sgull

Have noticed a definite losing of coolant lately on my '92 Accord. I'll top the radiator off and make sure there's a proper level in the expansion tank, but then after driving around and checking it again I'll see the level has dropped, sometimes quite significantly. Had it topped off the other day and drove around for approx an hour at approx 30-40 mph. Afterward I checked it and it had gone down and took a full two quarts of coolant to get it back up to full again. I've looked carefully for any obvious leaks while it's running, idling in the driveway. Put dry cardboard on the ground under the engine and watched while it idled a half an hour or more, no dripping anywhere. Checked looking under heater core area, no sign of wetness/leaks there either. No hoses leaking or seeping, nothing dripping. I'm not getting any overheating (yet) but that's because I'm not haven't been letting the level get down to that point. But what I notice is some steaming coming up from below the radiator fan shroud area, although like I mentioned never actually seeing any fluid dripping down to the ground. Here's a video I took, for what it's worth: http://s207.photobucket.com/albums/b...ps1a341798.mp4
I'm figuring maybe the radiator is leaking somewhere in the upper middle area of its fins/tubes, and the coolant is just evaporating on the warm/hot radiator fins below the leak as it trickles down so that's why I never see it dripping? I was a little careless the other day when I was topping it off and ovefilled the radiator filler neck a little and so a little coolant slopped over and trickled down below the neck on the fins there some, and that caused some some steaming below. So I watched a while but it just kept steaming down there where I mentioned and video shows. And I drove around again today and to try to make sure if there was any residual still in the fins from my little spill it would surely dry up. So I got home and saw that the level of the radiator was down again (after being topped off), as was the expansion tank level down a good few inches. I can shine a flashlight through the front grill and can see wetness down on the fins area just below the radiator cap and downward from there. I can see the top seam of the radiator where the plastic meets the aluminum and its not leaking from that. When the car is idling and has been running a while, I get slight constant steam wafting up from the area down below the fan shroud, as per video but maybe not as visible or strong as what that shows, but still the steam as mentioned. It's been raining out lately and I don't have a garage so there's always some drips to some extent when I just open the hood and it drips down off the front off the front of the hood a little. Anyway, does my theory about the radiator maybe leaking and the leak evaporating on the fins causing the steam seem plausible, from my long-winded explanation here? any comments appreciated

jdowen2

Pinhole leak. You could dry some radiator stop leak but you should replace radiator, cap, hoses, and thermostat.

sgull

I'm not much of a fan of using stop leak, and anyway two quarts in an hour of driving around seems like maybe too big of a hole for stop leak. Will probably just replace the radiator if I'm certain that's what's leaking. Why is it a good idea to go ahead and replace the thermostat too, just because it probably needs one, they should be changed out periodically? Thanks.

EfyourK

Random but how well does the heat work? Check heater hose that runs from block to the heater valve next to the firewall... should be right Underneath/Next to the fuel filter.

sgull

Well the heater seems to crank out heat fine. I did glance (looked pretty good, though) down at where the heater hose(s) connect there at the firewall, and didn't see any obvious wetness or sign of leakage there. You think it seems my description of my rather mysterious coolant disappearance I might be missing/overlooking some possible leakage there? Wouldn't hurt for me to take a closer look in that area again. Thanks

hwyix

iTrader: (1)

I would never use stop leak unless it was an emergency.

Get it pressure tested. If it passes the pressure test when the engine is cold redo the test when it is hot. I have seen plastic car bits hold pressure fine cold but leak when they get hot.

sgull

Yeah I think getting it pressure tested is a good suggestion. Hopefully that will help me identify with more certainty the location of the leaking. From what I've observed so far it seems like a radiator core leak but I just can't be sure about it. I've never used one of those pressure testers before, but I noticed the local auto parts store has a loan-out program and has a cooling system pressure kit available for loan which includes step-by-step usage instructions. So I think that would be worth a try.

andys hondas

Check the heater hose under the distributor, usually the o-ring there leaks, then the hose swells up, gets weak, then leaks, pinhole right where it is swelled up. A pump-up pressure tester will usually show you whats up, unless its a headgasket

faran

Your leak seems pretty large, I was having the same issue as you.

Please try couple of things:

1-Do a pressure Test, you can get pressure tester from Autozone/Pep Boy's/Advance etc...
2-Radiator Cap is good?
3-By pass hoses, heater core and other hoses are good too?

Because, in my case one time radiator was bad, but while driving coolant was evaporating, also had a leaking hose, which was ONLY visible while driving so I was banging my head and finally figured it out.

Good Luck

sgull

1. Will get a pressure tester and do a pressure test if I can.
2. Radiator cap is new, from NAPA a month or so ago. So should be good, I suppose.
3. Hoses visually look okay, nothing obviously wrong with hoses jumping out at me. No leaking hoses from what I can see anyway. Heater core is tucked up in a tight box under the middle of the dash; looking closely as I can (without dismantling stuff) under there I see no sign of wetness anywhere in that area.

It seems to me that coolant is evaporating when the car is running, as I've noticed the steam wafting up from the lower part of the radiator when parked and idling as I've described. Seems like there is a more noticeable significant loss of coolant (level goes down) after I drive around a while.
So, in regard to the leaking hose you mention that was only visible while driving, I'm curious how was it visible when you were driving?

faran

Do you have a OEM radiator or aftermarket?

How about the hose coming from the block to the heater core? It's under the distributor on my 94 EX, not sure on yours though?

It was only visible because as soon as I put the car in 'D' and drive at a slow speed of under 20mph, I was able to see a puddle of coolant under the car, that's how I traced it.

Best thing to do is a pressure test, it's easy and you can do it for Free, if you loan it from any auto part store.

Out of curiosity, car overheats, how's the heat?

sgull

Radiator is an aftermarket replacement for the original factory one, replaced maybe 7-8 years ago or so, maybe 9 or 10 years, not sure but it's been a good while.
The hose from the block to the heater core I think goes right from the block to the heater valve by the firewall, but will have to double-check on my vehicle as compared with your location mentioned under the distributor. Why, is that an overlooked or often hidden source of such leakage or coolant loss as I'm experiencing? I'm not having a issue at all with the engine overheating, and the heater puts out good heat, if that's what I understand you to be asking.

sgull

Did a pressure test with a loaner kit from the local auto parts store. Leaks became apparent upon pumping up to operating pressure. Leakage most significant from a heater bypass hose connection, as well as from the other one too but not as bad. And some drippage from the upper radiator hose on both connection ends. I noticed after simply tightening the clamps, all leakage stopped completely. Previously, my checking with just idling in the driveway, these leaks weren't happening, or at least not obvious at all; apparently the operating pressure wasn't up high enough just doing that. So I'm about positive now that the steaming I was seeing coming up from the bottom of the radiator was simply from the upper radiator hose slightly loose clamp connection, enough to seep down onto the radiator and collect toward the bottom of it where it would start evaporating off. Could never spot these leaks happening without that pressure tester. After tightening up those clamps, pressure held fine on the gauge, with no more leaking happening. I had looked at the hoses before but didn't even think of checking the clamps for tightness. I suppose that should've been a basic thing to do at first? I guess those clamps can loosen up by themselves over time? They are all the worm-drive style clamps.

Accord1320

If you haven't already done so, replace ALL hose clamps involved with your heating (radiator hoses, heater core hoses, etc.) because eventually they WILL fail over time. I've had a heating problem not too long ago, and upon inspecting hoses and connections, my friend suggested replacing my hose clamps with the ones you can loosen with a screwdriver.

sgull

As I mentioned, these are all already the worm drive style clamps already (type you can loosen/tighten with a screwdriver). The OEM clamps on the hoses were those you know japanese style wire spring type clamps, which are usually always replaced with worm-drive when removed. So, my question is whether it's very typical that these worm drive style clamps can loosen over time; because mine apparently did.

jdowen2

I think the constant heating and cooling cycles could loosen the clamps. You should periodically tighten them.

dnguyen2010

Your car has a BIG leak. If you can't find the leak, then find someone who can.

Honda is very picky with aftermarket radiator, cap, and thermostat. Always go with OEM or radiator made by Denso.

sgull

As I reported (post #13 this thread), I was able to find the leak(s) by using a cooling stem pressure tester as suggested by others who replied. So there is no more leak. Using the pressure tester I found the problem, and after tightening a few loose hose clamps the leak issue ended, as I reported here a week ago.

eagle458

Just a thought . . . possible a blown head gasket? Is there white smoke coming from the exhaust, or brownish foam inside your oil cap?

sgull

No. As I've posted here already, I was able to find the cause of the leak and fix the problem. Please see my post #18 this thread. thanks anyway though for the reply