MTFCA Forum

I need some help diagnosing my engine noise. Or at least I think it's engine noise. When under load, if I throttle up, it sounds like a bird chirping coming from the engine area. If I back the throttle off, the chirp goes away. Throttle back up and it comes back. It is very consistant with what sounds like every 4th cylinder fire. It has me.baffled, and I don't have anyone that knows how to drive the car so I can climb around and get a better idea where rhe sound is coming from.

Has anyone else noticed a similar sound and figured out how to remedy it?

Is there a way to post videos on the forum?

Exhaust leak??

Does it do it sitting still or just in motion? I had what sounded like a bearing squeeling or a fan belt slipping. Only in motion and about 20 to 30 mph. Drove me nuts. I finally found the radiator shell was rubbing on the hood shelf. Are the sparkplugs tight? Check for sheetmetal rubbing somewhere.

jab35 wrote: ↑

Mon Jun 08, 2020 10:31 pm

Exhaust leak??

The gasket is shot on cyl 4. I am waiting for a new manifold to arrive then I will take care of that issue. I can see an exhaust leak making a noise like this but to me it would be strange for it to only make the noise under load.

Dallas Landers wrote: ↑

Mon Jun 08, 2020 10:37 pm

Does it do it sitting still or just in motion? I had what sounded like a bearing squeeling or a fan belt slipping. Only in motion and about 20 to 30 mph. Drove me nuts. I finally found the radiator shell was rubbing on the hood shelf. Are the sparkplugs tight? Check for sheetmetal rubbing somewhere.

Only in motion and only under load. I've put my hand and foot everywhere I can reach while driving trying to see if it's a body noise. To no avail. Sparkplugs are tight.

I had that exact problem years back. It was a leaking head gasket. I got lucky and the noise went away after re-torquing the head. You might have to change the head gasket.

"Bird chirping" under throttle is an intake leak... it's a vacuum whistle. Check your gaskets, and I bet you will find that's where your issue lies... either your intake gland rings or your head gasket... BTDT on way more than a T.

I had the same issue that Chris described. Changed the head gasket and that solved the issue.

Had the same problem at one time, took off the compression whistle! Sorry, couldn't help myself.

My first thought was a loose spark plug or possibly two piece plug not screwed together tight enough. Then you have one of those d**m explosion whistles that I hate so much!

I’ve experienced a chirp like that twice on T’s I’ve worked on and both times it was a head gasket leak to the outside from Cyl #4. I suppose it could come from any cylinder. You will likely have pretty cruddy rust out around the water passage and/or a warped head that needs to be cut. Less possible is that the deck of the block would be warped, but if it is, then it should get cut. If you re-used the head gasket, then maybe thats the only issue.

It probably wouldn’t be an intake or vacuum leak if it happens when opening the throttle. Vacuum is higher going down hill at closed throttle or on flat straightaways at constant speed.

The first time I had a "chirp" was 68 years ago when I had my first car. A 1928 Model A. I had removed and replaced the cylinder head. I tightened it down and went for a drive. I had a "chirp". I had not re-torqued the head after the engine warmed up. Had to replace the gasket again and tighten it correctly.

Many years later with my first T, I noticed a "chirp" when I pulled a hill. This time it was around the spark plugs. A clue would be some oil or fuel mixture in the dips in the head around the plugs. In this case, I wrapped a bit of aluminum foil around the plugs and re-installed. This cured the problem.

Anyway, it is a compression or exhaust leak and you can find it if you try.
Norm

Head gasket.

mine does that constantly. After a lot of searching around the engine I finally figured out it is the thimble on the radiator shell on the right side. It apparently strikes a resonance with the engine vibration at higher RPMs. I messed with it for a while and finally just left it alone.

Just something else to check.

This reminds me of an experience I had in New Zealand. I was driving a loaned model T on a tour, for the first time, and she performed valiantly up a long pull before we started down hill. A few seconds after cresting the rise I heard an unearthly squeal and instantly killed the motor and pulled over. The noise was STILL there! We'd entered a wooded secton and the noise was 473 million cicadas all working in unison!

Allan from down under.

Another noise I get on my 26 is the choke rod vibrating against the dash panel. Try holding it when driving and see if the noise stops.
Norm

I just got notification that my new exhaust manifold is shipping. So I will be replacing the entire exhaust, plus redoing the intake gaskets.
I just recently replaced the head gasket, and all bolts after chasing all the bolt holes so I'm pretty sure that's not the issue.
I have felt and pushed on everything I can reach while driving to stop the noise.

I have to agree with Adam. I had the same chirping problem. Head gasket leak at the rear cornier of #4 due to corrosion on the block around the little water hole. Changed head gaskets multiple times and tried to "repair" the corrosion with JB Weld. Worked only temporarily. Finally had to tear the engine down to have the block surfaced. I hope you find your problem simpler to fix than that!

Head gasket.

"I just recently replaced the head gasket, and all bolts after chasing all the bolt holes so I'm pretty sure that's not the issue."

Did you re-torque the head bolts after a warm-up & cool down? If not....

I had the chirping problem some years ago. The chirping occurred under load when gradient climbing in top. Throttling back stopped the chirping.

It turned out to be a crack in the porcelain of a spark plug. Plug changed - chirp gone.

I also have a sharp chirping sound and have the impression it is depending on engine revs - it is not heard constantly.
Suspicious for me is the fan as it is the same sound when the fan hit the radiator years ago after the screw got loose (the one near the oil filler cap).
I can see blank metal on the slightly bent edge of one propeller so it might have contact with some metal (but definitely no sign on radiator fins).
Turning the fan manually does not show this but maybe with running engine the relative position of the propellers change by the power of the air that drives through ?

Thanks to some posts here I will now also check the choke wire and radiator shell.