Cannot find source of knocking/ticking sound (1 Viewer)

[Pavs323]

About 10 days ago some smoke started coming from the engine and I heard a light knocking/ticking noise and eventually it was accompanied by a bit of a chirping sound. I hit the throttle a bit and the ticking sound increased in frequency. The temperature was fine so I knew it wasn’t the cooling system. I thought it sounded more intense from the bottom, but with the engine already being inherently loud as you all know, I wasn’t positive. I had no choice but to drive it home. I took is as easy as possible and took the shortest route, and had absolutely zero performance issues on the drive back, which gave me hope it was nothing catastrophic. The smoke also went away once I got home, but I thought that could have been also that it was just being blown away and not noticeable when I driving too. I started it up again a couple hours and still heard the noise. I didn’t see smoke then, but immediately turned the engine off upon hearing the noise to prevent any more damage.

I pulled the oil pan and inspected all the rods and none of them are broken. There are zero metal shavings in the pan, crank case, or the oil. I’ve checked all the bearings down there and those seem fine. In fact, I was pleasantly surprised how well it did look down there.

So I took the valve cover off, and inspected everything up top. Similarly, nothing feels or looks broken up there. The valve springs are fine, the lifters seem to be fine, the pushrods feel fine, etc.

So at this point, I’m kind of lost and was wondering if anybody had any other ideas. I wouldn’t be shocked if I am overthinking this and the solution is right in front of my face. At this point im thinking maybe bad valve seals? I don’t know, I’m just a DIY guy and I know plenty of you know more than I ever will, so I figured it couldn’t hurt to get some advice.

Any advice helps, thanks!

 

[gbogh]

Chirp & tick could be two different things.
When you pulled the valve cover off, did you check valve lash?
How old are your accessory belts?
Do you have access to mechanics stethoscope?

 

[OSS]

Maybe it’s an ancillary component and not the engine proper - though those things tend to spin fast and not tick.
1. Alternator
2. Smog pump (if you’ve got one)
3. AC bearing
4. Power steering pump
5. Loose fan clutch nuts making fan loose

Also my 2F sometimes made clunky noises at idle (when the engine only had 60K on it in 1989) and did it off and on for 30 years. I never could pinpoint where or what the sound was, and after 290,000 miles - engine still ran fine.

So some random noises aren’t necessarily death sentences. At least mine wasn’t.

 

[Pavs323]

Chirp & tick could be two different things.
When you pulled the valve cover off, did you check valve lash?
How old are your accessory belts?
Do you have access to mechanics stethoscope?

I replaced the belts a couple years ago and they dont appear to be worn out. I don’t know maybe for the chirp I very well could have spilled a bit of coolant on one of the belts when I pulled the reservoir hose out from the reservoir to make sure everything looks fine in there. The fact the noise did go away makes me think this may have happened. (Here’s that overthinking part I am talking about!)

I have not checked valve lash yet as I can’t find my feeler gauge, but it will be the next thing I check, good idea.
Thanks.

 

[Pavs323]

Maybe it’s an ancillary component and not the engine proper - though those things tend to spin fast and not tick.
1. Alternator
2. Smog pump (if you’ve got one)
3. AC bearing
4. Power steering pump
5. Loose fan clutch nuts making fan loose

Also my 2F sometimes made clunky noises at idle (when the engine only had 60K on it in 1989) and did it off and on for 30 years. I never could pinpoint where or what the sound was, and after 290,000 miles - engine still ran fine.

So some random noises aren’t necessarily death sentences. At least mine wasn’t.

I replaced the alternator a couple months ago and have desmoged. I’ll check the rest. Thanks for the reply!

 

[duncanrm]

Its worth checking for an exhaust leak as well.

If you haven't already, a good trick for tracking down noise is to use a length of garden hose, 2-3'.. put one end to your ear and use the other end to probe around the engine bay - it can really assist in tracking down a noise.

 

[micruz60]

Regarding the chirp, is it happening when the clutch pedal is pressed to the floor? -that could be a throwout bearing / pilot bearing.
These 2F engines are notoriously tough, and when at proper temps, proper valve lash, proper timing, they sound like a sewing machine ticking-swishing musically.
I definitely was overthinking this stuff in the past, like 10-15 years ago, now I just drive and change oil, tires, belts.

 

[g-man]

you can remove the power steering/alternator belt and run it for a few minutes. Process of elimination. Again with the fan/smog pump belt. Just be sure to do it cold and not too long so you don't overheat.

 

[CruiserTrash]

Maybe it’s an ancillary component and not the engine proper - though those things tend to spin fast and not tick.
1. Alternator
2. Smog pump (if you’ve got one)
3. AC bearing
4. Power steering pump
5. Loose fan clutch nuts making fan loose

Also my 2F sometimes made clunky noises at idle (when the engine only had 60K on it in 1989) and did it off and on for 30 years. I never could pinpoint where or what the sound was, and after 290,000 miles - engine still ran fine.

So some random noises aren’t necessarily death sentences. At least mine wasn’t.

The clunky noises you’re referring to … would you describe that as sounding “hollow”. I have a weird sound I’ve been trying to trace from the lower front of the motor - accessories or maybe even in the oil pan. It comes and goes, and even when it’s there it might skip a few beats.

You know when you put your finger in your cheek and pop it? It’s a cross between how that sounds hollow and a dull metal thud. The frequency is a little more than 1x per second at idle. Just curious if your noise might be the same mystery one I hear now and again.

@Pavs323 As OSS mentioned, the accessories are a likely culprit. Smog pumps definitely “chirp” when new and breaking in, and when old and about to die … but you’re desmogged. PS pump front bushing trashed, so the axle piece is hopping around when rotating? I would also suggest using a stethoscope to check for exhaust leaks. I once thought I had a bad rod knock but it turned out to be an exhaust leak.

 

[OSS]

The clunky noises you’re referring to … would you describe that as sounding “hollow”. I have a weird sound I’ve been trying to trace from the lower front of the motor

That’s exactly what it was and like you said - front lower.
On my engine, the rhythmic clunk only happened at idle. Slow idle. Never when engine was turning fast or while driving.
It went away when the idle was really smooth (after a full tune up) and seemed noisier on a hot slow idling engine.
My guess was that it was crank shaft thrust of some sort banging something against something else when the engine wasn’t idling smooth.

 

[BGarcia88FJ62]

The "tick" sounds to me like it may be a lifter misbehaving. The chirp could be anything mentioned above.
Next oil change add a bottle of "Marvel Mystery Oil" if it is a lifter it'll quite it down.(Don't laugh the stuff work's)

 

[ToyotaMatt]

About 10 days ago some smoke started coming from the engine and I heard a light knocking/ticking noise and eventually it was accompanied by a bit of a chirping sound. I hit the throttle a bit and the ticking sound increased in frequency. The temperature was fine so I knew it wasn’t the cooling system. I thought it sounded more intense from the bottom, but with the engine already being inherently loud as you all know, I wasn’t positive. I had no choice but to drive it home. I took is as easy as possible and took the shortest route, and had absolutely zero performance issues on the drive back, which gave me hope it was nothing catastrophic. The smoke also went away once I got home, but I thought that could have been also that it was just being blown away and not noticeable when I driving too. I started it up again a couple hours and still heard the noise. I didn’t see smoke then, but immediately turned the engine off upon hearing the noise to prevent any more damage.

I pulled the oil pan and inspected all the rods and none of them are broken. There are zero metal shavings in the pan, crank case, or the oil. I’ve checked all the bearings down there and those seem fine. In fact, I was pleasantly surprised how well it did look down there.

So I took the valve cover off, and inspected everything up top. Similarly, nothing feels or looks broken up there. The valve springs are fine, the lifters seem to be fine, the pushrods feel fine, etc.

So at this point, I’m kind of lost and was wondering if anybody had any other ideas. I wouldn’t be shocked if I am overthinking this and the solution is right in front of my face. At this point im thinking maybe bad valve seals? I don’t know, I’m just a DIY guy and I know plenty of you know more than I ever will, so I figured it couldn’t hurt to get some advice.

Any advice helps, thanks!

 

[NeverGiveUpYota]

Push rod? Could be one is slightly bent. I found one in mine prior to rebuild.

 

[CruiserTrash]

@OSS That's an interesting theory. I was also thinking it could be the oil pump, maybe an air bubble in it that made a hollow gulping sound that resonated via the oil pan so it sounded more like a clunk. I've talked with one other person who has heard the same exact thing. And you're right - only at slow warm/hot idle.

Sorry for the hijack here.

 

[raymond2335]

That’s exactly what it was and like you said - front lower.
On my engine, the rhythmic clunk only happened at idle. Slow idle. Never when engine was turning fast or while driving.
It went away when the idle was really smooth (after a full tune up) and seemed noisier on a hot slow idling engine.
My guess was that it was crank shaft thrust of some sort banging something against something else when the engine wasn’t idling smooth.

From experience.... Check to see if there is any slack in the crank pulley. You'll have to remove a couple belts, but it could save you some $$.... My '87 was making the same noise you describe..... Thought it was a lower end clunk but only at idle. Turns out to be the end of the crankshaft where the pulley slides onto the keyway.... the keyway was reamed out big time... So the pulley would overrun the engine RPMs rhythmically and clunk each time exasperating the problem. I had 1/4 turn of slop. Unfortunately the only fix is to remove the crankshaft, have a machine shop weld the keyway shut and grind a new one. As in my case.... I went ahead with a complete rebuild Hopefully this isnt your issue.... But keep it in the back of your mind. Just for kicks.... I've heard of guys welding the crank pulley directly to the end of the crankshaft. Oh the humanity!

 

[Chris Cahill]

I would start with a good valve adjustment and checking for exhaust leaks. You said it was desmogged but did you remove the air rail? On my first 60 I had a terrible tick that I swore had to be the manifold gasket. I spent an entire day changing it and later discovered that it was just a crack in the air rail.