pitviper33

Hi all. I bought my truck not long ago, and it had a bad tapping sound from the start. I discovered that the timing chain guide was broken, so I assumed the chain hitting the timing cover was the cause. I replaced the chain, sprockets, guides, and tensioner with parts from engbldr. Now that that's all finished, I still have the tapping noise. It's much less frequent than before, but it's definitely still there. It seems to be throttle dependent. It's the worst at part throttle above 3krpm. I hear just a bit of it during shifts, and I can get it to sustain at low load holding the engine at about 3250rpm.

Can anybody give any clues? Is my tensioner not functioning properly? Is it something else completely? Does a noise happening at light load only sound familiar to anybody? I recorded a good clip of the noise. If somebody can suggest how to host the mp3, you can all hear.

92 TOY

fuel injectors?

Monochrome

Did you record it with a digital camera? If so, create an account on youtube.com and upload it there. I'm curious to hear it as well.

I have a similar problem under load where I hear a tapping/pinging noise. I'm still trying to diagnose it but I'm curious if our sounds are any different. I'll try and record mine as well.

toyota4x4907

valves lash out of spec?
piston slap?
main/rod bearings giving away?
fuel injectors?
normal 22r/e sound?

92 TOY

Yeah, that's why i said that.
they are noisy.

pitviper33

I originally noticed the the timing chain guide when I was adjusting valves. That wasn't long ago, so lash should be fine.
I don't know what valve slap sounds like.
I felt the main and rod bearings when I had the pan off doing the chain. None of them were bad enough to feel loose by hand. I realize that's not the best check, but at least it's something.
Fuel injectors is exactly what it sounds like. Diesel fuel injectors. I kid, but really I don't know what noisy fuel injectors sound like. This seems louder than any noise I'd expect to come from an injector.
I don't know what a normal 22RE sounds like. The only person I know with one lives on the west coast. I emailed him my sound clip, and it didn't sound familiar to him.

I recorded the sound with my phone. So it's just audio, a mp3. I don't think Youtube lets you upload mp3s.

pitviper33

You should be able to hear the clip here: http://www.houndbite.com/?houndbite=17313

1993 Toyota 22RE tapping
Recording from inside the cabin. Launch in first gear. Shift into second near 3500rpm. Slight tapping heard at partial throttle when coming out of first gear and again going into second gear. Then engine speed held around 3250rpm in second gear to sustain tapping noise.

olharleyman

check your fan maybe it is hitting the shroud off and on maybe a bolt came out of the shroud and it moves just enough to hit it off and on.

toyota4x4907

I had that sound after I took the valve cover off to adjust valves and didnt tighten the metal bracket thing where all the VSVs are on top of the VC!!.

yodathespian87

Valve clicking is a high pitch constant tap, rod would would be deaper and constant with RPM. Did you check you valve clearance cause I'm adjusting mine tonight as they are out of spec and causing mine to make some noise. I don't know how you felt the rods with your hands when the pan was off casue there is a splash on there covering them up so did you take that off as well and then how did you manuver around the front diff? Just wondering cause on my trucks there is no space for me (and I'm only 135lbs) to fit my hand in there.

pitviper33

The fan? I have to admit, I did not think of that. I'll check it tonight. I was thinking it sounded more metallic than that, but anything's possible.

I'll check everything on top of the valve cover tonight too. But what's a VSV?

Yep, I've adjusted the valves. I had to take the oil pan all the way off to get all the junk from the broken chain guide out. I dropped the differential to do it, but I didn't have to pull the axles out. Even doing that it was really tricky to get that splash shield around the oil pick up screen.

toyota4x4907

VSV = Vacuum Switching Valve. They are the little red/green/black or whatever plastic valve thingies with vacuum lines coming off of them on the top of the engine.

skinnadoor

Ok man this is going to sound crazy, but a few years ago, i got my timing chain done and the person that did it, brought it back to my place after it was all done, and it had a pretty tap to it, worse then when i gave it to him.

I sat around here and got on yotatech, and after a few days someone posted, " Your valve cover is on too tight, undo the bolts and re-torque them to 40 inch pounds "

To my shock and amazment, i went out and the cover was on so tight that you could not see the rubber busings on the four bolts, as i started backing them off, the sound went away... timing job was excellent.

40 inch pounds on the 4 valve cover bolts.... that's barely anything, and that's the reason..... too tight, lots of noise.

I hope this helps.

toyota4x4907

^ Aye. Very true. Good thinking. Its like tighten them to where you cant with your fingers anymore, then tighten them 1/2-3/4 more turn with a wrench. maybe not even that much.

WatsonToyota

my VSV's used to do that, more so when she was cold, i wedged a little chunk of wood under it and that kept it quiet...

pitviper33

Well, I went under the hood and checked a few things
Fan seems to have plenty of clearance to its shroud and everything else.
All bolts holding things down on top of the vale cover are tight.
I re-torqued the valve cover bolts to 40inlbf.

I drove it to work this morning, and the noise is still there. It actually seemed just a bit quieter, but I'm attributing that to a placebo effect. What is the little canister that looks like a diaphragm can on the left side of the valve cover, above the VSVs in toyota4x4907's picture? That was kind of resting on the valve cover. I'm not sure where it's supposed to be mounted, so I just pulled off a vacuum hose and plugged it back in so that it rests on top of the vacuum line to the brake booster. It's not elegant, but it got it off of the valve cover.

So does anybody else think they recognize the noise in my sound clip? Does it sound at all like what you guys have heard from a timing chain slapping its guide or the housing? I ask that specifically just because that's the biggest thing I've messed with on the truck, and I don't want to have done something wrong. If it's something tapping on the outside of the engine, I'll be a lot less worried that it's a time bomb. I'll still want to fix it of course, but at least I'll feel better in the mean time.

Thanks again for all the help everybody. I'm sure I/we will get to the bottom of this.

yodathespian87

The only questions I know 100% of the answer is that my VSVs are not on top of the valve cover. Mine are mounted on the fender walls. Good luck

Karlton

Did you try using a stethoscope (or a piece of vinyl tubing in your ear) to try to isolate the tapping sound? Is it louder around the head? Or the bottom of the block?

Feeling for play in the rod bearings with the head on would be difficult due to the compression in the cylinders. Did you have the spark plugs out at the time?

I had a similar throttle-dependent tapping that eventually turned into an awful knock. In my case the tapping would NOT occur when I was on the throttle ..... Only between gears, and when cruising at a consistent RPM (on the higher end). It ended up being a bad rod bearing.

I wasn't sure it was the bearing at first. I had the plugs out and was turning the crankshaft back and forth to try to listen for any slop and everything seemed smooth. Eventually the bearing spun and wore down to a point where there was enough slop for the piston to occasionally tap the head and make an awful racket.

Once I had the head off it was immediately apparent the bearing was bad as turning the crank back and forth exposed which rod was knocking.

But maybe your situation is different. I hope so.

At one time I also had the loose VSV issue mentioned earlier, as well as the loose exhaust hanger holding the downpipe to the bell-housing.

Good luck!

pitviper33

I've got a stethoscope, but it doesn't make the noise under no load, only at light load. So that means I need to be on the road to hear it. I might try listening in neutral tonight anyway just to see if it's there but faint.

When you had your rod knock sound, did it sound like the noise in my sound clip?

BigBluePile

iTrader: (3)

Man, I tell you what, that sounds like a rod knock to me. I'd think it would get worse with a load. My truck had that about 3200rpms too. The #1 one rod bearings were going bad. I don't know if you can check from the bottom, but I pulled the head and had the cylinders all the way up and a little more. I pushed down on the pistons and the only one that went "clunk" was the number one 'cause it had a spun bearing.