I have an Ingersoll GR 250 compressor with a 4-53 detroit engine.  Engine starts good runs good as any detroit does...However, when the compressor pumps up and the engine winds down ther is a loud clicking noise that is then intermittent at idle until the air is bled off and the engine loads up again.  Due to the noise of this machine it is dificult to determine where the nise is coming from.

Also looking for a manual for a Gyro-Flo compressor.