I started getting a metal on metal noise earlier this week in my '95 VG30E. It's really bad at cold start up, then grows and lessens as I'm driving. I had the water pump replaced 4 months ago along with the timing belt. At the time I understood the guy to say that the timing belt drove the water pump.
To me it sounds like the impellers of the water pump rubbing, so I took it to the mechanic who replaced it. He agreed it sounded like it was coming from that area and said he wanted to loosen the belt and turn the water pump by hand. He loosened the belt that runs the fan and alternator, then started it and the noise was still there. He spun the fan and said the water pump was turning free. He thinks it's the idler pulley for the timing belt.
Does this sound right? Is it an external belt that drives the water pump, not the timing belt?
I'm just wondering if he's trying to get out of warranty work. I've had a lot of work done at this shop in the past and never had a problem before. The Nissan dealer is 30 miles away and not a good option.
Does the sound resemble a knocking sound or rubbing? I have a similar sound and thought it was the water pump but turned out to be a loose valve knocking. Your right the timing belt does not turn the water pump the fan belt does.
it should be fairly simple to loosen your accessory belts and check all your pulleys, idler and tensioner if its equiped with one. they should turn easily by hand with a smooth motion no clicking or grating sounds. another thing you can do is take the belts off the crank pulley and crank the car if you are still getting same noise with the belts off its not a pulley is inside the motor. don't let it run but a very short time as you have no water flow at this point just long enough to determine if you still get the noise or not. it could possibly be a spun bearing crank or cam which is a major repair. prolly just a pulley somewhere though and no to the best of my knowledge there has never been a timing belt driven waterpump. good luck
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Yeah, it ended up being the tensioner pulley for the timing belt. I wish we'd noticed that when the timing belt and water pump were being replaced. I need to quit doing electrical work and study to be a mechanic, hourly wage is much better.
He should have replaced the t-belt idler at the same time as the belt...it's standard practice.
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