longbeach

Hi, recently purchased a 1979 450 SL.142kmiles. Runs fairly well and have been driving it frequently all summer. But,since day one it has had this intermittent annoying noise. It is kind of a whooo, more like a muffled alarm. It seems to be coming from the area under the air cleaner housing. Initially this would happen infrequently with light acceleration. Almost always it stopped when I let off the gas. But, it rarely did it when stopped. Last week it did it upon start up and I got a chance to hunt around. It seemed like the fuel pump was making some noise (although not as loud as up forward), and I thought maybe the noise somehow transferring harmonically up forward. So,replaced the fuel pump and filter and the noise did not go away, but it totally changed characteristics as far as when it will start and stop. So, I'm assuming this has something to do with fuel, but what I don't know? Anyone else had or heard of this happening. Any ideas??? Thanks

Arizona Mike

Whooo-whooo? I'd check for a trapped owl.