ive noticed if ive run the car with the rad cap off that the water is like kinda foamy, at first i thought maybe some of the soap from when the block and all that was washed out,but ive drain/flushed and filled it 3 times since and its still doing it.
ive tried a cooling system pressure check and its not showing leaks.the only place i had a leak when i first started the car up was the lil hole on the bottom of the water pump,which now does not leak,could it be possible for it to be sucking in air from that hole were the seal is without leaking?

my other idea is the heads were ported into the water jackets,then re welded and re machined to seal up the water jackets,maybe just maybe one of them has a slight pin hole or crack,but i highly doubt it cause i dont smell anything in the ex no smoke or anything.and its also not pressurizing the cooling system. any ideas guys?

 

water leaking from the weap hole in the water pump.. pump is shot replace it

 

it dosent leak anymore it leaked for about the first 15 mins the car ran, and then stoped completely,or u think the pump is still bad?

 

id replace it to be on the safe side.. could of been some dirt/rust or something get in the passages and clog it up. then again pumps are designed to leak from the weap hole when they are going bad

 

Dave, foam in the coolant can result from either trapped air in the system, leaky suction side of the water pump, low to no coolant in the recovery system as well as a lack of the coolant recovery system entirely, or the water pump itself. Could also be from cheapie antifreeze w/lack of anti-foaming agents in the coolant....

 

ive only got water in it tracks are getting picky about cars with antifreeze in them,since i cannot find a leak anywere even pumping the cooling system upto 25psi and letting it sit for 3 hours. im gonna try putting a restrictor in the thermostat housing first to slow the water flow down since im not running a tstat.if that dont fix it then ill toss a new water pump in and see what happens.

 

My Fiero does that, old rx7, 83 camaro V8 and none of them had thermostats. I guess thats what you get when you don't run a thermostat but I never had any real problems and I dont run antifreeze because FL doesn't need it and water is more heat efficient.

 

I've heard running straight water will cause corrosion inside the cooling system, resulting in the nasty smell from the cooling system and rust coloration. Any truth to this?

 

The foam that you are seeing is probably the water boiling since the cap is off. The rows in the radiator break up the big bubbles, so you get a lot of small bubbles that look like foam. I've seen it on all kinds of cars where people have filleed their cooling system with straight water because a leak is too expensive to fix and pouring in water is cheap...lol

I know that you have a different reason for running straight water, but that's more than likely what it is.

forkvoid: Yes, running straight water does rust the inside of the engine/cooling system faster. Antifreeze/Coolant has a corrosion inhibitor and a lubricant to keep the water pump lubed. Straight water has been known to be a cause of a seized pump. Seen it on many cars.

 

I think the specific heat of anti-freeze is also much higher than water.
water=4ish
antifreeze=6ish

 

i dont see how it could be boiling when both cts sensors read nowhere near boiling temps reg street driving i might see 165* id have to dbl check my logs but i think the highest temp hit was 177*

 

Ever boil water for a pot of pasta? Notice how it isn't actaully at 212* but there are bubbles wising from the bottom of the pot? Water will start to release into a gas at about 170*. Just thought that it could be something you can think about.

 

hmm good point

 

water is 4.186x10^3 J/KgC* :P

 

Chemist/Physicist? heh