I just got this 85 T/A and I've been working on getting it on the road; brakes, belts, etc. Since I haven't had it inspected yet my driving has been restricted to around my neighborhood a few times. Anyway, the last 2 times I drove it around I've encountered a strange flapping noise.

The noise is directly related to engine rpm and occurs in any gear (including park and neutral) and while the car is moving or stationary. It only occurs sometimes, but when it does it sounds sorta like a piece of paper being held into a fan.

Usually I start the car and all is normal, no noise while the car idles. If I rev gently it's fine, but as soon as I rev it a little higher the noise begins. Once it begins it remains, even if I drop the rpm, however if I rev it up and down a few times it usually goes away.

It sounds like it's coming from the transmission tunnel area, I looked underneath and I cannot see anything out of the ordinary. The flywheel cover was missing when I got the car, I bought a replacement but haven't installed it yet, so I can see the flywheel spinning and I don't see anything getting caught or rubbing on it, although it's spinning so fast is sorta hard to see.

I also thought maybe it was a vacuum line flapping against the hood, but I looked for that as well and didn't see anything either.

Any thoughts? It's quiet loud and annoying in the car when it is making this sound.

 

Wow, that's a weird one. Unless you happen to spot the problem visually, I'd start by narrowing down whether it's an engine issue or a transmission issue.

Unbolt the converter from the flexplate and push the converter back (it'll move back about 3/8"). Start the engine again and do the usual revving thing.

If the problem remains, it's somewhere from the flexplate forward. If it doesn't, it's a converter/transmission issue.

 

AIR system intact?

 

Thanks Damon. I jacked the car up and got right underneath, still can see ****, but it definitely sounds like it's coming from behind the motor towards the transmission area. I have a lift in the garage so I'd like to get it up on there so I can have a really good look, but I have another project on there, so this might have to wait a few weeks. What you're suggesting would be much easier on the lift though.

Naf, if you're refering to the smog/pollution system, then I think the answer is not it's not intact. There's no air pump on the car & being a Canadian car I am not sure if it ever had an air pump - Canadian laws might not have been that tight back in 85.

Oddly enough...when I started it yesterday afternoon the noise was completely gone. Revving up and down everything sounded normal...go figure.

 

So I was able to dig up two old threads on this:
https://www.thirdgen.org/forums/tech...nd-my-car.html

https://www.thirdgen.org/forums/tran...nsmission.html

Issues sound exactly the same as mine. The first thread suggests that the cause was loose torque converter bolts and the second thread suggests that the starter might have been misaligned.

I've like to check both of those items, but I am not really sure how/what I should be checking. Can anyone provide some more details or bettery yet a photo of the bolts I should check?

Sorry to sound like such a noob, I am not really used to working on automatics.

 

Converter bolts can be accessed by removing the black, plastic inspection cover between the motor and trans. It is attached to the Trans with four 10mm self tapping screws.

The converter can then be seen. It is attached to the flex plate with three 13mm (?) converter bolts. The motor will have to be turned to get to all three.

Remove the bolts (or tighten if loose). Once removed, the converter can be slid back towards the Trans and the engine run without the Trans connected.

 

Thanks, that's exactly what I needed. If I do remove the bolts and slide the converter back, once I've done my check is reconnecting it as simple as pulling it forward again and reinstalling the bolts?

 

Yes.