1989 454 (7.4) no water

[CptBacardi]

Thanks Viper. I’m 100% positive the hoses are correct. I’m weird like that. I did replace both o-rings and the wear plate. The direction of the impeller is also correct. It’s almost like something might be clogged? Does this engine have a water pump like a car? I don’t understand what else to check?

[CptBacardi]

[bud37]

I am guessing you did the other engine and it is fine so this may be just a little thing..Did the old impeller come out with all it's pieces?.....did you match the new one to be sure it is the correct part....I know the hoses are correct but did you disturb them.
Those little pumps pull hard and even a minute air leak will short circuit the pump on the suction side....check your hose connection , if it is old cut some off and reconnect to be sure....if the new impeller has been run without pumping water for even a short while then it will need replacing.

I have had that little suction air leak before and that is just how it appears.

[CptBacardi]

Thank you. Yes the old impeller actually looked perfectly fine and came out in one brand new looking piece. The new impeller is the correct part and size. I’ll check the hose again and cut a little off. Hopefully that’s all it is. I’m understanding from all of y’all’s feedback that there really is nothing else that moves water through the engine but this impeller.

[Viper]

There is a circ pump like a car. Did you inspect the pump housing for wear? Is it a metal pump housing or the newer plastic type? If it's scored, it needs to be replaced.

Is this raw water or fresh water (engine coolant) cooled? A clogged oil cooler will restrict flow, so will a clogged heat exchanger if applicable.

Do you have sea strainers and are they clear? I assume the seacock is open? Do you have Walter V-drives separate from the engines?

Was she pumping fine before the impeller change?

[CptBacardi]

It’s a plastic housing and it appeared ok. It’s raw water to the inlet side, and that hose was flowing water just fine. No coolant exchanger or anything. Just raw water. There is a part on the engine that looks like a water pump on a car, does it not do anything?

[km1125]

QR_BBPOST It’s a plastic housing and it appeared ok. It’s raw water to the inlet side, and that hose was flowing water just fine. No coolant exchanger or anything. Just raw water. There is a part on the engine that looks like a water pump on a car, does it not do anything?

As I noted in post #2...
There is a separate pump that circulates water around the engine, but that has nothing to do with the raw water coming in or going out.

If you really ran that impeller up to 4000 rpm while dry you should probably replace it again... or at the VERY least pull it out and check it out. Even with a little soap in there that just works for the first few hundred rpm. If I had to take the hoses off to get to the impeller I try and fill them as much as possible before I reconnect them. If water's not available, I just use some PG antifreeze because it's pretty slippery too.

[CptBacardi]

I’m kidding, I only bumped the rpm from idle to maybe 2000 a few times. I left the inlet hose open and gushing water when I reinstalled it. Made triple sure it wasn’t leaking once tightened up. I did use a wrench and not a flat head screw driver. Wasn’t dripping. Thanks for y’all’s help!

[bud37]

Ah the plastic housing pumps.......there is a well advised kit that comes with a new housing . The old housings wear and can be cracked when tightening the bolts......be careful there as the crack can be very difficult to spot.....may not leak water but will suck air.

I used to clean the casting flash from around where the washers were seated.

[Viper]

All the above applies. The pump doesn't have very far to draw water though as the waterline isn't that far from the pump, your intake hose will automatically fill to that point by itself. Chopping the throttle helps the pump prime but it has to be a chopping action, not simply running at higher rpm. To confirm if she's actually pumping, follow the hose from the outlet side of the pump, through the oil cooler, and to the engine, disconnect the hose at the engine and run her. You should get water shooting out when you start the engine. You can also try pulling one of the lines at the T-start housing. You never answered my question about whether this is a V-drive application with a Walter drive.

If everything checks out, I'll take this in a different direction; are you sure she isn't pumping water out the exhaust? Does your particular build run the exhaust discharge through a hollow swim platform?