Noise in the motor. SOMEWHERE!!!

I've got a 96 GMC 2500HD with a 7.4L.(210,000 miles and counting) I recently developed a noise in the motor I can't figure out. It's sort of a deep chirping sound that changes with the engine speed. I've unhooked the Torque converter and Serpentine belt but the noise remained! I put rocker studs in so I could adjust the rockers. No help! Then I tried a new oil pump, (Pressure was good but I wasn't getting much oil to the rockers!) After the truck sat for two days waiting for parts. I put the pump in. It was quiet for a minute or two then the noise came back. I've had a dozen ideas on what it could be. But If I spend more money on Ideas I'll have to listen to my wifes grumbling. (Not that I blame her. I wasn't pleased with the outcome either!) So Any ideas would be greatly appreciated!

Reply to
Daveman
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My 350 engine did the same. Started with quiet chirping but changed to rattling and knocking in a few weeks time. Turned out to be a crankshaft bearing going iffy. Resulted in massive metal particles in the oil and oilfilter and a wrecked engine. Next time I listen to any warnings an engine makes.

Timo

Daveman wrote:

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Timo Wildschut

Reply to
Daveman

Well I think I found the culprit. The Oil pump was definitely going. But I never thought to recheck the distributor. Turns out the gear on the base was about 1/3 chewed up. From what I was told the cam should be OK. They supposibly made the gear the weaker link. Will let you know for certain how it works out once the gear comes in and I get it back together. Wish I would have though of it earlier though. Then the truck would be done now instead of waiting till the weekend!!!

Reply to
Daveman

Well the gear was definitely bad. But two minutes after running it with the new distributor. (Nobody had the gear in stock but a new distributor was on $16 more!) the noise came back. Since the gear was so chewed up I'm guessing the cam took some damage. But for the $890 worth of parts. I may be looking for another motor with less miles instead! Does anyone know if you can bolt a small block chevy to a

4L80E transmission?
Reply to
Daveman

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