18 erude no water pumping at idle

[brokeboater]

cant figure this out. changed out impeller while i had the l/u apart. after i start it up at a high idle she pumps water pretty good. after decreasing to normal idle water stops pumping. water pump is submerged in a barrell of water. there was not a gasket between the w/p housing and the plate or the between the plate and l/u case. should there be? what could be causing no pumping at idle? thanks as always.

 

[OBJ]

Re: 18 erude no water pumping at idle

If yer looking at the water discharge from the exhaust relief ports, there won't be much there at idle. As the engine warms and the t-stat opens, you may get a misty spray. If the engine is not overheating and is warming up, you should be good to go.

 

[brokeboater]

Re: 18 erude no water pumping at idle

got the thermostat out while i've been messing around with it. it is getting hot. it's very strange. i have even run it with the thermostat cover off the see if it's moving any water. plenty of water until i idle it back then it stops pumping.

 

[bubbakat]

Re: 18 erude no water pumping at idle

Impeller plate or cup or the rubber grommets are sucking air at idle. Had a six do this and the impeller plate was worn out. I replaced everything including all the grommets

 

[rodbolt]

Re: 18 erude no water pumping at idle

hello<br /> check carefully for corrosion build up in the corner of the plate pocket. if it holds the plate off just slightly you have your problem. did you buy a complete new kit or just an impeller?<br /> use a complete kit with housing and scrape the pocket area carefully.<br /> good luck and keep posting<br /> PS an impeller installed backwards will do the same thing