[fjm280z]

I have just recently started hearing a really load metal scratching noise coming from my 1976 280z L28. It is intermittant. no pattern noticable. I'm very concerned about it. no power loss. engine idles and performs fine.

I can't really make out specifically where its coming from, block head or valves. its very loud, screatching, like metal scraping metal. At first I thought it might be belts loose or slipping but they check out OK. Engine has about 170,000 miles on it.

Anyone had a similar noise? Any ideas on what this could be? Im tempted to pull the valve cover to see if there is any visables signs of damage or metal floating around in there.

Please help !!!!

 

[yo2001]

How about the water pump?

 

[john cross]

yes, that would sound real bad, and be nothing...

 

[fjm280z]

I haven't tested the water pump but I have checked to see if water movement in radiator and thru hoses and the coolant seems to be circulating. I dont see any signs of leakage from water pump area and temp guage seems to be showing normal operating temps no overheating.

 

[DrX]

I had a similar noise from my '79 280zx. Turned out it was the starter. It wasn't disengaging entirely and was interfering with the flywheel. It was very random, because sometimes the gear would disengage and sometimes it wouldn't, until one day it stuck and wouldn't disengage at all. Replaced the starter and bye-bye noise.

 

[johnh240]

I would be suspicious of the alternator. Bearing noise can come and go on it and be related to whether or not it is charging. Another possibility is the idler pulley for a/c if you have it. I believe the a/c activates when using defroster (double check me on that) and could be screeching when compressor activates.

 

[Ron Diederich]

replace the alternator
ron

 

[fjm280z]

Ron,

I think your dead on. Ichecked the alternator and after high rev & release the alternator pulley was wobbling in direct correlation to noise.

Good call man...

Thanks
Frank