Thanks for the update. Never heard of that before. 

Kelley

To close this out, it was the transmission/forward clutch. Wild Child rebuilt the trans and diff, along with a bunch of other stuff, and it's running great now. https://www.facebook.com/photo?fbid=1070702361723188&set=pcb.1070702528389838

Let us know when/ if you have details.

Thanks,

Kelley 

quick update that the noise turned out to be coming from the Diff. Thanks all for your help and suggestions

Yes, thanks for the heads up. I just added to my next parts shipment 

I believe the MPI had the front mounted radiator.  The Japanese market never had the MPI, likely because they couldn't wedge in an air conditioner.

It's certainly possible that the problem is in the engine/drive train. I've seen several cases of the diff pin sliding out of place and carving away differential cover on Minis from this era. That probably squeals a bit but as far as I know no one noticed until the front wheels locked up permanently. The worst case sort of squeal.

Cheers,

Kelley

Would a 1995 SPI have a belt driven fan or a front-mounted rad with an electric fan??

My guess re motor mounts would be the upper and lower engine steadies. Though I think that problem might generate a single squeak when engine torque is applied. Maybe the main motor mounts are allowing the engine lump to shift enough that a driveshaft is rubbing, possibly on the exhaust or the frame tower opening. The unusual sound I hear is more of a fluttery noise - frequency seems to correlate with engine rpm.

Another guess might be a burnt or stuck exhaust valve making a louder noise transmitted through a tubular (not cast iron) header pipe wall. 

I think you're saying that you're replacing the engine mounts. Are you also replacing the upper and lower engine steady rubber bushings? The subframes are also rubber mounted which can cause no end of weirdness. Probably not the squealing though. 

Kelley

Thanks, the engine does move quite a bit (replacement mounts just arrived). I'll see if I can grab a video of the engine compartment under power braking

Check the clearance between the fan and the fan shroud. It could be the fan belt even if it only seems to happen when accelerating. Also check how much the engine moves when you accelerate. The engine bay on the Japanese spec cars is pretty solidly packed so anything out place can cause strange noises.

Kelley

Thanks again. Sounds like there's a good chance the engine has to come out 

OK, that recording is better. 

I don't Know the sound - I'm not an engine builder. I imagine a wrist pin out of place would be making noise all the time.

I wonder if another possibility would be the timing chain: the tensioner might  be worn out?

Or maybe something in the drive  train such as drop gears (from clutch down to transmission), something in the transmission or in a driveshaft (pot joint or CV jpint) - something making noise under load.

I think I was better able to capture the sound in this video, especially toward the end

https://youtube.com/shorts/xDyKd7qT8Sk

Thank you! I will give that a try and report back. I'll also see if I can get some better quality audio. 

I listened to both clips with my volume all the way up - could not hear a "squeal." I do hear more of a flutter on acceleration that sounds to me like an exhaust leak near the manifold. I may be away off on this, but to check for exhaust leak, have the bonnet open and the engine idling, cold at first test and then warmed up. While you or someone familiar with cars and has decent hearing, listen to the engine while someone else puts a restriction at the tailpipe. This increase in back-pressure will cause an exhaust leak to be evident. Use a length of hose like a stethoscope to listen around the engine to try and pinpoint where suspicious noises are coming from. If your exhaust system is leakproof, the engine should bog down and possibly even stall (though with fuel injection, the engine management system may compensate).

Another more remote possibility is that a squeal may come from a disk brake dust shield on acceleration or cornering if it touches a rotating disk. If it is close to the disk, the very slight deflection of the hub bearings is sometimes enough to let it rub. 

Hello All,

Trying to troubleshoot an engine squeal in a 1995 Japanese SPI automatic. I originally assumed it was a fan belt, but I was told it's coming from inside the engine (possibly a wrist pin or another loose component requiring an engine rebuild). It's not audible at idle from inside the car and only happens when in gear and under acceleration. Not audible when I rev the engine in neural or park. Curious if anyone has experienced this in the past.  thanks!

https://youtube.com/shorts/fWRRsxivAZE

https://youtube.com/shorts/1ETcUro72Fk