Well, I have had the 4Runner running for about the last 15 minutes. I pulled each of the plugs on the drivers side one at a time and turned the motor over. You can not hear any noise while the engine is turning over with the coil wire off. It turns over fine with absolutely no odd noises. With a spark plug pulled and turning it over it sounds fine. All the driver side plugs looked just fine.
The noise really seems to be coming from the "Carburetor Area". I put a tube to my ear and right below the carb, and toward the windshield the noise is the loudest. It sounds like a rocker are is broken or something like that. The only noise I can compare it to is when a rocker are was broken on my old race car. It had a loud peck or knock. This is what it sounds like. Is there anything in this area that could cause this type of noise?
Any thoughts?

 

Another thing, is also kind of sounds like a real loud spark knock, and reacts the same way. When you rev it up you can hear the noise, but it quiets down while it is idling down. It does make the noise at idle, but will quit some times for 30 seconds or more.
Any help is appreciated.

 

You sound like you're new to the 2nd gen 4Runner and 3.0's. I hate to be the harbinger of bad news, but the 3.0 has two problems that crop up...expecially in 1994 and earlier models. They throw rods and the head gaskets leak. Both are expensive to fix. I'd get it into a Toyota mechanic of some sort and get it checked out. What you're describing isn't water pump, and our engines don't have hydralic lifters so you're going to have to look elswhere. Maybe cracked or defective distributor cap, spark splug wires, or something really bad like a rod loosening up. Get it checked out.

 

Mine was knocking on the same side it turned out to be the rod end bearings were going. I had to rebuild the engine. Thick lucas oil will quiet it down for a while but I would rebuild it soon before a rod goes through the block.

 

If I don't get anywhere today, I am going to take it into the local Toyota dealer early this week. It just does not sound like a rod to me, more like a screw or something has gotten on top of a piston.

 

A screw on top of the piston would have already either become part of the piston or part of the cylinder. Good luck. Not sure what it could be.

 

mine does the same terrible knocking sound, I really notice it when I'm on this trail in my neighborhood going up a hill at lower rpm's. and sometimes on the road idling and accelerating in 1st and 2nd.
still haven't gotten around to having it looked at, but I'm worried it's ready to throw a rod,. good luck with it and let us know what turns up

btw: mine has made this sound since I got it three and a half years ago with 158k. it now has 183k on it, and may make the sound a bit worse than before.. but it's still runnin *knock on wood*

 

The only time mine makes a sound even resembling a knock is always at 3k or just a TAD above it and its most noticeable in about 2nd gear...not sure what it is. But I've left it alone as the 3.0 is a pretty noisy engine anyway.

Fink

 

oh and I've had the spark plugs replaced, water pump and timing belt. didn't change the knock. needa do the wires, cap and rotor though,.

 

it is noisy, but I posted about test driving an 89 extended cab a couple days back.. and let me tell you... the difference between that engine and mine was like night and day, it ran like it was brand new.. none of the noises mine makes what-so-ever.

nobody replied to that post though, and he was asking 6,250 n wouldn't come down from that, which seemed too high to me.

 

I bought the 4Runner for $3650.00. It has 163,000 miles on it, but the outside and inside look great. I really thought I got a great buy until I started having this problem. I have a friend who is a mechanic. He is on his way over to take a look. I also called a couple of Toyota dealerships and talked to the service depts. EAch of them said that they have experienced carbon build up on the pistons coming lose and making this type of noise. I know I described it as a knock, but it just does not sound like a rod bearing or anything like this. I would bet money that the sound is coming from the top of the motor. But, I have bet money before and lost it.