Coolant loss still not solved

[2004ep3hatch]

Hey Guys

Well my car has went through a lot of changes, I'm still however losing coolant somewhere. I did the block test so no gases are entering in and I have no coolant in my oil. Oil is still black colored when I drain it. I do not notice any leaking anywhere either.

I parked the car last night and topped the rad to the neck. I come out next morning and it just under the neck? With the car being cold and not running where is the coolant going? Is it possible the whole system is still not filled 100%? I already had bad rad caps on top of it.

I usually do not drive my car in the winter at all. Dose not driving the car affect anything coolant?

The other thing which might be related is that there is black sludge or something to that affect coming out of nowhere. Where and what can that be? This radiator is 9 years old as well.

Coolant was replaced last year and only driven maybe 1000 miles since then. I know when I'm low because when the car starts to get to 199 and the kicks on it never turns off because the coolant is low enough that it is not circulating.

image.jpg
This is before filled to the top

image.jpg
This is after

I'm going to get a new rad cap from the auto store again and see what happens while its running.

Any help from coolant experts please chime in.

[tinman5]

Doesn't appear to be a substantial amount. If the cap is old the coolant might/could be migrating into the reservoir. Easiest way to check that is a bit of hose and an empty soda bottle.
If you dont drive the car simply disconnect the stock reservoir from the radiator neck and run a hose to your soda bottle. I ran the hose straight down with the bottle on the ground. I used a drill to make a hole on the cap, nothing fancy. If the factory reservoir is vented do so to the bottle. If the hose runs all the way into the reservoir, do so with the bottle.
The only other outlet in the cooling system is the weep hole for the water pump. Hope this helps you diagnose this issue.

[2004ep3hatch]

Doesn't appear to be a substantial amount. If the cap is old the coolant might/could be migrating into the reservoir. Easiest way to check that is a bit of hose and an empty soda bottle.
If you dont drive the car simply disconnect the stock reservoir from the radiator neck and run a hose to your soda bottle. I ran the hose straight down with the bottle on the ground. I used a drill to make a hole on the cap, nothing fancy. If the factory reservoir is vented do so to the bottle. If the hose runs all the way into the reservoir, do so with the bottle.
The only other outlet in the cooling system is the weep hole for the water pump. Hope this helps you diagnose this issue.

I guess I'm a little confused, I'm letting the car sit without the rad cap. It's not going into the reservoir while its not running, I'm pretty sure of it. If you look into the neck where the hose is connected to the reserve bottle there is no coolant there. There is a little hole on the outside of the neck of the rad, so when the Coolant dose go over it enters the bottle as far as i understand. I'm pretty sure it's dropping in the rad itself, not routing into the bottle.

Also, the reserve bottle just has a plastic cap on top, I don't think it's vented. Unless I'm not understanding what your saying.
I see no signs of leaking but where is the weep hole for the water pump then. There is no liquid on the ground or around the engine bay I can see.

But that first pic where it's topped off, is where it should be at all times?

I'm sorry if I'm not understanding some of it. It's been a pain dealing with it.

[2004ep3hatch]

Also, any idea on the black gunk?

[tinman5]

No worries.
I'm on my phone 90% of the time but it looks like a ring of grime at the lowest part of the radiator neck on the second picture. Wipe it out with a shop towel or cloth and investigate that. I have seen such oily film on cars with failing water pumps. I have never looked at a K series water pump but in my experience the weep hole is not just an indicator of failing water pump bearing seals, it also allows bearing lube and slur to escape rather than leak into the cooling system.
I could be waaaay off, so hopefully someone more knowledgeable will correct me. I would GUESS you have a potential water pump issue. With the car idling can you hear any unusual whirring or even a low grinding sound?
Dont know your mileage but after 10 years its time for pumps and alternators to show their age. Just a thought.

[tinman5]

In regards to the reservoir, I did not realize you left the cap off. However I will add that my coolant level randomly fluctuates a few ounces as well. My coolant level naturally sits at the bottom end of the neck. I have filled it and checked it randomly and by and large the coolant for the most part will be at that same level. Once in a while the coolant will be all the way to the top. I accept it as normal as my temperature gauge is rock solid (for what thats worth) and I have no reason to suspect cooling issues.

[2004ep3hatch]

In regards to the reservoir, I did not realize you left the cap off. However I will add that my coolant level randomly fluctuates a few ounces as well. My coolant level naturally sits at the bottom end of the neck. I have filled it and checked it randomly and by and large the coolant for the most part will be at that same level. Once in a while the coolant will be all the way to the top. I accept it as normal as my temperature gauge is rock solid (for what thats worth) and I have no reason to suspect cooling issues.

I appreciate any help you can give. I just filled it all the way to the top. Both rad cap is off and res cap is of. So no pressure.

This is where it sits right now as of 8:42pm. It should not be dropping period correct? Lets see where it sits in a little while
image.jpg

So that black gunk could be from the water pump? There is no grinding or wheezing noises.

[2004ep3hatch]

Also, my temp gauge on the dash for some reason never moves when the car dose get hot. My kpro is reading 210 let's say and the gauge stays exactly where it is as if it was 190. Is this another indicator of something or a crappy gauge Honda gave us?

[2004ep3hatch]

No worries.
I'm on my phone 90% of the time but it looks like a ring of grime at the lowest part of the radiator neck on the second picture. Wipe it out with a shop towel or cloth and investigate that. I have seen such oily film on cars with failing water pumps. I have never looked at a K series water pump but in my experience the weep hole is not just an indicator of failing water pump bearing seals, it also allows bearing lube and slur to escape rather than leak into the cooling system.
I could be waaaay off, so hopefully someone more knowledgeable will correct me. I would GUESS you have a potential water pump issue. With the car idling can you hear any unusual whirring or even a low grinding sound?
Dont know your mileage but after 10 years its time for pumps and alternators to show their age. Just a thought.

I have 140,000 miles on the water pump, and radiator.

[tinman5]

I'm gonna guess Honda and Nissan have that in common. The temp guage on my 240 is little more than a three point switch. Cold, normal and screwed. Because of this I will be going with an aftermarket engine monitor as opposed to traditional aftermarket gauges or keeping a laptop hooked up to the Kpros. Like we dont have enough to worry about by owning Hondas.
Dont be surprised if the level does in fact shift. Remember the purpose of the water pump is to insure the coolant circulates. Once the car is off and the thermostat fully closes there is that period of cooling between the engine and radiator with the thermostat not allowing flow on one end, no circulation because the water pump is not spinning. The moment of expansion, vacuum and contraction caused by everything cooling at different rates.

[2004ep3hatch]

I'm gonna guess Honda and Nissan have that in common. The temp guage on my 240 is little more than a three point switch. Cold, normal and screwed. Because of this I will be going with an aftermarket engine monitor as opposed to traditional aftermarket gauges or keeping a laptop hooked up to the Kpros. Like we dont have enough to worry about by owning Hondas.
Dont be surprised if the level does in fact shift. Remember the purpose of the water pump is to insure the coolant circulates. Once the car is off and the thermostat fully closes there is that period of cooling between the engine and radiator with the thermostat not allowing flow on one end, no circulation because the water pump is not spinning. The moment of expansion, vacuum and contraction caused by everything cooling at different rates.

Yea, my car is completely cold so everything that has to happen expand/contract would have already. It has dropped a tiny bit already. So I'm going to wait till the morning to see what happens. I'll post up a picture.

Where is this weep hole tho! I can't see it at all.

[captaingamez]

first off, you should be using a HOAT coolant, like Honda Genuine Type 2, im not saying you have to use Honda coolant, but you NEED to use HOAT coolant (hybrid organic acid technology) on an aluminium block, Valvoline zerex is an example, the green stuff is not going to cut it.

how many miles do you have on your engine?, not your cooling parts, your actual engine, and have you ever done a head gasket. if you have never done a head gasket, i am putting my money there, doesnt mean it will get in your oil on a k series. I had a blown head gasket and it would seep into the cylinder when I turned the car off, slowly lowering my coolant level, it would not overheat, run weird, or eat coolant en mass, or even smoke when warmed up, so I never got coolant in my oil, and I never got moisture in my oil cap until it got really bad. I honestly dont think that a engine pressure test would have turned this up.

[tinman5]

Engines are funny like that sometimes
I also am running the blue coolant from Honda as well. Never really considered the implications of running the green stuff as I have only owned the EP for a few years. Good to know.

[tinman5]

As for the weep hole, I honestly dont know. I googled K20 water pump images and could not really see where the weep hole is. Unless it is right behind the pulley I saw nothing indicative.
I am now contemplating adding a water pump replacement to my cam/spring install.

[2004ep3hatch]

first off, you should be using a HOAT coolant, like Honda Genuine Type 2, im not saying you have to use Honda coolant, but you NEED to use HOAT coolant (hybrid organic acid technology) on an aluminium block, Valvoline zerex is an example, the green stuff is not going to cut it.

how many miles do you have on your engine?, not your cooling parts, your actual engine, and have you ever done a head gasket. if you have never done a head gasket, i am putting my money there, doesnt mean it will get in your oil on a k series. I had a blown head gasket and it would seep into the cylinder when I turned the car off, slowly lowering my coolant level, it would not overheat, run weird, or eat coolant en mass, or even smoke when warmed up, so I never got coolant in my oil, and I never got moisture in my oil cap until it got really bad. I honestly dont think that a engine pressure test would have turned this up.

I have about 40,000 some mileso on it, I did a head swap on it a few years ago with. Brand new gasket.

Only put maybe 5000 miles if that since then. I did the test to see if gasses are entering the coolant with the bulb.

How else do I check then? It seems to stop lowering to that point in the neck of the rad. If I had a blown gasket, would that not show up with the gas test I did?

My oil is not chocolate milk either, it's the right color to me at least. I am wondering about the gunk I keep finding tho.

I did not know about using certain coolants either. I guess I'll have to find the ones you posted. What will having the green do?