is a faint chatter after I rev it up. Its pretty quiet until rpms drop. Its not real loud and I can't pinpoint where its coming from. I can tell its coming from the top end I believe.

For now im anxious to torque the cam gear and test drive it. The only thing I hāvent replaced is the tensioner itself. I noticed every so often the timing belt loses a bit of tension. After restarting and shutting down it'll be tight again. I wonder if this could be causing any noises.

bpealer

Well I've replaced everything timing related now except the tensioner itself. The engine quieted down but the knock is still there. I kinda figured it would be. I kinda figured it would be a rod knock.

I'm going to do a diff drop soon so I'll drop the pan at the same time and see if the crank is messed up. The knock is pretty subtle now so hopefully I can throw in some new bearings and get some more miles out of her. I really don't want to dump too much more money into this engine when I can be saving for a 3.4.

FlamingToast

I feel your pain. I had a rod knock bad enough to take the rod end out of round. I just pulled the head off of mine since I'm hoping to replace the rod. My knock was very load. Sounds like you got lucky enough you might be able to replace bearings to fix it. Plastigauge was $4.50 at my local autozone. I would definitely use it in your case. I still have my diff out and pan exposed so if you want pics or anything let me know. The easiest way for me was to pull the diff and the relay rod for the steering while leaving the cross member in place. That leaves plenty of room to access the bearing caps. Good luck

bpealer

Well I'm 99% sure the rod knock is present. I think I may end up selling. I've had a few guys make offers as I was working on it in the driveway. I simply don't have the money to fix it. I would just toss in new bearings but I've heard that rarely works for long. I love this truck though.

Heres a video after an oil change and all accessories disconnected. Oddly enough pulling the spark plug wires didn't make any change in noise.

http://s125.photobucket.com/user/bpe...8_197.mp4.html

FlamingToast

Sounds exactly like mine did. Sorry man

bpealer

Im just debating on tossing in new bearings or not. I just starting working again so swapping engines is not going to happen for a little bit and its my only ride.