I made 5 trips with my 96 Z28 yesterday, and on the first four, did not notice ANY problems. On the fifth, when I started the car, it immediately started making a strange noise from the engine compartment- a sort of whirring/whining/grinding that varied with engine speed, regardless of whether the car was in gear or not.

The car will heat up quickly (at idle in about 1 minute) to the point where the fans will come on, but I don't have any heat.

Car has a full radiator, and a full surge tank. I took of the radiator cap and the coolant was "warm", even though the temprature gague had just read 220*.

I have an occasional miss that has been there before, It's a bad wire I haven't changed yet. ( I can see it arc). No other performance problems.

There is no coolant leaking from the tell-tale on the water pump as far as I can tell.

My first thought was a bad water pump because of the noise and the overheating, but the waterpump was replaced last February. (Non-OEM, I know, but a new unit). Anything else it might be? I really don't want to replace the water pump, but I would rather deal with that than a spun bearing.

Thanks guys.

 

how 'tight' did the WP shaft seem before you installed it? when my WP went, the ball bearings around the rear shaft were all over the place, making the shaft loose and causing it to leak.

 

Not sure. I think I was able to spin it by hand without too much problem. I did notice it leaking from the front cover and it definitely sounds like a failed bearing somewhere.

 

when mine leaked, it leaked down the opti itself and caused buildup around the plugs going into the opti. i have no idea how it didn't go out, guess i was just lucky. have you had your front end jacked up so you could see if there may be a leak?

 

If its the waterpump lower your radiator fluid just a tad, open your cap, start the car, watch the flow. If there's no flow the fins in the wp are not turning. Im sure you checked your weep hole?

 

There's nothing leaking out of the weep hole.