Loud Chirping from engine 1982 xj650 - video provided

Hello, After recently having the engine block cleaned, head and valve cover gaskets changed, and valves adjusted I noticed a very loud chirping noise coming from the engine. My current guess is either a head gasket leak or possibly the camshaft not receiving enough lubricant. It seems that the sound is coming from cylinder number 3, which also happens to have the coolest exhaust header, when compared to the other three pipes.

I have also noticed that on hard acceleration the chirping stops, but returns again immediately after letting off the gas, It is constant throughout idle as well as during riding.

Any other possible suggestions as to what the sound might be an indication of?

Here are two videos that show the sound the bike is making:

 

Not sure, but it sounds to me like a leaking head gasket. Have you checked compression?

 

If you had a cable-driven tach I'd say that it might be the cable, but you don't, so........head gasket. Who's gasket kit did you use? Lately there have been several members who got kits with cam-chain tunnel gaskets that were too thick, leading to head gasket leaks at #3, or #4 (or both).

 

Vacuum leaks can make a chirping sound..........

 

Can it be valve shims?

 

Feel around the head with it running to see if you feel air blowing out. Watch those head pipes so you don't get burn't.

 

I'm going to check compression on Wednesday and report back with the numbers. I was debating valve shims, two were out of spec and were replaced prior to re assembling the engine. I'll also check cam chain tension and see if that might be it.

 

I'll have to ask my friend who he purchases the gasket from as I am helping him with the bike and it is currently at his place.

 

Not likely. They'd be the very last thing I'd suspect.

 

I'd say either an exhaust leak (check the collars), or a head gasket leak......

 

I had the same chirping sound on one of my XJ1100, it would go away at higher RPMs. It had an after market exhaust, changed the exhaust gaskets... still there (apparently I could not get it to tighten down properly). I could never feel the air coming out. Put a stock exhaust on and the problem went away (even using the same gaskets).

I would lean to it being an exhaust leak 0r a vacuum leak. I one time I had as head gasket leak (wrong setting on my torque wrench ) I could not hear it but I had loss of power and was able to feel the air being blown out.

 

Well I figured before taking off the valve cover I should take the exhaust off to make sure it wasn't a leaky gasket, however although it is much louder, the squeaking was still there.

I just finished checking all the valve clearances and everything is in spec. I am debating that the new shims might be causing it to chirp. I haven't been able to find any had gasket leak, I should also note that the bike is running quite well, I am not noticing any loss of power, however I haven't opened it up on the highway to see, but gears 1-3 seem to be fine.

 

I doubt a shim is doing that

 

It almost sounds like bearing failing, but not a plain bearing....a ball bearing, or maybe a shaft seal that's hardened.
Take a length of vacuum hose (any hose really) and stick one end in your ear. Probe around with the other end until you can pinpoint where the chirp is coming from.

 

Also, from others' past experience here, double-check your manifold boots where they bolt to the head----

 

The manifold boots are in great condition. I recently repaired all four, and re-installed them with brand new gaskets before checking for leaks and finding none. My guess is the actual camshaft. It sounds as though its coming from the exhaust cam.

Are there any guides on dismantling cams to replace worn seals or bearings? Am I better off just buying new camshafts?

Also is there a possibility that the cam chain tensioner over tensioned the chain and it is now causing it to chirp?

 

(Are there any guides on dismantling cams to replace worn seals or bearings? Am I better off just buying new camshafts?)

You can't just change the cam bearings as they're integrated with the head. Of cause it can be done but then you will have to machine it. It's probably better to look for a new head if that should be the case.

 

Uh, seems to be a common thought here-----

Does that mean you're NOT gonna double-check your gasket work? Whatever......

just seems to me, that it would be easier/better/cheaper to go back and double-check them all. I'd rather find that, then tear apart the engine, only to find out that's what it was in the first place. But,that's just me.

That said......

Double-check that your plugs are in correctly, if a plug is not tight, or the crush washer is not sealing, that can happen, too.......

If you do a forums search for : chirp, squeak, loud noise, etc....... You'll find that almost every single one of them turned out to be either an intake boot leak (think kissing sound--vacuum leak) or an exhaust leak ( think farting squeak)

Kissing - vacuum
Farting - exhaust

Only a couple times have there been other causes.

My bet is still on a vacuum or exhaust leak.

Dave Fox

 

I would put the exhaust system on then see if the noise goes away. It might the valves opening and closing.

 

Vacuum hose.
Stethoscope.
Listen.
Pinpoint the source of the noise.
Quit jumping to conclusions. Cam bearing failure does not make a chirping noise (in my experience).

 

Thank you for all the help guys. After going back to check the intake boots upon the advice of you guys, I discovered an air leak in intake boot #3. After sealing it up and re starting the bike I can happily say that the bike is now running with no chirping whatsoever.

 

Glad to hear