Water Pump whistle??

[volavet]

Just got Opti and Water pump replaced. Now I hear a whistle like sound as I accelerate and or rev. Not really noticeable at idle. Is this normal for an LT4? My old pump did not do it, but it had been weeping for a few years, so I thought maybe the fact that it was going bad had something to do with the lack of distinct whistling sound. I vauguely remember a distinct whistle sound when I first bought the car that was diff. from my 92 with the LT1. Any comments would be welcome as I am scheduled to have them rip out the new pump and put in a new-new pump since it appears the one they put in may be defective. However, I dont want them to do all that work if its not abnormal. Also, all hoses have been checked, belt, alternator, pulleys, and there no vaccum leaks. It has been isolated to the water pump. Any help would be greatly appreciated.

 

[volavet]

bump.

 

[Vettelt193]

It could be just breaking in... but, a whistle is abnormal from my experience. I'm really not sure what to tell ya; sounds are all a subjective thing, like how loud the sound is. if it is a very quiet noise, then it could be normal.... very loud, probably not

 

[volavet]

Its not horrible, but it is noticeable when walking up to the car if Im reving slowly. Its kind of a low pitched whistle. You mentioned the pump "breaking in" I never heard of a pump needing to break in? Is that normal? I suppose I could give it a few weeks. It definitely did not do it with the original pump I just had replaced though. The sound was the first thing I heard when I started the car from the shop and noticed it was different. I think it may be a bad pump, but I also dont want them to rip everything apart to replace the pump if its normal. I need to find a local with an LT4 to listen to. Thanks for the reply

 

[Tuna]

Whistling water pumps or OptiSparks are not normal.

I did not have any such annoyance when my LT1 was upgraded back in 2003 which included a new water pump and LT4 OptiSpark.

Just brain storming: Check the coolant level, bleed the system one more time and make sure all the air is out of the system.

 

[volavet]

Thanks for the reply. I think it probably is a bad pump, but I wanted to make sure I was'nt missing something before they tear apart the engine again.

 

[Vettelt193]

Its not horrible, but it is noticeable when walking up to the car if Im reving slowly. Its kind of a low pitched whistle. You mentioned the pump "breaking in" I never heard of a pump needing to break in? Is that normal? I suppose I could give it a few weeks. It definitely did not do it with the original pump I just had replaced though. The sound was the first thing I heard when I started the car from the shop and noticed it was different. I think it may be a bad pump, but I also dont want them to rip everything apart to replace the pump if its normal. I need to find a local with an LT4 to listen to. Thanks for the reply

they don't necessarily break-in by the manual, but anything like that will break-in / wear-in to an extent.

what I was really trying to say the noise is subjective... some people can hear things others can't. I can actually hear TV sets that are on (not the sound the speakers make, but the TV makes a sound), where most people I ask can't.

 

[volavet]

Thanks for the reply. I guess I will wait and see, I need to find a local dealer with an LT4 and have them start it up to see if it sounds the same. As I said, it is very noticeable if your looking for it and the shop went from saying it was normal to it sounds like it may be a bad pump. Its like an air rushing sound as you rev, low tone whistle, not overbearing, but as I said, it definitely was not on the orig. pump. Next time you turn yours over, listen to see if you hear a small whine or whistle noise and you go up and down with light throttle.

 

[stgry1]

Volavet, to chime in on this conversation.....are you sure that the whining noise you hear IS NOT coming from a vacuum line leaking near the WP?? There are a few in there that maybe be clogged, leaking, etc. If that's NOT the case, my next thought would be the pump bearing. Once you replace the pump and DO NOT run coolant thru the hoses prior to starting, the pump will start dry and NOT receive any cooling and/or lubrication until the thermostat opens. At that point the pump is extremely hot and damage is occuring. It is possible the tech was unaware of this scenario and it might have caused damage. Let us know

 

[volavet]

Thanks for that great info. I will ask. However, this shop is extremely prof. and all they work on is vettes, so I dont think they would make that kind of mistake, but I will ask. I will let you know what happens.

 

[volavet]

bump

 

[Paul G]

Sounds more like a vacuum leak to me. Has the shop had a chance to diagnose the sound?

 

[volavet]

They replaced the new Opti and new water pump to see if one of the new parts was defective, and it still has the whistle. Cannot find a vaccum leak so far.

 

[Paul G]

My CE has a whistle while the engine is running. I never put much thought in to. I think it is coming from the pump that is mounted under the left head light. When the engine is shut off it kind of exhales also. The car runs fine so I didnt really pay much attention to it. See if your whistle is coming from that pump.

 

[volavet]

I'll check it out. Although I never heard it before i had the work done, and I know as, most of you do, every creak, wrattle, and sound from my vette, so it was very noticeable when I picked it up from the shop.