When the motor is warmed up and I rev it to a high RPM like 4000-4500, coolant will shoot out from some unknown location. It's NOT a leak anywhere, it's like a cup of coolant. It looks like it might be coming from the water pump intake, but I dont see how since the snout has a lip and it has a hose clamp that is pretty tight.

None of the hoses are leaking or broken, all brand new (this is brand new build btw). It's only at high rpm and it's only like a cup or so, but it doesnt do it all the time. It happened once before, we tried to recreate the problem, but it wouldnt go.

WTF is going on?

 

unless you can rev it, and have it spray up while watching it (huh, not a bright idea actually...) you'll never really know.

you could hook up a coolant tester, basically a handpump pressurizer, pressurize the system and see where/if it leaks.

There's a hole in the top of the water pump, that'll leak when the bearings go I think... is it the old water pump on the new motor?
water pumps are pretty cheap.

 

My bet's on the waterpump. I've had those things go out on several different cars when they get old just by replacing the serpentine belt -- too much tension for the old pump. Could also be a bad radiator car, but I doubt it. I think they're 16lb caps. Could also be some other bizarre thing such as the heater valve is cracked or something like that.

 

all parts are brand new. I have new rad cap that is high pressure, it has one of those pressure relief tabs and the coolant overflow is also hooked up. No heater core, goes from rad to pump to rad again, no other components in the system.

 

Head plug or coolant sensor/fan switch not installed or all the way?

 

there is no fan sensor / switch as of yet, while running the motor, I just give power to the fan by hooking it up to the bat. I havent gotten my dc controller yet.

Also, it's coming from the front of the motor, because it gets all over the front and on both sides, but mostly it gets on the pass side. this is why it's thought to be the water pump hose.

It doesnt leak anywhere else at any temp or RPM, only when it's warm and i rev it high. it's also not a consistant leak. it just sprays out then stops.

 

This happened to me, but seemingly less severe.

I had bad hose clamps and so my radiator hoses would start to pee out coolant when it was revved (i dont know why it wouldnt do it at lower RPMs). I just got my safety glasses on, turned the car on and throttled the carb and found out where it was. 5 second test and a 10 minute fix .

Hopefully yours will be that easy.

 

Obviously it is a leak. Get a friend to watch the motor when you rev it. Or work the throttle by hand as stated above. And don't forget your safety glasses.

 

And be friggin careful if the coolant is warm. Third degree burns are very likely.