Knocking/clicking sound driving me insane

[Geologist]

I have a very noticeable knocking sound coming from the front of my engine (2UZ). I can't hear it when I'm driving but it's obvious when I'm idling. It stops when I turn the ac ON. Anybody heard of this or experienced it? I'll mention that I recently had the 90k service done (timing belt, water pump, etc changed).

 

[nevada]

bad pully, tensioner, ac clutch?

something in there isnt right.

maybe the ac clutch got damaged, or dinged when they did the belt. and when its not activated it knocking.
there wouldnt be any noise once its locked.
just a thought...

 

[BlackWorksInc]

Simple test, take the drive belt off and run the engine, if it goes away its most likely a bearing/pulley issue.

 

[Geologist]

Thanks for the replies. How long can I run the engine without the drive belt? And would this be covered under a Toyota extended powertrain warranty? I bought one when I purchased the vehicle last year.

 

[BlackWorksInc]

Thanks for the replies. How long can I run the engine without the drive belt? And would this be covered under a Toyota extended powertrain warranty? I bought one when I purchased the vehicle last year.

I wouldn't drive it, but you can run it a good 5-10 minutes without getting too worried, not that you'll really need that long.

 

[Geologist]

I posted a YouTube video of the noise here 2uz-fe strange knocking sound. - YouTube .
BlackWorks, Thanks for the tip. I have a friend coming over to help me pull the drive belt this weekend. After a more intensive investigation, I noticed that the sound does NOT go away when I put the AC on (just gets harder to hear). I seafoamed (through the PCV) last week and it got quieter for a while but then came back. Any input would be helpful. This is driving me nuts, and I have a road trip coming up in a few weeks. Somebody I work with thinks it's a bad tensioner. Is that a possibility?

 

[DC runner]

Ugg. I listened to that several times trying to pin point it. From my speakers it could be any of following (internet diagnosis is always the least accurate, so take with a large grain).
It isn't constant and it almost seems to cycle with the point of the combustion cycle for one cylinder. A crack or small hole in an exhaust manifold might do it. If the hole were located on an individual cylinder exhaust piping.

It could be an issue with a main engine bearing? Is it me or is the noise more located toward the bottom of the engine and engine bay and not towards the upper front? If it is located more towards the engine or rear, it would help eliminate some stuff.

Any codes? Does it speed up when you increase the engine RPM?

Sorry. I tried to take a stab but afraid I am probably not much help.

 

[Stuck CAPS]

I have a very noticeable knocking sound coming from the front of my engine (2UZ). I can't hear it when I'm driving but it's obvious when I'm idling. It stops when I turn the ac ON. Anybody heard of this or experienced it? I'll mention that I recently had the 90k service done (timing belt, water pump, etc changed).

Is the recycler on? When my AC's off, and air recycler's on, i get an annoying tick/knock.

 

[hearno]

I had something similar a few weeks ago after serp belt replacement. video 2013 08 31 21 07 07 - YouTube It ended up being the belt was off a rib on the crank pulley and moving it over cleared it right up. From your video it sounds almost as rhythmical but difficult to pinpoint. As others stated, start by getting the serp belt off and go from there. You can safely idle it long enough to see if it helps with the diagnosis.

 

[Geologist]

Ok, did some messing around with it today and here's what I found out:
1. Almost completely goes away when I put it into drive. The sound is the same in park and neutral, but gets quieter and less frequent when in D.
2. Stethoscoped around the engine bay a bit and found it the loudest on the front right spark plug. The knocking is LOUD in there. I can also feel a tapping on the spark plug when I hear the noise. WTF?!

DCRunner: No codes, and I can't hear it while driving. It gets worse later in the day after a long drive. Can't really hear it in the morning.

Stuck CAPS: I tried turning the recycler off and it didn't change the noise. Damn, I was hoping that was it.

Hearno: I inspected the belt and all grooves line up. I'll report back when I pull the belt this weekend.

Thanks everyone for your help, it's much appreciated

 

[Geologist]

Simple test, take the drive belt off and run the engine, if it goes away its most likely a bearing/pulley issue.

I had something similar a few weeks ago after serp belt replacement. video 2013 08 31 21 07 07 - YouTube It ended up being the belt was off a rib on the crank pulley and moving it over cleared it right up. From your video it sounds almost as rhythmical but difficult to pinpoint. As others stated, start by getting the serp belt off and go from there. You can safely idle it long enough to see if it helps with the diagnosis.

Today I removed the drive belt and the noise continued. I pulled the skid plates and 2 front wheels off and was able to better locate the area the noise seems to be coming from. I think it's coming from the crankshaft. I noticed that the crankshaft pulley doesn't spin perfectly. There is a VERY slight wobble. Is that normal? And could that cause the tapping I feel on the spark plug of cylinder 1? I plan on bringing it back to the shop that did the timing belt, and I want to know what I'm talking about when I go in there.

 

[DC runner]

I hope I am wrong, but I had something very similar happen to me on an old 3vze. Was the crankshaft main bearing going. It went from clanking to dead and the engine went. Mine went in the span of about a day, probably due to under oiling resulting from a sludge build up. I didn't catch it in time.

I would have it professionally checked. If it is a main bearing, then you should cease operation as soon as possible.

 

[Smobien]

Reading this thread made me sad.

 

[DC runner]

Me too. A noise and a wobble means out of tolerance, like when bearings go out.

I hope I am wrong, but you should have it checked professionally and soon.

 

[satanos6668280]

Be sure the crank pulley is tight if its loose even a short drive can gall. The end of the crankshaft then its not pretty. Those bolts need to be torqued to 184 lbft or they will come loose ive seen it ruin many engines mostly the 3vz but others too

 

[GLP]

A slight wobble of the crankshaft pulley is definitely not normal. It's very possible the bolt is coming loose, or there is something messed up with the crankshaft position sensor plate (see photo of it, the plate with teeth, pulley removed).