Joey Link

As I mentioned in my initial purchase thread, my 1989 4Runner with the 3vze seems to have what I believe to be a knock in the bottom end. I was finally able to record these two audio clips and I'm hoping you guys can tell me for sure, since I've never actually heard a 'knock' in person.

http://www.northwestfirearms.com/misc/4runner1.mp3

http://www.northwestfirearms.com/misc/4runner2.mp3

rngrchad

That sound is the sound my truck made after I ran over a chipmunk. Drain your oil and see if you have any chipmunk remains left in the oil pan.....you'll notice hair, white pieces of bones and possibly even a tail still in tact come straight out of your oil-drain hole.

Hope this helps, I delt with the same problem.
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Joey Link

Whoa, for a minute there I thought I was over on Pirate

whokrz

It sounds like you need a 5vze

BigBluePile

iTrader: (3)

I have no idea, I can't play your sounds.

Joey Link

Really? They're just mp3's

Built2Grind

the only rod knock i have heard in person was more low in tone and not as quick, what rpm was this recorded at?

myyota

That doesn`t sould like a rod knock to me, a rod knock would be alot louder and faster, it kind of sounds like a rocker arm hitting the valve cover.

Joey Link

This was at idle, which I believe was around 700 rpm (but I could be wrong about the actual speed).

Almost everyone who's heard it says it doesn't sound like a rod to them. I sure hope everyone is right!

DeathCougar

iTrader: (23)

Sounds like am idler bearing is letting go., or a bearing in an accessory. First try taking off all the belts and running the engine without any of the accessories. If that noise goes away, you can start narrowing it down by putting belts back on.

Joey Link

Awesome, I'll do that tomorrow.

BigBluePile

iTrader: (3)

Sounds very tinny to me, like was said, valve cover. I've never worked or really heard a 3.0 so I'm not a lot of help. It's got a wierd "spool" down sound when coming back to idle. I'd take that freakin fan clutch out so you can actually hear better. Just turn your heater of full blast, I dunno though, this is a 3.0! LOL!!! Have you tried putting a really long pipe or extention on things to feel vibs?

BigBluePile

iTrader: (3)

x2 with DC, sounds like a accessory bearing going.

Joey Link

What do you mean by this?

BigBluePile

iTrader: (3)

Because you're gonna have your motor running without the fan installed. If you turn your heaters(if you have rear heat) on with the fan(s) on full blast it will help to dissipate heat.

Joey Link

Awesome, thanks for clarifying

OutlawMike

That does not sound like rod knock to me at all, I agree with all above, sounds like an accessory or pulley bearing. Rod knock is a more deep, hollow sound, thunk, thunk, as the sound echos in all that cast iron.

There is some really good advice above.

First, pull the fan and the fan clutch, tighten the nuts back down, do not start it without the nuts tightened back down on the pulley behind the fan clutch. You may have to stack some washers on the studs to get the nuts to fully preload the pulley in.

Start it and see if the noise goes away. If not, without the fan making noise you can do some more listening. Again, like said above, blast the heaters and watch the engine temp.

Next, remove the accessory belts one at a time (so you can tell which one is the problem). If they are worn, just cut them off one at a time. Cut one, start it, listen, cut the next, start it, listen. That will eliminate the alternator, power steering pump, and A/C clutch.

If the noise is still present, the next suspects are the idler pulley, the tensioner, and the water pump. They are all part of the timing belt system. You can remove the upper plastic cover very easily to get access to the idler. It is right on top, dead center under the upper cover. Start it with the cover off and listen on the back of that pulley (the part that doesn't rotate), with the stethoscope. See if you can isolate the noise. Also, you can get access to the water pump housing from below with the belts off to listen there, see if it is a water pump bearing.

If you have gotten this far, the next step is to pull the timing belt, a bit more work than an accessory. Search the site, lots of info on how to do that, and the FSM is very good with instructions.

Since the 3VZE does not have rocker arms, it cannot be that. I guess it could be a sticking valve or valve stem bucket smacking around in the head. But, most likely, it seems like an accessory issue.

There are some sheetmetal "shield's" plastic welded into the inside of the valve covers. Maybe one of those came loose and is being hit by a cam lobe? After the timing belt, the next step would be to pull the plenum off the top of the motor and pull the valve covers.

Good luck

Joey Link

Thanks again for all your help guys. Just finished my breakfast of pizza and coke zero, heading out to the garage now

I forgot to mention, the previous owner said he just replaced the timing belt and water pump. When I purchased the rig he told me the valves needed to be adjusted, and that was the sound I was hearing. However, when I got home, I saw he purchased a rod bearing and an oil pan gasket, which leads me to believe he also thought it was a rod bearing. Either he got in there and found that wasn't the cause or he got in there and found it was too far gone to replace without pulling the motor, I'm not sure (and naturally, he's not answering my calls now).