I decided to start the car up today and load it with tools as I was planning on driving it from my mom's house to my new house in 2 days. I had the car idling for about 10 minutes and I noticed my engine started to get very noisy (lots of metallic sounds). Well, when I went to the front of the car, water/coolant was squirting off the top of the water pump. Hopefully, I didn't damage/overheat the engine. When I checked my water temperature gauge, after I shut the car down, it read 160F.

I'm glad this didn't happen when I was driving. All of the hoses are about 2-3 years old. I think it may be this rubber plug on the water pump spout. It's cracked to hell. Anyone know of a good replacement? Hopefully not rubber. My understanding is this is where the heater hose would attach to if I still had my heater core.

Could it be something else? Shouldn't the radiator cap bypassed the pressure to the catch can? Well, I guess if the cap gave out, there would be no pressure.

I think the black cap on the pump heater hose nipple split way before the rad cap reached its psi limit so it did not let it puke into the overflow. Not sure what to recommend for another one but I used some white rubber chair leg protectors from a hardware store & no issue! (not recommended tho!) You can get a "tank valve" from O'reillys for less than $3 (1/8 NPT male threads) & screw it into the coolant temp sensor port in the top rear of the block & pump it up to 5lbs or so for a start & see what you see (I wouldn't go much over 10 if even that). You'll see an issue way before that. with the system full of coolant (not compressable) & very little dead air space it will reach that very quickly so put your air chuck on it for a split second at a time then check it with your tire gauge.

this is why it is not a good idea to block the by-pass hose. it causes cavitation/pressure at high rpms with thermostat closed.

the heater hose nipple is ok to plug off. just as you have.

you can get the new block off caps at local AP store. when asking = heater core block off caps. most times in the HELP section.

I fill the WP nipple with a good rtv and let cure 24 hrs, then cap it with one of the rubber caps. this way I can always go back to heater lines.

I had a cap blow at 4800 rpm in 2md gear. made a loud bang (cap/water hitting hood?) engine falls on its face and dies. thought I blew engine.

sucked water flooding it and sucking my open filter flat to the base killing it.

yea every couple yrs those need replaced for sure. why I started filling the port on my junk when not used.

I add a spring in lower rad hose to keep them from sucking flat at higher rpm.

check/watch those hose clamps cutting into the rubber as they get old and shrink.

good idea to change both = less than 10$ not counting coolant.

and that is a very nice clean looking engine sir! can of engine brite to wash it down on the list?

do you have the 6 vane or 8 vane pump on there?

6 vane for a/c and 8 vane for non a/c

are those under drive pulleys?

FYI. pump rpm

6 vane on a/c as it uses a smaller/faster pulley to pump x amount at idle.

8 vane on non a/c as it uses a bigger/slower pulley to pump same x amount at idle.

running 8 vane with a/c pulleys can cause pump to cavitate at high rpms for extended run times.

looks like you have a stock non a/c wp pulley size.

I like to run a 8 vane non a/c pulley with a HD max cooling thermo-clutch 7 blade fan on my hot rod.

Yeah lose that rubber cap, I had one of those on my 340 and it lasted 1 day. it looks real nice and clean but they suck. tap pipe threads into the nipple and put in a pipe plug. if you want heat just unscrew the plug and connect the hose. is it worth getting stuck or losing a Head for that?

This is what I've done in the past before going to an electric pump.

Do you happen to know what thread? The only pipe thread tap I have at work is 1/8-27 NPT.

have went thru 3 here in AZ,the rubber dries out and cracks....got a new one on there now from Germany....got it off ebay, those help ones are crap.

A closed end 1/2 lug nut for aluminum wheels fits perfect inside a short piece of heater hose...looks a little funny but doesn't fail...
I tapped the ones on the Duster...maybe 1/4" NPT? definitely check to see if you also need to drill it 1st with a bit for the correct thread...Don't force the tap as the aluminum is thin...Maybe a little grease to capture any shavings...
If I had to do over again I would have cut them off closer to the housing and then tapped them...More like the way the cast water pump fittings install in the bottom pic...

Someone had recommended a 3/8 NPT tap. I like the grease idea, I really don't want to take this pump off.

No need to make a big project out of this. Get a small length of the correct size heater hose. Slide it over the nipple coming out of the water pump. Put a small piece of aluminum bar stock of the correct diameter in the top of the heater hose piece and fasten each end with clamps. This way you'll never have to worry about it leaking again, and it will take all of 5 minutes to fix.

And if sometime in the future, you ever decide you want to hook up the hose to the heater core, you didn't destroy the threads in the pump.

Got a dial caliper?

The following chart shows the hole size needed for various tapes. Find the pipe tap that fits.

for it to be aesthetically pleasing I would as said cut the nipple off & NPT tap it for a plug (I'm assuming you ain't never gonna use the heater again with this engine/pump) like in the pic & first stuff a piece of rag in there to catch the shavings. If the (final) appearance ain't objectionable as said the piece of heater hose with a plug/2 clamps would be the easiest/fastest.

Not sure what you used.
Looks kinda like it was made for the purpose intended.
There is definitely cracking visible.
It kind of looks like the clamp may have been to tight.
I usually just use regular heater hose and a pipe plug.
Doesn't look as nice.
Never had them leak.

i had one of those rubber deals on my car, i haven't even been driving the thing really, and still it was dry rotted/cracked after a year or two.
the housing of the water pump was kinda corroded and leaky at that nipple area so i just replaced the pump.
bought a PRW pump and it was tapped so i could put a plug in the heater hose outlet. no more worries about that rubber cap...