Sorry this is long winded... just don't want to leave out something important!

Over the years I have had my share of coolant leaks, but this one has me baffled. I searched, but this one is a hard one to search on so I got nothing helpful.

We have a 2003 Honda Civic 4cyl manual. It was in a front end collision before we bought it 1.5 years ago. To my knowledge it has a new Radiator. Well everything has been fine for 1.5 years.

Today we drove an hour to a doc appt. Parked. Car sat for an hour. We then left the parking lot. Were sitting in line to pay and leave. There was a downward incline. When we leveled off we smelt coolant. I thought it was the old truck in front of us, but he left and I still smelled it. I stopped in the center of the highway and looked under the car. We were dripping. Quick peek at the gauge… normal. So I pulled into a lot to check it out. I shut off the car and opened the hood. I expected to see something dripping or spraying. NADA. Coolant was slung around though. It was on the hood… front of motor… rad fan shroud… rad hoses (both)… lower support bar (below lower hose). So I pull out the only thing I had… Mcd napkins and start wiping down what was not piping hot…

I then looked around for new moisture from a leak. Nothing. So I turned on the car… nothing. Then I thought hmmm… fans… turned on AC. They worked. Had my wife rev the gas to see if something would sputter out. Nothing again. OK now what. Gauge was still normal. So we drove part way home and I stopped to check the car again. No new spray. Now I know from the past that if you have a BAD leak you might not even run hot, you will go straight to cold. But this did not happen. Car never ran hot, nor cold. Just smack in the norm. So that told me there was at least enough coolant in the system to give the gauge something to read.

So that being said the wife dropped me at work and took it the rest of the way home w/o incident.

My only thought is a possible leak in the reservoir? It seemed low, maybe even empty. I wonder if it might have enough pressure to spray out till it got below the crack, or maybe the reservoir hose itself? Of note… when we got the car I had to make him buy a reservoir cap because it had none. I noticed the screw top in the reservoir was a bit messed up. Maybe they kept the old one from the wreck??? If it might be the reservoir, are there any DIY instructions on swapping one out?

As most of my knowledge lies with the domestics, are there any other lines that contain coolant I should look at? I plan to crack the rad tonight and take a peek once the system cools, so I can see how low we are.

Would the best thing be to put the car on ramps to elevate nose… refill the rad, sqeeze hoses and see if they leak, let it run the bubbles out (if any), then fill the reservoir. Then see if it repeats the leak?

Thanks for any help you can lend me!

 

The best suggestion I have for you if you havent found it yet is to top off the coolant system and get it hot to build pressure and then let it sit and look for any new coolant drips or if you have access to a pressure tester that would be the best way to find a leak with out having to heat the coolant up but you would need to have a full system for it to be 100% accurate also if you do have access to a pressure tester let it sit for about a half hour and watch the gauge for any pressure drops

 

There is also a dye for coolant to track a leak.

 

Would look for a pin hole leak in the radiator or a hose. As stated above a pressure tester is the surest way to find a leak.

 

well I found the problem... There was a hole in the top of the reservior. I assumed it was the issue, so I bought a new one and as I was taking it out to replace the old one I also found a hole in the reservior line. I replaced both.

I then jacked the front of the car up. Opened the rad cap and filled it. Then ran the car till the thermostat opened. Then I filled it again. I let it run for quite some time to see if any additional leaks would present themselves. I even lowered the car and let it run some more. When I was satisified I topped off the reservior and all has been well since.

Based on the tear in the hose I would say it was the culprit. The hole in the top of the reservior has been there since we bought it and has never given me an issue. The car was wrecked in the front before we bought it so I'm sure there was some courner cutting. One of which was replaceing the reservior and line. The line just finally had enough of expnading and contracting and gave in to the split.

 

My '89 has a bleed valve for the coolant on top of the engine.
Might check and see if yours has something like that to be sure and get all the air out.

 

My 90 has the bleed valve also but I still ran it as Honda suggests & bring it to temp let the fan cycle two times then top off & you should be fine.