Slowly losing coolant over time, SR20

[jspaeth]

My car is losing coolant, very slowly over time.....like if I fill it to the brim, then maybe 3-4 months later, it is down to the top of the metal part of the radiator (like maybe 2 soda cans worth of water). It's been doing this for probably 2 years or so.

I NEVER have any coolant in my oil, and NEVER see any coolant coming out of the tailpipe.

Also never see any leaking on the ground anywhere, and it's not in the overflow.

Just put a new metal HG on about 4 months ago, when I rebuilt the top end and had the head milled flat.

Never overheated the car really....one time had a VERY minor overheat in stop and go crawl traffic when my fan ground got loose and fan didn't come on....turned her right off and fixed that issue quick though.


Any thoughts on where it could be going? Worth worrying about

[D.Adams]

Maybe the the coolant monsters are drinking it those lil things can be a pain in the arss.

jk

check the water pump weep hole. then check the heater core that might be leaking. i hate to reccomend radiator stop leak but give that a try

[drift_king]

check if the heater hoses are dryed out, my buddy had a slow leak (not as slow as your though) and it was a rotted heater hose that ended up just blowing and all the water cam out.

[jspaeth]

Ok thanks guys.

When I had the head off when I was building it, I took a look at all of the coolant-related hoses, and they looked fine.

Like I said, I never see even the faintest signs of dripping under the car, and never any white smoke or water in my oil.

hmmm

[Rabboni]

Have you done a leakdown test. It probably isnt a blown head gasket, but it cant hurt to be sure.

[jspaeth]

I strongly doubt this.

The car performs fine, and then HG is a brand new APexi metal HG installed 3 months ago.

It did this BEFORE the HG install as well and before the head was decked/milled.

If it's a HG leak, then it would show up during a COMPRESSION TEST (no need to do a full-out leakdown test), but my compression is essentially fine: 145-145-145-155 with a shitty tester.

[D.Adams]

i would go through all the heater hoses.. is there ever a sweet smell with the heater on.

[93nismo]

look at the carpet under the heater core under the dash. you might see a little stain if it dripped there.

[jspaeth]

Originally Posted by 93nismo

look at the carpet under the heater core under the dash. you might see a little stain if it dripped there.

Will do....it should be easy to smell if it's dripping into the car, but I don't really ever smell it.

[D.Adams]

Originally Posted by jspaeth

Will do....it should be easy to smell if it's dripping into the car, but I don't really ever smell it.

i didnt smell mine i just found a big wet pot. if it s a slow leak it might be drying up before you notice it .

[93nismo]

Originally Posted by jspaeth

Will do....it should be easy to smell if it's dripping into the car, but I don't really ever smell it.

you might not smell it if its a really tiny amount. and if your a smoker or youve got an airfreshener id imagine it would mask the smell a little as well

[lightsource]

If your head is okay and you're 100% sure your coolant lines for your turbo are all connected (line coming from block and line coming from rear of engine) and not leaking...

That means...

1. Bad Water Pump
2. Heater Core Leaking
3. Hoses Leaking (either constant or return... check both!)
4. Water Outlet @ Top of Block (feeding to radiator)
5. Leaking Radiator
6. Coolant Reservoir Tank should be connected
7. Coolant Reservoir Tank might have a crack in it

[jspaeth]

Originally Posted by lightsource

If your head is okay and you're 100% sure your coolant lines for your turbo are all connected (line coming from block and line coming from rear of engine) and not leaking...

That means...

1. Bad Water Pump....Don't see how this would be the problem, but my temps are fine and water pump seems fine.
2. Heater Core Leaking...Possible
3. Hoses Leaking (either constant or return... check both!)....Pretty sure IACV, throttle body, turbo lines, and radiator lines are all fine.
4. Water Outlet @ Top of Block (feeding to radiator)...I'm pretty sure this is fine.
5. Leaking Radiator....Didn't check this, but it's possible I guess.
6. Coolant Reservoir Tank should be connected....Is connected.
7. Coolant Reservoir Tank might have a crack in it

....Good point, will check this.

[midnight_rex]

sounds like the coolant is evaporating somewhere.

[93nismo]

your rad cap might not be sealing the way it should. just an idea. might have the slightest leak when under pressure. but i would think you would see residue from it around there. water pump is a good idea. but i think if you overflow tank had a crack it would be leaking a little faster. dosent hurt to check though

[fliprayzin240sx]

Buddy of mine with an S13 redtop have the same issue. His shit was leaking on the turbo water line at the back. Basically, when the car is hot and the cooling system is pressurized, thats the only time it would slowly leak. Since the car only gets that hot when he's driving, he never see any coolant leaking. He just notice that his radiator is low ever couple of weeks.

I'm not saying its leaking from the same area but you get the idea of what could be happening.

Also, is your reservoir overfilled? Sometimes if you have a shitty rad cap, itll let coolant out into the reservoir but not let it back in when its cold.

[Propaganda]

Easy.. go to autozone and rent their cooling system pressure tester and buy the adapter from advanced auto parts ($20) and perform the test.

[jspaeth]

Ray, I have the S14 waterneck, so the line to the back of the block is eliminated....actually, the rubber hose has a large bolt shoved in there with a hose clamp on it really tight.

But yes, like you said, it probably is a slow drip from somewhere only when it's hot.

If that's the case, then I have no real problem just refilling it whenever....it's more trouble to track shit down back there and fix it (with the whole bottom mount setup and all).

I just am hoping it's nothing to do with HG issues, which I don't think it is at this point.

[Ceepo]

I had this same problem one of my hoses under my intake manifold was leakin tiny amounts of coolant, have you check there?

[steve shadows]

If it's only happening every 3-4 months really wouldnt worry.

That could be caused by anything, even just it sloshing around in a hard turn from time to time or burning off through a micrscopic pin hole in the radiator kneck