96tacoma96

I have a 96 Tacoma with a 3.4L. It's the 4x4 5 speed. I bought it with an engine knock. The guy I bought it from claimed that it was a lifter knock. It was a loud deep knocking noise. I put 3 bottles of lifter cleaner in the engine. That did not help. Then I was testing out the 4 wheel drive after taking it home, and the knocking stopped. The knocking was replaced by a new noise. It's a squeaking, knocking noise. It sounds a little bit like a Bad Bering sound. Anyone know what this could be? It sounds kinda like it's coming from the drivers side. It makes the noise at all times. It makes the noise when you rev it, when it's idoling, and when it's warm or cold. It never doesn't make the noise. Could it have somthing to do with the cam shafts? Or the transmission? I hear it no matter where I listen from. Anyone have any idea? Anyone ever had the same problem.

Let me know. Thanks

HighLux

3.4's usually dont have a lifeter noise.....they are dohc motor. it would be up top. a low noise is a rod knock.


post a video of it and we will know for sure. get phone close to motor.

96tacoma96

Here's a link to the video of it. Listen closely

HighLux

Thata a rod knock boss. sorry.

HighLux

One last test. pull of a sparkplug wire at a time . when you hit the cylinder aftected....if it quiets down some...def a rod.

96tacoma96

Ok I'll try that. That was the knocking noise. It's making a little different noise now. Less knocking, more squeeky knocking/ticking now. The new video won't upload. That was yesterday's video. I'll try taking out the plugs

HighLux

Poor 3.4 They are usaully do good. I dont rev mine alot....I keep the rpms low. I think if you rap these things out alot and run em hard...this is what happens. Def a sign of abuse.

96tacoma96

Yes I agree completely. This whole Tacoma was just trashed and not cared for. This is a good engine, someone just didn't change the oil all it's life, and went hard on it. It had a new engine put in at 125k, I have receipts and everything. It has 250k miles now.

HighLux

lemme know bout spark plug trick....ill be on and off all eve

it will confirm the rod for sure. If a plug off on affected cylinder quiets it down some you know its a rod.

If its a rod smaking aroung on the crank....that motors in deep trouble.

96tacoma96

I tried it. I could only take out 2 of them on the drivers side. I didn't want to take out the coils, I don't think it's on the coil side though. I noticed maybe a small difference when the drivers side middle plug was out. It may have just been because of the misfire noise smothering the knocking noise. I couldn't get the far plug out. If it's not a rod, what do you think it could be? Somthing to do with the cam shafts possibly?

HighLux

It could be a rocker arm , but I never ever have heard of a valvetrain noise in one of these.

They either.. radiator messes up and trans fluid and oil mix. kills em sometimes.

A rod goes once in a blue moon. I suspect revving the crap out of them.

Its not good either way.

First place to really dig in is to pop a valve cover off and inspect the valvetrain. a noise like that leaves tell tale carnage...should be no brainer to see.

I realistically expect my 99 runners 3.4 to go 300k easy. These things can get rediculously high miles, and still hold some value.

HighLux

I just watched the video again. Like 10th time. It almost seems to fast for a rod knock. I cant wait to see under the valve cover.

rworegon

Could that be a water pump falling apart and changing in intensity as the RPMs go up? Or, very bad idler pulleys which are also driven by the timing belt? It's time to start looking inside......

96tacoma96

I may take the valve covers off to check it out soon, I know someone who can put a new engine in for me. I know that these things are worth lots of money running good. The knocking does get faster when you give it gas. The oil pressure light on the engine is on. It comes on and flickers at low RPM. At high RPM, the oil pressure light goes off and stays off until you get back down to idol RMP. I'm not sure if this means anything or not. It had a new water pump 125k miles ago. This whole engine was rebuilt at 125k miles, because rod #3 was bent. Who ever owned it abused it. Making it the peice of junk it is today.

HighLux

a loose big end of the rod would crash oil presuure.

vital22re

iTrader: (2)

Time to replace the motor. When you have the motor out drop the pan. I'm fairly sure you'll have a spun bearing or just a toasted bearing.

DRCOFFEE

Cracked flywheel comes to mind. It doesnt sound like a knock to me. Sounds more like metal slapping against metal. You can use a long screwdriver like a stethoscope and listen to various parts of the engine. You simply put the plastic end to your ear and touch the steel end to the engine. Just dont put it by the moving belts.

j2the-e

These engines don't have lifters or rocker arms. That sounds like a rod bearing is missing. How sparkly is the oil?
I would stop now before you cause more damage. Time to pull the engine out and pull the pan off. I wouldn't bother doing anything in the truck. It will need to come out anyway

Jomoka

It doesn't quite sound like a rod knock to me. Those are usually a bit deeper sounding, clunkier. And they tend to come and go with varying loads on the engine (revving it up and down). This sounds a little tappier, and doesn't vary much as the engine revs and slows.

I'd pull the valve covers first and see what's under there. I'm imagining you'll see something off inside there.

It very well could be a rod bearing, cameras are often a bit off in terms of picking up the whole spectrum of sound. As already mentioned, drain the oil, look for sparkles. If that's a rod bearing, there will be plenty of confetti in the oil. Also possibly consider taking the oil filter off and cutting it open to see what it's been catching.

But I would def pull the VC's first to check for valvetrain shens before pulling the motor.

HighLux

Uh...they have bucket style lifters.