Might need a new water pump on RB25...

[chixwithtrix]

I just finished up bleeding the lifters on my RB and started it up yesterday. Sounded great as far as the lifters went, very smooth idle and running BUT there was an odd tinking noise that started about 2 seconds after I first stared it. Pretty sure it was not in the head and it was coming from the passenger side front of the engine and the engine was in-time and running smooth.

My guesses were water pump or something to do with stuff under timing belt cover. I point specifically to the water pump after that because I could tighten and loosen the water pump/alt belt and the sound would change a bit. Also it looks like the pump's shaft is bent as the pulley goes around it rubs on the back of the timing belt cover (pulley is not bent). So does it sound like I have a culprit here?

Next question is - should I get a stock water pump or is there a better one available for high horsepower applications?

[Coolwhip]

so the pulley wobbles as in the bearing is shot on the shaft of the pump? When that fails there is a peep hole under the pulley on the housing of the water pump that will weep or start to leak water indicating your pump is bad.

If it's rubbing, make sure your lower cover is on properly as well as the pulley is installed correctly too.

It is also possible that your timing belt tensioner is making a whining noise in that area as well. Take a look at those parts and see what you are dealing with.

There are 2 commonly used pumps, the OEM replacement and the N1 Water Pump.

[chixwithtrix]

I'm going to take off the water/alt belt today and see if the sound is still there. I replaced the tensioner for the timing belt with an OEM one, but if the noise still happens w/o the water pump moving that is my next culprit.

I'll probably pick up the N1 pump from Enjuku or Phase2, is there anywhere else that sells it cheaper than $170?

[eh?]

Is your car a daily or a track car? If it's a daily I would get the factory pump and not the N1. Usually performance water pumps flow less at idle and considering how RB's love to over heat I'd want the one that flow more at low rpm than high.

[ANVIL]

check nismoparts.com their prices are real good. might as well pick up an idler too.

[chixwithtrix]

I just replaced the idler...although I have an extra new one in case it is the idler.

It will be a track only car so it will be in high RPMs a lot. I'm cool with getting a stock pump, but whatever is best is important to me.