Obviously new, been digging thru previous posts and still find myself in not quite the same findings for a somewhat common problem.... Settle in folks this will be long and I might give a test.

Bear with me. I have pics to make sure I'm conveyin' what I'm getting at.

Alright I'll give you all the history I've got and you tell me what direction ya lean on the situation...

New to me 97 accord lx. Coolant looked good. Oil good. (neither show signs of being contaminated) Did seem to put out a quite a bit of water thru the exhaust initially, but it's quit that since being driven vs sitting.

Car idled in the drive for days (waiting on title work) no issues, noticed a slight puddle near the pass side of rad/overflow area. Start running car. all is well temp is fluctuating a bit but nothing major, and not hot. 200 miles no issue. opened the system that evening, topped off with water, (wasn't very low at all) ran it the next day 80+ miles and it overheated. puked out all the coolant. Limp it thru and get it home and determine it's pushing steam into the overflow (somewhat common issue) Basic troubleshooting ensues. (I should note at this point, we're not idiots with tools here, we've done some time turning wrenches.)

Chase it chase it chase it. found that we hadn't bothered to open the heater core on the refill from the initial overheat, find the fan on the drivers side inop. Replace. Both fans seem to function. (here comes some fun) I've jumped the green plug on the front side of engine, (circled in red in 1 pic) with the key and nothing happens. Twice when it was jumped and the key was turned off, it started the fan on the pass side. Have not been able to duplicate it kicking on fan again, but it consistently does not start either fan.

Jump the green plug on the back of the motor, with the key on and the driver side fan runs. regardless of these oddities, the fans seem to run as they should. one or both runs when the ac is turned on, and thru idling and motor revving it will run either both, or the other (non a/c one) by itself.

and yet the boiling overflow persists. (so far only after being driven longer periods, short trips, no bubblin')

So fearing the worst I rent a block tester. Negative for combustion gasses in the coolant. (and I've got a damn 8buck bottle of blue fluid I'll prolly never use again) Plugs are clean, but don't exactly look steam cleaned. I've got a pic of them too I can dig out if needed.

I've bled the system from the bleeder circled in blue iirc. the other red circled plug is the above referenced plug on the back of the motor.

Tried to pressure test the system with little brothers tester from his shop and couldn't get a good enough seal at the top of the radiator. (pic 3) I have to wonder if this is my issue and if I should mess with it or start looking for another radiator I don't need to afford. Also noticed the elbow going thru the overflow cap shooting steam so I gobbed it up with some RTV and still it just pushes the steam thru the cap. (but not the pinhole) I do have a new radiator cap on it.
Thinking of renting a different pressure tester from the parts store and see if I have different results with it.

I'd rather not do a headgasket or replace the head if it ain't needed. and I'm drawing a blank. I can't see any obvious signs of a leak anywhere, outside of what comes thru the overflow lid.

been running straight water til I get some antifreeze to put back in it, it's already puked out what I had left. Have not done the thermostat as it seems to be functioning, I have ran a infrared thermometer all over the damn thing even while it's steaming the overflow and the highest reading is just over 200 at the head, upper and lower hoses are within 10* of eachother in the 180-195 range. Seems to run about that regardless of steaming or not.

I swapped the pw and cooling fan relays back and forth with no change. (PW's work fine)


I fear I've made this far too long, I think I've included everything.

I'm looking for suggestions, ideas, whatever can help me determine what I need to consider next, be it headgasket or otherwise.

thanks.

 

:crickets:

lol

 

I'm going to focus on that dent in the sealing lip of the radiator neck. I think you'll need a new radiator.

But first, the fans and fan-switches. For 1997 the fan-control scheme works like this...

- Fan switch at the thermostat (red circle in your 2nd photo) has the authority to run the fans while the engine is on. If you jumper that wire, key on, BOTH fans are supposed to run. If not, then troubleshoot the fan relays & power circuits.

- The fan switch at the UPPER radiator hose only has authority for the first 20 minutes or so after switching off the engine. And it switches only one fan. So if you jumper that switch, you want to switch the key ON, then switch OFF to get one of the fans to run.

- This behavior is controlled by the fan-timer module (I think buried somewhere in the passenger-side dashboard). If the behavior is somehow farbed up, look at the fan-timer module.

Now for the radiator neck. After filling up the radiator, bleeding air out of heater core, etc, warm up the engine. Squeeze the radiator hoses. I have a suspicion they aren't very hard, becuase the cap isn't holding pressure. That inner lip (where you have the red circle) is where the pressure-seal isn't happening. Overflow goes to the plastic bottle, maybe spills out or steams off. But a good thermostat maybe keeps the temperature down so it doesn't furiously boil over. Antifreeze is gone, you're using water, so the green scum might not form around the plastic overflow bottle.

Now during cool-down, the vapor-space in the radiator condenses, and sucks water back in from the overflow bottle. That vacuum is maintained because your outermost lip of the radiator neck looks OK.

 

Thanks for the input Jim.

I pulled the thermostat and tested it, boiled it to open, let it cool to close, idled it around the 180 mark, my dog was quite upset over this as she couldn't understand what I was doing with her puppy crack (lazer pointed thermometer)

I'm hoping your right and it's just that lip, I've considered trying to gob it up or something to get it to seal, (we're broke jokes here) but think I might have to see if I can round one up. Which should be fun as this particular car seems to have different fans than the majority (3 mounting points vs 4, curved blades vs flat) so I imagine I'm gonna struggle to find the correct radiator.

Ugh.

better than a headgasket, but still can't rule that damn thing out either.

Oh and thanks for the heads up on the fans. I will be testing that out too. I guess that would explain why it was kicking the fan after the old lady was shutting off the ignition. But now I gotta figure out why the fan switch is only firing one fan (the new one)

thanks again and I'm still open to other ideas/suggestions/troubleshooting.

 

The fan switch in the upper hose has a higher temperature-setpoint, for after shutoff. I wonder if the 2 fan switches are physicall interchangeable, so the main one (@ T-stat) has too-high setpoint while the after-run switch has too low??

But that won't explain why only one fan runs when you jumper the main one at the T-stat.

 

Agreed. Nothing that lands here is simple. lol for me it's always 8 different ways of jakked up.

rented pressure tester and could build some pressure but the system won't hold it (think on account of the filler neck being gnarly) so I guess I'm going to swap out the radiator. Just got it pulled and gonna run thru o'really's? real fast and see if they got anything that will match up... dealer and my pop's both quote 145+. (pop's is a gm parts manager) vatozone and o'really's? claim to have one for 95 new... but I'm betting it won't be the right one.... taking the old one in with me.

gotta go fetch the kiddos and then I'll be back at it and hopefully have an update.

I swear if I buy this thing a new fan and rad, and still have to pull the head, it's getting some 00buckshot somewhere...

 

I think (hope?) that if your headgasket were bad, you would've seen evidence of combustion gas in the coolant (with your magic $8 bottle of fluid). Or some evidence of oil & coolant mixing.

If the radiator fans don't seem correct (like you said) maybe the radiator isn't original anyway. So if you can get something to fit and mount the fans somehow...?

 

got O'really's? radiator, had to change the trans line fittings to get it to go, but alas, it's in.

I noticed water coming out at the hose going to the overflow, right at the neck of the radiator, I put a clamp on it to see if that has any effect.

filled it up and bled it off and ran it to temp. this time both fans initially kicked when a/c was turned on. then it just ran 1, same one seemed to kick for cooling (driver side aka the new one) and the other hasn't tripped except for the initial starting and kicking on the ac to make sure it was still starting a fan after the swap.

Hoses are far more firm. still has air bubbles thru overflow, but far fewer.

gonna go run it a bit and see what happens.

 

I've never been able to bleed absolutely all air out. Always get a little bit at the radiator that works over to the reservoir during the first few hot-cool cycles. Squeeze the radiator hoses when it's cool, you can feel/hear sloshing if there's still air in there.

When the engine is running, and the fans switch on (whether AC or over-temperature) I don't think there's any control scheme to run the fans separately. No function for one fan to turn off differently than the other.

 

yeah I'm scratching my head on the fans. All I can say at this point is they both seem to work.

after running it a bit last night it kicked both fans, but it seems to lean more on that new fan, the older fan on the pass side has more of a shroud leading me to believe it's the hi temp fan, but things have been screwey enough on this car who knows.

ran the kids to school and back (~25mi) no issues. topped the system off before I left, it weren't real low but I topped it off anyhow. gonna round up some antifreeze to top off with tonight. been back and forth on running the heater and a/c (yeah we're in kansas) so I know water is circulating well. I'm going to have to change the temp control valve cause it's all rusted and won't let me turn full tilt either hot or cold, but it's not a blockage.

Thanks again Jim, I appreciate your input. :thumbsup: