Shananigan

Hello,

I have a 1995 Toyota 4Runner: 4X4, Manual Transmission, 3.0L V6 (3VZ-E Engine).

The truck itself has 233,XXX miles on it, but the engine (newer) has under 100,000. Plus many of the components have been replaced.

I am due to go on a 1,000 mile, two day trek Friday to a summer job. On Sunday, my Dad and I went checked all the fluids in the 4runner and changed the motor oil 10w-40, oil filter, and air filter. Everything looked great, everything was topped off, the old oil looked good. I've never had a problem with this vehicle.

On Monday I put in a bottle of STP Injector cleaner and filled my gas tank. I figured it couldn't hurt anything, and I wanted to do everything I could to make sure my trip ran smoothly. Well, later that evening (after I had driven about 40 miles), I noticed the engine making a slight 'knocking' noise when it was sitting at an idle. I brought it to my dad's attention, but since it was getting late we decided to tackle it in the morning.

Tuesday morning, I fired up the 4runner to investigate the noise and it was gone. We waited for a minute, but decided it was a fluke and didn't think much of it. Later that day though, I noticed the noise again when I was sitting at an idle after running a few errands in town.

Since then, we have been trying to figure out was is happening, but have had no luck. When the engine is cold and you fire it up -the noise isn't there. It is when the truck has had the chance to warm up and after the oil has thinned, that the noise appears.

The noise stays the same when I push the clutch in. When I rev the engine, the rhythm of the knocking speeds up with the engine but past 1,500-2,000 RPM I can't hear it. I don't know if that because it has stopped, or because the engine is drowning it out. It is a loud enough noise to hear it from inside the cab, with the doors shut, when the truck is at an idle.

A friend of mine listened to it this afternoon with a vehicle stethoscope type deal, and said he heard the noise mostly under the engine through the oil pan and along the sides of the engine. He is a mechanic, but doesn't deal much with the Toyota V6.

The noise definitely seems to be coming predominately from the bottom, and I would say louder on the passenger side. It drives perfectly fine however, the oil pressure gauge is reading fine -my levels are up. It's just the noise that is bothering me.

I am pressed for time here, seeing as I need to make it to my job by early next week. If I can't get this figured our and/or fixed in the next day or so, I will have to find a flight and start shipping out my things.

Any and all advice is greatly appreciated!! Thank you!!

HighLux

Check the shields on you cat

Shananigan

Okay! I was kind of looking that up, I've read something like that would make more of a rattling noise. Can it cause a rhythmic noise as well? Do you think it could be the oil filter? I just looked up and saw that "Fram" oil filters are notorious for being bad and causing a "knocking" sound.

I feel like that would have happened immediately after changing the oil though and I don't understand why the noise wouldn't be there when the oil was still thick.

BioHazard050

It may be the fuel system. You ran that cleaner through there and it loosened up all the junk that built up. I ran some injector cleaner through my '89 once and my injectors/Fuel pressure regulator started ticking like mad.

Shananigan

Did it stop once that fuel was gone? Was the noise constant or would it come and go. I thought about draining this tank.

BioHazard050

It stayed. Its not a real issue, just a nuisance.

Shananigan

Alrighty, thanks for the replies. I just got back from the mechanic. He took a listen to it and is now saying he thinks it could be some sort of bearing underneath just clacking around. He said he wasn't worried about the noise and that it will make my trip "more of an adventure" but he wouldn't worry to much as long as my oil pressure is good and it is running smoothly.

I don't know what to do. I guess I should think of worse case scenario of taking it and that would be having the entire thing blow-up and having to get an entirely new engine.

Anyone have any ball park ideas of what it would cost to replace the engine? 3.0L V6 3VZ-E

BioHazard050

The 3vze is notorious for being a noisy engine. But as long as its running smooth, and the oil pressures good, nothing to worry about.