Jack Murphy

Hello everyone, this is my second post here and I appreciate the help I've received from all of you so far.
(Car: 2000 Civic EX D16Y8 vtec)
(recent work: Timing belt and water pump done less than 500 miles ago, as well as valve adjustment and all new drive belts)

So for my problem, today I noticed a rather large puddle of coolant directly under my reservoir. So I popped the hood to take a look and it looks as if it's coming from the small hose leading to the overflow tank. (see pics) The spray reaches all the way almost to my passenger strut mount and is visible on my hood and ram intake filter D: (see pics) It is also on top of the plastic reservoir cap so I know it's not that seal (or exclusively at least) I was frantic about a possible head gasket failure as I had JUST put about $800 into my timing belt and water pump job, as well as drive belts and valve adjustments.

I immediately searched the symptoms and how to check for sure, and I looked at my oil but with the fresh oil change it's hard to say whether it's just the lightish color of the oil or whether there's coolant in it. I also took off the rad cap and started the engine and inspected the coolant inside the radiator. It did not spray out, nor did not see the bubbles I was supposed to see. This gives me hope. Also yes, I believe it is the original rad cap. (visible in pics attached)

The coolant level is still fairly high due to the shop refilling it about a week ago, but I've noticed before in the past that my overflow had been very low for some time with no overheating or performance problems? so this could have happened before and I just haven't noticed it. (Also, just for extra info, I do have an oil leak, which looks like it's coming from the oil pan seal, so I haven't worried about it too much (it's on the get-to-it-eventually list)

I also looked at the coolant in the resevoir to see if there was any oil present. I have black tar looking stuff on the inside of the res. (a quick search will tell you that's fairly normal) but no film of oil on the surface of the coolant. Another good sign.

I have never noticed an abnormal amount of white smoke coming from my exhaust, save a few cold mornings before the car is warmed up. Yet another sign against a failed head gasket being the cause.

I have heard that the seam between the metal radiator and plastic top part is a candidate for leaking. You can see in the pics, there is some coolant visible on the plastic, but only in puddles or droplets. However it is far less than other surfaces. Does this mean that it in fact could be the seam that failed but all the other coolant just burned off? (there was a small smoke plume when I turned off the car, could be that)

I plan to do a compression test tonight to rule out a head gasket one more time just to be sure. Wish me luck. Any and all help or suggestions are greatly appreciated, thank you very much Honda community!!

TomCat39

Are you sure it's coming from the small overflow/reservoir hose? Have you found a tear or hole in this hose to confirm?

In your last picture I see decent amount of moisture in the seem circled in red but do not see wet drops above drooling down to the seem.



This to me looks like the classic plastic tank crack to me and just requires a new radiator, and purging the system of air afterwords via the FSM procedure.

If you have a head gasket failure that is not putting coolant into the oil or oil into the coolant, then it's coolant going into the cylinders. You will know as it will misfire first start until you rev it a few times to burn the coolant off. As well, the coolant recovery usually tends to get overflowed to the top above the max line. And the main coolant hoses on the radiator tend to stay hard with pressure all the time. I know as I just traded my head gasket failure 95 civic hatch for my new Honda Si.

The way the recovery works is when the car is cold, the reservoir can be low but at or above the min line at the bottom of the tank, then when the car is hot it can be right at the max line near the top of the tank. The min to max is the operating range to account for the coolant expanding and contracting from temperature changes (hot vs cold).

The last head gasket possibility doesn't involve the coolant but would still cause all time misfiring and that is the one between adjacent cylinders.

When you do your compression test with all 4 plugs pulled out, shine a strong flashlight down into each spark plug tube and inspect the piston tops, if any of the plugs are debris free and the piston top is not black with carbon, it's sucking coolant. If all piston tops are black with carbon, your head gasket is quite likely a-okay and you just need to replace the radiator and do a fill and purge of the cooling system. Sucking coolant into the cylinder steam cleans all the carbon out of the cylinder and the piston top looks almost brand spanking new.

Jack Murphy

I did the compression test last night with a faulty tester from AutoZone. (The level would go to zero between ctanks instead of accumulating) so i dont think the readings i got are necessarily correct, but I'm farily confident my compression is not compromised beyond normal wear from almost a quarter million miles. The numbers i got from 4 to 1 was 135 120 135 120. A little bit consistant at least

I attatched a picture of my plugs. They look a little dirty on the threads, but the mechanic JUST put in new seals, so hopefully the seal leak dissapeared when it was worked on, and that's just residual

thanks for the input, I'll look into getting a new radiator, much cheaper than an engine rebuild!!

TomCat39

Plugs look normal with just a slight film of tan ash on the top as they should.

I believe your head gasket is fine.

Hamster65

I'd say there's a high chance you have a small crack in the top plastic part of the radiator. I had to replace mine a couple of years ago for the same reason. The crack was hidden under where the metal tabs are crimped over the plastic. The radiator is super easy to replace on these. I had the old one out and the new one in, in under an hour.

Jamo2390

Hey there , think I can shed some light on this situation. What I would do first this is wash off all coolant that has been in that air with some water then let it dry. If there is coolant missing from the radiator get some coolant dye from the parts store and put the whole bottle (couple oz) into the radiator then fill the rest with coolant. Run the car a while let it reach the point where it's warm enough, or cold wnough, to let the coolant start leaking. You Wil instantly know where that coolant leak is for the coolant dye will make the coolant a bright fluorescent green. To further see the brightness of the dye use a black light if you have one. A side note though, if the car is completely cold and you start the car and you have coolant spewing out of the place of the leak that indicates you have pressure coming from an alternate place other then the cooling system. That can only be cause by a head gasket. If you find the leak a cure it. Let the car warm up and cool down a few times then pull the spark plugs out and use that black light on the tip of the plugs. If you have a coolant leak in the cylinders you'll see the dye on the plugs! I hope this helps for I have diagnosed any cooling problem leak with dye and it has never failed me!

DeCoY

I don't understand why you would suspect a head gasket at all, a timing belt job should have zero effect on the head gasket if done correctly.

Sounds like a simple coolant leak near the rad, have you tried warming it up and simply looking around the Coolant system? Perhaps while revving the engine? That is where I would start.

fragmare

I wouldn't immediately jump to the conclusion of a head gasket issue on this. Pressurize the coolant system and pin down the leak location. Replace/repair whatever is leaking. Bada-bing.

theYBLEGAL

Like stated previous, clean it. Then I say, warm it up, then romp on it some to get it nice and toasty. Then see if your upper and lower radiator hoses are rock solid and look for leaks.

Jedi116

Yo, Jack.

I'm curious as to whether or not you've fixed your problem yet?
Is there any update?