View Full Version : Raw water pump vibration
07-31-2013, 04:45 PM
Good afternoon all. I am new to the group but have been lurking in the shadows for a little while learning as much as I can from you all. I just got done rebuilding my LT1 raw water pump (seal, impeller, bearings). After I installed it, I have alot of vibration, almost shaking, in it now. I am not quite sure if it was there before or not. I had MAJOR alternater issues up til now.(Got that fixed FINALLY!!!!:D) I don't think this is normal engine vibration as I can start to feel it at idle. You cannot feel it at all as the RPM's rise just a bit. Runs great and stays nice and cool all day. I had the shaking engine thing before, but that always seemed to be right before the alternator belt decided it didn't want to play anymore and jump off the pulley. Are the mounting holes off set so they need to be lined up a certain way to eliminate any shaking? Thanks in advance for any help!
07-31-2013, 06:40 PM
Im not sure how much yours is moving, and I'm not sure if there is any possible adjustment or not. I have a '96 and it does move a little too. At first I thought it was a bad impeller, but after replacing it, I can kind of see why it is going to move a bit. The impeller blades are constantly loading and un loading as the pump spins. This is bound to create some movement or slight vibration. We will see what others say soon.
07-31-2013, 10:41 PM
I spoke too soon on how good and cool it ran. I took it out tonight and it overheated in about 15 minutes. limped it back in. starting to tear back into it. hopefully I can find a quick fix. It is very frustrating to see the disappointment in my wife and kids each time we go out and something happens.(seems about every time):mad::(
07-31-2013, 11:38 PM
I hope you get it fixed. Most on here love the LT1 after they got the initial cooling issue fixed. I assume you know about that? If not, search on here for it, there are a lot of threads. Bottom line, there needs to be a cross over tube between the heads on the front of the engine or they run hot and over heat. There is a cheap kit from a dealer to fix it.
08-01-2013, 01:05 AM
JaketheBT- Thanks for the info. Will check the threads and make sure I am good on the cooling system. Tonight was the first time it got over 150-160 degrees. Figured I'd start at the last thing I fixed and work my way up from there. Had water in hoses up to the thermostat. Popped it open and found a stuck closed thermostat. Gonna clean up the parts add a fresh coat of paint, new thermostat, and start over. On to the circ pump next. I am really hoping the t-stat will fix this one. I gotta say I am getting much faster at these front end dismantles.:rolleyes:
08-02-2013, 05:44 PM
Is it possible to install the pump off-center? That would cause the pump to bounce around quite a bit. If so, what would be the best way to center it up?
08-02-2013, 05:56 PM
Was the water pump you rebuilt the origional one? I believe some have a specific bolt configuration. Any pictures?
08-02-2013, 07:28 PM
Yeah it was the original. I put new impeller, seal, & bearings. I will try to get pics up in a couple of days.