Pontiac Engine Noise???

I just built a 77 pontiac 400. After i started it, it started whining really loud. The noise starts around 800-1000 rpm, increases in pitch as the rpm increases, and is louder than the engine itself. it seems to be coming from the upper half of the engine and towards the rear. It's lower in pitch than a bearing screach. It's very hard to describe this, but it's also been very tough to locate. My guess is that it is the distributor, something acting like a reed in the carb, or possibly the transmission?? any suggestions, experience, or ideas would be appreciated!!

Start by using starting fluid, spraying it around the base of the carb. If the engine revs up, you found a vacuum leak. We've seen this many times.

If you still believe it to be in the distributor (not out of the question), find another one and swap it. Noise goes away? Problem found...

Jim

Thanks!!!

Distributor was bad. Got it fixed now

Cool...

Jim

I'm having a bad day to say the least. I hope it isn't serious, but my oil pressure was acting up last night. I broke the cam in, and pressure was fine. I drove the car about 5 miles and the pressure was fine. I changed the oil last night, and after the engine got to warm, pressure started dropping. When the engine was hot, the pressure dropped to about twenty lbs at idle, but was fluctuating. It increased w/rpm, but was still up and down. I changed the filter and added 6 quarts,,,, could it be frothing on me?

Stephen,

The oil pressure will normally drop to 20-30 lbs. at a HOT idle (200 or so). Rule of "thumb" is 10 lbs. of pressure per 1,000 RPM. If it jumps up to 60 at about 2,000 RPM, everything is okay.

What brand and weight of oil? "Frothing" is rare with modern oils. Is the windage tray installed?

Jim