99civ

So I was driving my stock 97 Civic daily to work today and at half throttle pulling out into the street my CEL came on. It ran fine and I made it to work no issue so I went outside a little bit ago, popped the hood and smelled coolant. So I searched, no leaks, no coolant on the ground, etc. HOWEVER, the "foam piece" facing the front of the car(its about the length of the radiator and maybe 1/4" thick) was soaked with coolant. I checked my coolant, looked a little low, but still some in the lines, etc. I pinned for the CEL and it flashed once, so 10, so IAT. My next question is, would the IAT cause any coolant issues? Keep in mind the CEL was on for a total of 5 mins before I got to work and did not overheat, idle rough, etc. Could it just be I have two small issues at once? Bad radiotor cap + bad IAT? If my resevoir isn't FULL how hard is it for coolant to splash up "through" the cap? Thanks guys. The hatch might become the new daily for a week, lol.

99civ

bump anyone

Former User

Replace the radiator and bleed the cooling system. Then check whether the IAT plug is wet with coolant. If so, dry it with compressed air and then reset the ECU.

99civ

So the IAT should be good then? It's just the coolant/radiator causing the issue? I'm a big dummy in two things, cooling system and electrical. Between my two hondas, this seems to be the only issues I run into, lol.
I also went outside and looked around and my transmission is leaking oil out of the dipstick hole and the dipstick was loose so I turned it clockwise and it popped back in.. I sprayed brake cleaner to clean off the mess to make sure it isn't leaking anymore.

apexi_rsx

id swap the radiator then bleed and reset the ecu as said before i IACV is on the intake manifold no where near the bumper where ur seeing lost coolant.

99civ

It's on the back of the intake box and one some 96-00(EX/SI) it's on the intake arm itself. But I am going to autozone tomorrow or Sat and will pick up a radiator and swap it out. Can anyone point into proper bleeding after flush? I read to "pinch" the upper hose as it bubbles but that is quite, not descripitve at all, lol.

apexi_rsx

just jack up the front of the car fill it with coolant and leave the radiator cap off. then start the car let it run and listen for the fan to kick on and off 2 times so you know the motor is warm and the thermostat is open. keep filling until its full most of the bubbles will go to the top so if the radiator is elevated all the bubbles will come out the radiator neck u don't need to pinch or squeeze any hoses.

99civ

Thanks, appreciate it.

Jrox.chase

you said that it blinked once, was it long blink or quick blink? I only ask because if it blinked one quick then its a 1 and that would be your primary o2 sensor. that is closer to your radiator then the IAT is, you might check to see if your o2 senor plug is wet.

99civ

I'll check again tomorrow but I did it like 3 times and it was def a longer blink... When my primary went out the last time(so the o2 is farely new), the car barely would drive and the car runs fine now even with the CEL. The weather here in ohio has been back in forth between 80sh all the way down to 46(on the way to work today) and I read that the IAT controls the car's temp through outside temp? I talked to a head tech at lexus(used to be tech at honda and was certified) and he said he would change the IAT and radiator cap first since they are the "cheaper" and "easier" fixes...22 bucks+12 bucks is way cheaper than a radiator. We'll see, I have most of the day tomorrow to mess around... I'm always going to replace a cam seal on the hatch because I have light leak and I know the cam seal is leaking so I hope its just that and not the(head gasket)!!!

apexi_rsx

usually its the cap only if its not sucking coolant from your overflow reservoir into the radiator when its low on coolant.

99civ

Well its low on coolant and its pulling from the reservoir tank... You ever get lackadaisical with a daily driver? Well I did and I'm in a way paying for it. I change the oil when need be but honestly I haven't looked even once at the coolant or tranny in god knows how long... Hopefully it's just those two issues, I'll know more tomorrow. I hate working on dailys because there's no "Yippee" at the end because its still just your daily, lol.

99civ

I'm also going to add coolant to see if it is leaking from the top of the radiator/and/or the cap... From what I've read more than likely its the top of the radiator but better waste a few bucks before 100.

99civ

Can you re-word that? I re-read it today and am trying to understand.. SO if it is NOT taking coolant from the reservoir, then it usually is the cap? So if I'm low on coolant and pulling from the reservoir, it's probably a radiator as been stated(which I think is correct). Here's two pictures...
1.)The wet spot is from my pouring coolant in.
2.)You can see the line of dry coolant(haven't drove the car in 2 days now) along the top of the radiator.
3.)That foam piece in front is still soaked full of coolant.
4.)The cap looks fine and normal and there's not a whole lot of coolant on it besides what there normally is.

apexi_rsx

correct.... if its draining ur overflow reservoir into the radiator when it gets hot and the reservoir is empty after u filled it. as others stated its most likely the radiator

99civ

Yeah that's what I thought you were saying. Sometimes when NOT is thrown in before a do I get confused, lol. Thanks again for the help from all of you. I'm going to order a radiator today from radiatorbarn and hopefully have it here for Tues since I hear they fast ship like some crazy asses.

99civ

lol hooked up a diagnostic and it came back primary o2. So the coolant got on the o2 sensor. SO looks like I'll be swapping radiators and air drying a o2 sensor this week. Thanks again guys.

92lxsleeper

you dont need to air dry a 02 sensor, the exhaust gets plenty hot to do it istelf. besides the only way for coolant to hit the o2 sensor is to have a bad headgasket and let coolant into the exhaust system lol

99civ

well i know for sure the car does not have a bad head gasket and I know for sure the o2 sensor was changed(by me) when it went bad last year... So in the same day my radiator sprays coolant and does NOT overheat, the o2 goes bad?

99civ

plus when the primary went bad the last time the car went ape ****... barely moved. The car drives, completely normal.

99civ

Still throwing a CEL for o2 sensor but replaced the radiator, some hoses, etc and everything is working fine. My moms ex, a lead tech at Lexus now, was a tech at Honda years ago said if coolant splashed onto the heatshield/o2 sensor area, it wouldn't take MUCH coolant AT ALL to "ruin" the o2 sensor. So even though the o2 sensor isn't completely out, it's not operating "properly" so I'll have to ebay up for one but thanks again to everyone who commented. Again, my hands are the the only hands that touch my car but sometimes I couldn't do it all without some expertise/feedback. Thanks again.

motegicivic

I hate to say it but the o2 is threaded in the manifold and coolant would have to get past the threads to affect it. I was attempting to get mine out and use a ton of PB Blaster and it did not effect it, still in there, no CEL.

Former User

No stinking O2 sensor has a snow ball's chance in hell to defeat my invincible big *** breaker bar.

motegicivic

Ron guess what I bought today.......

Man I am afraid I am taking the manifold with the O2 sensor lol.

I lost you on Invisible?

99civ

LOL I agree with all that I doubt the coolant "got to the sensor itself" but who knows what happened to maybe the harness, etc if coolant splashed everywhere? Also, maybe it was a spiff that both went wrong at the same time? Either/or my car is running normal so there is no head gasket issue, ie, "allowing" coolant into the exhaust valves because after switching out the radiator today, it smoked for maybe 30 seconds and hasn't been turned on in over a week and its "cold" in ohio today so nothing wrong with a little smoke.

PS: The best breaker bar is a big *** pipe...!