3.0 Tapping

[91Toyota4x4]

My 91 3.0 is making this tapping type of sound.  Don't quite know how to describe it, it's not a totally metallic sound.  Almost like a loud sewing machine.  When under load it gets a little louder and turns a little more "pingy."  Has anyone else had anything like this on a 3.0L?  It's got around 110k on it.

Thanks for any replys!

[awhotrods]

how many miles does it have? its most likely rod knock.      

[BLACKDOG]

110k
Sorry, I've never heard anything like that coming from my engine, but I would also consider a rod knock

[reklund5]

Light tapping sound or heavy really loud sound?

3.0s sound like death when they have a rod knock.  I'd suspect loose valves (the exhaust valves loosen up over time) or fuel injector noise if it's a really light tap sound.  Can you post up a sound byte or something?

Ryan

[91Toyota4x4]

It was pretty light but I think it's getting worse.  It's been doing it for the 2 or 3 years I've had the truck really light al first and only got loader under acceleraltion.  Now it's a little louder, I just hate this kind of thing, the noise ugs the hell out of me because in english tap tap tap tap translates into $ $ $ $.....  And my clutch needs replacing soon too.  I have never done either of these and dont want to mess something up trying.

[reklund5]

They're not that bad to work on....I've done a clutch in a 3.0 on my back in my garage at home in under 4 hours- including time for the machine shop to resurface the flywheel 

If the tapping noise has been going on for that long, and its getting worse, maybe  you have an exhaust leak at one of the manifolds or the crossover pipe?  Did the truck ever get the V06 headgasket recall campaign performed?  I'd check those manifold bolts and make sure they're snug (not too tight, don't want to pull the studs outta the head).  You can access the top ones from the top, and the bottom ones from the side if  you remove the fender skirts.  As I said it could be the valves needing adjustment, but that doesn't sound right if it gets worse with load.  Valve clearance adjustment is a little more involved, and requires removal of the upper intake plenum.  You may want to shell out for your local toyota specialty independent shop to do that or take it to the dealer.  Expect to pay around 6 hours of labor for a valve adjustment. 

Where are you located?

Ryan

[91Toyota4x4]

I'm in Gainesville, FL/Melbourne, FL.

How would an exhaust leak at the manifold be causing a knocking sound like that?  It's probably rod knock, that's what I had figured initially.  I bought this truck used so I have no idea if it has been serviced under the recall.  I just changed the oil and saw no sign of a head gasket leak there, but that doesn't mean there isn't one.  Hasn't been losing coolant either.

Thanks for the info.

[reklund5]

An exhaust leak at the manifold creats sort of a tapping/clicking sound usually audible from the cabin.  I was just throwing out an idea and maybe  a ray of hope there...

Chances are it IS a rod knock, but I was just hoping you'd exhausted all other possibilities before tearing the engine down 

If you email me your VIN I can run it at work and let you know if the HG campaign has been completed ( I'm a Toyota technician at a local dealership)

The 3.0's USUALLY show signs of a blown headgasket by blowing huge plumes of white smoke outta the tailpipe (water in the cylinders) but USUALLY won't mix oil/water.  Usually.

Ryan

[email protected]

[91Toyota4x4]

I'll try to get the VIN for you and I will check the manifold, but you're probably right it's a rod

Thanks for your help

[91Toyota4x4]

Sent you my VIN

[keith3516]

It is likely a rod bearing.  I had the same noise you are describing and couldn't believe that's what it was, but that was it.  #2 and #6 both coming apart - ugly, but at least I caught it before I damaged the crank.  One other note - took me almost 8 hours to get that thing out of the truck - more wires, hoses, and lines than you can shake a stick at.  Took lots of pix.

However, now that I have my 3.0 scattered all over my garage, I'm really having a hard time finding overhaul options other than stock.  Does anyone know of a quality supplier of performance enginie parts for these engines?  Mine is out of a 94 4runner.

[reklund5]

Contact DOA Racing Engines or LC engineering

[91Toyota4x4]

How hard is it to fix the thing once you get in there?  I've never done anything like that to my truck so I don't have alot of know how, I am mechanically inclined though

[79coyotefrg]

if your mech inclined you can probably replace your rod and main bearings,    what your describing sounds like a main bearing knock

[91Toyota4x4]

Ok, I have spring break comming up so I'm going to try to take care of some of this stuff then.  Replacing clutch, installing a CB, and thinking about trying to fix the motor. 

Now, what does it take to get into there to get to the rod/main bearings?  I don't know much about this but I'm pretty sure you just need to drop the oil pan and it exposes it all.  But, do you really need to take the motor out to do it?  All of that IFS crap looks like it would be in the way. 

Thanks for any advice!

[reklund5]

The front diff drops out of the way pretty easily, then the oil pan should drop right off. 

[91Toyota4x4]

I'm going in way over my head!

But I did stay at a Holiday Inn last night 

Once all up in dat will it be obvious if the bearings are toast?  Like play or they just look obviously trashed? Also, does it require some super duper specialized tools to get them off?  Like presses ect.   

[reklund5]

No, it won't be too obvious they're trash until you get 'em out.  The bearings are actually in two pieces, like two half moons ( and )
You'll have to remove the rod caps/main caps to inspect the bearings.  Loosen all and replace only one at a time!  If you've never done this, I'd suggest getting a competent mechanic friend to hang out and look over your shoulder...

No special tools- just a 14mm and 17mm socket to remove the bearing caps and look at them.  You really need to plastiguage the bearings and see if you need to get a different size or have some machine work done.  This is not something you should do unless you're prepared to overhaul the entire engine- if there is damage to the crank or a rod, you're talking total rebuild time and some machine work...  Just a friendly work of caution 



Ryan

[91Toyota4x4]

Well I could take it all apart and plastiguage to see if anything is out of tolerance and if it is then put it back together and have someone else take care of it 

Keep in mind that I'm going to check compression and other crap before this, probably pour in some seaform to clean the carbon and crap.  Oh joy

[robinhood4x4]

Keep in mind the 3.0 is notorious for an injector tapping noise and this is quite normal.  Put your finger on the fuel pressure regulator and see if you can feel the tapping.  If you can, it's the injectors.  Alternatively, you can take a small hose or tube and stick one end in your ear and move the other end around the engine.  The noise will get louder the closer you get.