I recently purchased a 94 4Runner. I have only ran it for about 2 weeks and 500 miles. It was running just fine when it started to have a really loud knocking noise in the motor. The noise sounds like it is coming from the driver's side, at the top of the engine. This is what I think, no way of knowing for sure. I pulled off the driver's side valve cover because it sounded like a spring was broken or something. Everything here looked just fine.
The odd thing is that the noise is not there all the time. Sometimes it will run for 30 to 45 seconds and sound normal, then this knocking comes back. I pulled each plug wire one at a time and it still knocks.
Anyone experience anything like this?
Any info is appreciated.
Thanks

 

If its truly a knocking that could be something serious, I'd get it checked out by a mechanic right away. If its more of a ticking noise then thats probably just the normal noise that our 3.0's make all the time.

Fink

 

Yea, it is pretty loud. What really has me wondering is how it just seems to totally stop at times. It is definetly louder than a "tick". It sounds like something is hitting something else, if this makes any sense. I am going to look more, but if I do not find anything by Monday, I will see a dealer. I was just hoping someone else had experienced this.
Thx

 

you might want to try a search as well, if you haven't yet.

 

Fink

 

I have done multiple searches, but have come up empty. The only thread that was remotely close to my search said that his problem was the water pump. I am waiting for a repair manual so I have not even looked for the water pump. I thought about taking off all the belts and starting it for a few seconds and see if the knocking stops. I may be wrong but it does seem like it is inside the motor, but I cannot tell for sure. I don't know what else it could be. It is just so odd, because it seems to be running great, except for the knocking noise. Any other ideas on how to diagnosis this one?
Thanks

 

Has anyone had a problem with a water pump that causes a noise like this?
Thx

 

You need to have a compression test done. If you want to kill some time before you do that, pull the plugs and take a look at them. If you need help with their condition post a pic of the plug in question. We can help from there.

Now get that compression test done.

 

when my water pump went out, it just leaked, not a whole lot, but enough for me to notice. it never made any noises.

 

I appreciate all the info. I am going to start working on it today so I will keep you posted on what I find.
Thanks Again