Mike1984

Hi, I have a 1998 Honda Civic 1.6 Vti (111k miles).

Recently I have noticed the coolant level in the reservoir drops entirely except for about 2cm in the bottom and the radiator stays full when the car is OFF.

I have no gunk under the oil cap and absolutely no white smoke when the car is driving at all. I cannot find a visible leak and have checked that no air remains the system (though only by releasing the radiator cap).

I figured that because the radiator remains full and the coolant level drops even when the car is off (wasn't touched for 24 hours and the level dropped) that there must be a leak. I have placed cardboard under the car and not found a single drop from anywhere.

Also, I cannot smell antifreeze when I open the bonnet or when the car is in motion.

I am not very mechanically minded and am about to start pulling my hair out.

Any ideas are more than welcome.

Thank you for taking the time to read this.

Mike

Broskiballa

Okay, so just to get a full analysis of the issue. You start with a cold sitting senario. The resivoir is full to begin with? And then when turned on to normal opperating temperature, your resivoir is sucked almost completely empty except for 2cm of liquid remaining? Do you have to fill it every day? Do you smell coolant?

Whens the last time you replaced your water pump? Well.. I guess if you had a leak there you would see it, unless its a slow leak where the heat is just evaporating the coolant. I notice that when my cars off my resvoir is at the full line, and when hot, my resivoir goes to about the minium line. The thermastat doesn't open until it reaches the proper temperature, I almost want to say its normal unless you have to consistantly refill your resivoir.

Mike1984

Hi, sorry, I wasn't very clear with my original post.

The reservoir can be filled at 9am in the morning when the car is cold (the radiator is constantly full), then I don't touch the car for 24 hours, go back to it the next day and before I do anything, I check the fluid again and it's totally gone except for the 2cm. This happens when the car hasn't been used, at all. So no operational parts have moved, the key hasn't even been in the ignition for 24 hours.

I had a look this evening with an "apprentice" mechanic who looked for the gunk, smoke and smell. None of which were evident. I also took the pipe off the reservoir (leaving it attached to the radiator itself, I believe it was called "header" but don't know), put it in some clear water in a jar and ran the engine to check for bubbles. (Someone advised me to do this...) No bubbles came out.

I also checked again for smoke, had the car up to 60mph (fastest allowed around here) and was not "bumpy", "laggy", "slow" at all.

The fluid I put in at 11am today has not moved 1mm during all of this activity. Which is odd because it only took 5 hours for it to lose 50% last time.

Last thing to note. I have noticed a small amount of steam being released from the radiator cap after a hard, fast, drive. Not a huge amount mind. This has indicated to me to get a new cap, which I have ordered. BUT - would a loose cap on the radiator allow the reservoir to drain whilst the car just sits on the drive, untouched for 24hours?

Sorry I can't be more helpful.

Getting a "pressure" test done on Saturday. (I think that's what it was called, lol) And I have some "sealant" advised by a few garages that I haven't put in yet. Don't really want to if I'm honest. Either way will wait until pressure test is done.

Sorry I'm not very good with naming parts. I have ZERO clue about it and have researched all I can online.

Edit: No idea on the water pump. Can't find anything about it in the History.

Broskiballa

Steam is normal. It actually sounds like your car is normal my friend. I really think your over thinking it. If you're loosing an extreme amount that you consistantly are having to put in a bunch of coolant every other day, I'd see an issue. If it goes low, top it off. Mark how many miles you notice before it goes low again. Something tells me its simply just being utilized when your thermastat kicks in.

Mike1984

Thank you for your reply Bros, but I am still worried about the fact the reservoir totally empties itself when the car isn't doing anything. It must be going somewhere. I'm probably just a bit thick, but to me, it can't be normal that ...

Cold Car 9am Monday - Res Full, Radiator Full
Car not touched for 24 hours. (Not touched at all. Not one single bit.)
Cold Car before I drove it I checked and 9am Tuesday - Res bone dry and Radiator still full.

Former User

Get the pressure test done and don't add any sealants to the cooling system.

Mike1984

@ RonJ@HT,

Can I just ask why putting sealant in is a bad thing? As you can see from my post I don't really want to anyway. Just wondered what the specific reasoning was behind it?

Cheers,

Mike

grumblemarc

iTrader: (4)

Because it will more than likely clog the system and maybe even cause an over-heating issue. That and they just do not work.

Mike1984

Ahh right. I was sort of basing my "not wanting to" on not wanting to introduce a foreign agent to the mix. Guess that's the same in principal.

Anyway, my issue confuses me further still now. Been 36 hours and only lost about 3mm! (Which really doesn't concern me) lol. This is confusing the **** out of me. But, after the pressure test I should hopefully have a better idea of what's occurring.

Had a little more steam from the Rad Cap tonight. But only for about 2 seconds when I opened the bonnet. (Had just driven about 2miles at 60mph in -1oc Temp's)

Cheers for all your help again people.

pityocamptes

Overflow tank filled and car not used for hours and tank almost empty? If so, you may have a leak in the overflow tank. Perhaps the plastic tanks on the rad are leaking? I had a very small leak on the tanks and basically until it got worse I could not figure out where it was going. Couldn't really smell it either - just evaping out during normal driving. I know you can get the dye and light kits for cooling fluid leaks. They work pretty good. Might give it a try...

Mike1984

Hi Pity, took the Plastic Overflow tank out and inspected it for holes. Nothing showing. Capped it off and submerged it under water to look for air leaks and it held fast for an hour.

Are the plastic tanks on the rad cheap to replace? (Not that cheapness is a factor really, if it needs doing, it needs doing. lol)

Along with the pressure test on Saturday a "sniffer" test was mentioned. Apparently this uses dye so it might be the same thing you are referring to.

Won't update now until Saturday, but I'll post my findings.

Cheers again all.

Mike

pityocamptes

I think my tank from Autozone was like a hundred, somewhere in there. It was not too bad of a job, so you might want to try replacing it yourself. The place to look for leaks is where the aluminum finger clamps hold down the plastic tank caps. You could see heat stress "cracks" in the plastic on mine, and it was slightly leaking out where the tank and rad meet together.


Also, do you have an AT or MT tranny? If you have an automatic tranny the lines run into the radiator. Have you checked your fluid in the AT, if you have one?

Mike1984

Manual Transmission.

Now that you have said that about the radiator, it got me thinking so I went and had a look under the bonnet. (It's 11pm here so pretty dark and -2oc outside...brr).
Looked along the top of the radiator where the cap is, and along what I assume is the back of the radiator (closer to the engine than the fan side) it has a series of "notches" along the top. Clearly to hold it together I would assume. One of these notches looks to have a small "nick" on it.

I imagine this will show with the pressure test if it is the cause of the leak. Would this allow the fluid to escape whilst the car is stationary then?

(Also, I am rubbish with cars, so there is no way I could do this sort of work. lol.)

Cheers,

Mike

pityocamptes

Also, have you pulled each plug and looked at your plug, and take a flashlight and look down into the cylinder - a coolant leak will show a cylinder and plug all shiny and new. Leak could be small enough where you are really not seeing any white smoke, or coolant in the oil. Just a thought.

pityocamptes

Probably not, as when the engine cools down it pulls a vacuum until the system equalizes - reason for overflow tank running low and high during normal operation. You usually see the coolant coming out the tank/rad joint area when the system is pressurized, or right after engine shutdown when the engine heat soaks...

I assume you park this outside? Your leak, if external, might be slow enough to evap or absorb into the ground. I like using kitty litter as it gives you an idea of where the leak may be coming from. The clumping type works pretty good, you just have to make sure its not going to rain or snow as it will not work. Usually put down some kitty litter (clean) under your vehicle and then park it for the night. Check the litter for fluid clumping the next day, gives you an idea where the fluid is coming from. Perhaps run your engine in idle for a while with some litter underneath, shut it down, and look at it a few hours later (when engine completely cools)?

Mike1984

Yeah, the car is parked outside on the driveway. I have had some pure white cardboard underneath the entire engine block for three days and it's totally clean and dry.

Will try and look at the plugs if the pressure test finds something I cannot see.

I just really don't want this to be a headgasket issue. If it is, I may as well junk the damn thing. lol

Mike

Mike1984

Update. Okay, so since the last re-fill on Thursday morning, I have only lost 1mm of coolant (like that matters). Makes a nice change from a full tank every day. (You wait, I'll check it later and it will be empty.)

As I have no ideas about this kind of thing, I used the internet as a guide. All I have done is as follows....

Took out the reservoir and the pipe that connects to the header tank. Flushed them both through with water. Re-attached them.

Tightened up the Rad Cap and replaced the seal.

Tightened all the clips on the hoses.

Blew some "air" out of the radiator through the pipe from the header tank to the reservoir . (After disconnecting it from the reservoir first.)

The radiator is now using the reserve tank to dump coolant in when it gets hot (which is wasn't before). I know this because I checked the lvl and it was on MAX when I went out, and slightly above when I came back. So must have come from the radiator.

At the moment, this seems to have slowed (if not fixed) my issue. Here's hoping.

Oh and Pity, I checked everything you said mate, and did the cat litter test (was bone dry and no clumps). Also, the plugs looked normal. (Found a thread on here with pics of plugs and compared them.)

Cheers everyone for your assistance. I am still doing the pressure test this afternoon, just in case. Will post findings tomorrow.