gt380 chirp

[smokingbanana90]

Hello, recently I got my 380 working again and Ive been driving but its back in the shop again because the right side cylinder doesnt like to fire and when it does it pops and chirps especially when its cold . It has good spark and the other cylinders work great. What could be any causes of this right cylinder just quitting like that? Thanks!!

[Vintageman]

Did you have the points changed not too long ago? If so they may be pitted due to a bad condenser.

Pop sounds like points to me ("Chirp" like a bird?, check timing maybe too far advanced)

Plug cap may be bad too

[yeadon_m]

'Chirup' sounds might be metal on metal? maybe check carefully the lubrication system in case oil is not being injected into the right side upper cylinder.
Mike

[Suzukidave]

If the points cam felt isnt lubed i have heard before the rubbing blocks on the points make a chirping sound as they contact the cam .

[Coyote]

There is one pissed off bird living in your right pipe! Seriously, pull the baffle and check the inner plate (about a foot down in there). It could be coming loose and squeaking. While you're at it, see if the right side picks up without the baffle in place. Could be a clog.

[Cliff]

Check for a head gasket leak on that cylinder.

[jeff kushner]

Cliff's right, head gasket leak......



jeff

[yeadon_m]

Good spot, top marks to Cliff!

[smokingbanana90]

Thanks guys! When I get back into the shop I will check all those things and get to the bottom of it!

[vanillaice]

Would compression test show up bad cylinder gasket?

[Vintageman]

Cliff is most likely correct about head gasket leak for chirp (nice call!). I may have used a polite “fart” sound

But I suspect more maybe ?(need more info to be sure)

If head gasket was leaking, bad enough to stop firing or power significantly from cyl it would sound more steady and loud. I don't think you would called it a just a pop and chirp only when cold. still does run that cyl when warm and no more chirping???

for example if the engine was not firing consitently, building up unspent fuel and then ignited the explosion would be very strong and maybe at the wrong time. This can stress the head more than normal causing it to bow up (only 4 bolts per head that design) and some combustion gas would leak by (chirp/pop).

So yes you probably have a bad head gasket, warped head, eroded Aluminum and/or, loose head bolts. But sound slike not firing as it should?

So if head leaking it should fixed, but a leak would have to be bad and steady to affect it that bad?

If it leaks significantly you will hear and will show up on a compression test

[tz375]

Would compression test show up bad cylinder gasket?

The answer to that is "perhaps". It might show up on a compression test, but there's no guarantee that it will. Do one anyway to see.

Fortunately the head comes off really easily and as long as the barrel surfaces are OK it's an easy fix.

[mike1161]

Hmm, very interesting. I've noticed a chirping sound from my T350 also, sometime after the rebuild. Funny, though, I did re-torque all the head bolts to spec a 2nd time after running for maybe 100 miles or so.
But I'm going to check them again, because otherwise not sure where that chirping comes from. I does seem to happen just when I rev it a bit. For example, I don't hear it a steady speed. I will report back what I find out.

[pearljam724]

If the points cam felt isnt lubed i have heard before the rubbing blocks on the points make a chirping sound as they contact the cam .

Agree on the chirp noise. Points need addressed or it's out of time.