I posted a thread recently about a whining sound eminating from (within?) the 3.0 timing case on my 3.5 swap. The car has run perfectly from just after the swap, however, it began whining (a mechanical whine...NOT electrical) 5 or so days ago. Here is what I have done: replaced the new timing chain tensioner and water pump with other new Nissan parts...one at a time...no difference. I will say that the spring in the new tensioner was approximately 1/2 inch longer than on the original and required more effort to push down into the tensioner body. I swapped springs before installing the new tensioner to make sure it was the same length as it was for the first 118K. The 3.0 chain and sprockets where thoroughly inspected prior to the swap and were essentially in new condition. I also replaced the main tensioner guide with a new Nissan part. There is no oil burning (or leaking), plenty of oil inside the case (inspected through both the tensioner and water pump windows) and there isn't one single metal shaving to be found...anywhere. The car runs PERFECTLY, but it whines like a small supercharger from ~1,500 on up (can't hear it if you're at highway speed) and hasn't gotten any worse. At this point, I'm tempted just to drive the thing. The motor warranty was voided when the engine was disassembled and installed in a '97, so I'm on my own. Any ideas? Thx.

 

Are you manual? I'd say check the flywheel.

 

Thx, but the flywheel's at the opposite end of the engine...I'm certain that's not it. This noise stems (or seems to stem, anyway) from very near the water pump area. With a new pump, though, and no change, I'm stumped.

 

alt. or a/c?

 

could it be a bad idler pulley?

 

I forgot to mention when we talked the other night, I have a whine as well sounds like I have a supercharger. I had this whine before I did the swap, so I attribute it to the "gatorback" belt I installed. My wifes car got a similar belt and hers whines as well.

Did you install a new belt? It could very well be that or I would say its an accessory making some noise.

 

I installed new Nissan belts at the time of swap...same belts as b4...no noise 'til 1,500 miles into it. As for it being the alternator, A/C compressor, P/S pump or idler pulley...it can't be any of these things. I've run the car with all belts removed and it makes the same exact noise with only the crank pulley spinning. I've also replaced the idler pulley with new Nissan. Anyway, whatever it is, it's almost certainly coming from within the timing case. The strange thing is that it isn't getting any worse. It became louder during the first two days, then it stayed exactly the same. I drove the car nearly 100 miles today (as an experiment) and it ran perfectly. This is some strange sh$t.

 

is the crank pulley grinding on the timing case?

 

I honestly don't know...I'll check that. Since the noise began many miles after install, though, I doubt it. Thanks for the idea, though.