CptHMCrunch

H22A is currently losing coolant. I do not think it is a head gasket leak. Motor was rebuilt. Rod bearings, rings, valve job, stem seals, new head gasket, etc. Motor has ~700 miles after rebuild. The motor passed leak down with ~9% on each cylinder after first cool/warm cycle following rebuild. No rise in coolant level or bubbling with leak down. Vehicle needs a very slight topping off each day. All coolant hoses have been replaced. Here is information

1. Engine loses small amount of coolant each day.

2. The overflow tank NEVER receives coolant from the cooling system. If the overflow tank is at the minimum line, it will remain at the minimum line under ALL driving conditions and through all normal operating temperatures.

3. Radiator caps is new.

4. Upper radiator hose can be squeezed ~1/2 way closed at full operating temperature. Pressure in upper radiator hose feels about right.

5. Thermostat is functional by visual observation of change in coolant flow during warm up cycle.

6. Water pump is new and functional.

7. Vehicle does not overheat.

8. Inspection has been done at all hose clamp locations by feeling for coolant and/or scaling deposits from evaporating coolant. Possible leakage found.

9. Inspection has been done at both ends of water pipe for leakage.

10. Inspected line from radiator to overflow tank for cracks, found nothing.

I am beginning to suspect that there is a pinhole leak in the radiator, blow by at one of the hose clamps, or leakage at a rubber o-ring style gasket somewhere. I do not suspect a blown head gasket because it is brand new, I have never failed to successfully replace a head gasket, the coolant system is not being pressurized, and the overflow receives no coolant. The vehicle is currently going through a slight warm/cool cycle with cardboard under it. All hoses were thoroughly wiped clean and will be reinspected after the cool down.

Has anyone experienced coolant loss with similar symptoms or under similar circumstances? Any input would be greatly appreciated.

snobordboy

Maybe just slowly working out small bubbles in the system. Was it bled while at a slight angle through 2 full fan cycles? Heat turned all the way up?

ef2_civic

iTrader: (1)

Hose clamps could be it or heater core too.

holmesnmanny

Could be heater core. You will smell coolant vapor coming out of the vents with heater **** on red and blower on.

minilogoguy18

If there is no visible leak and you're definitle losing coolant no matter how much you.may not want to think so that head gasket could have a small leak. It won't run hot if it's small, maybe just a barely noticeable misfire. Quit guessing and put a coolant system tester on it or even just run it with a radiator funnel on it Hal filled, if it bubbles steadily at operating temp then the headgasket is leaking

CptHMCrunch

If the head gasket was leaking the overflow tank would be getting filled. If combustion gases were entering the cooling system and displacing a volume of fluid then the volume of fluid being displaced would have to go somewhere. The only two places it could go would be in the overflow or out an external leak. I'm fairly confident that if I had an external leak that was so severe it was able to compensate, in full, for the additional volume added by combustion gases then I would be able to notice significant leakage. The external leak would have to be expelling the coolant at the same rate that combustion gas was entering the system and the operating pressure would have to remain below the pressure which opens the radiator cap in order for the overflow to experience no increase in coolant level. Furthermore, such an extreme external leak would most likely be leaking while cold and at minimal pressure. Finally, lack of a visible external leak is no indication that the head gasket is blown. Consider the case of an external leak at or near a very hot portion of the motor. Is it possible that the head gasket is blown? Sure it is possible. Is it likely considering the nature of the coolant loss? Not really.

Anyway, I had to send it to the shop because I am living half way across the country right now. Sent it to some very knowledage guys. The OEM style hose clamp was allowing the lower radiator hose to leak when pressurized. The shop told me that it was "leaking pretty good" and not holding pressure. Hose clamp was replaced and the system is now holding pressure.

holmesnmanny

You are completely wrong about your theory about coolant leaking into the cylinder but clearly you know more than us so you must be right.

CptHMCrunch

Support your claim by identifying and refuting anything I have said that is incorrect. This should be fairly easy considering that I am "completely" wrong.

I'll give you one right now though. The coolant could be getting burned by being sucked into the combustion chamber. This would be the third possible source of coolant loss. So the coolant would not necessarily have to be expelled through an external leak or to the overflow at the same rate that combustion gases are entering the cooling system. If this were the case, the head gasket leak would have to be severe. The highest pressure occurs during the combustion stroke, so we can assume that combustion gases will only be expelled from the chamber during combustion. Neglecting kinetic energy, the combustion stroke must have greater pressure than the compression stroke or the piston would stop half way through the compression stroke and reverse its path of travel. Coolant would not leak into the cylinder during the compression stroke because the gases in the cylinder want to move towards equilibrium. Assuming that the leak is not severe, the gas/air mixture would leak into the cooling system. Assuming that the motor was designed to experience minimal internal resistance to the power generation process, the exhaust and intake strokes will be steady state. At steady state there will be no coolant leak into the combustion chamber unless the leak is severe. If not at steady state then the exhaust stroke will build pressure, once again the gases will be expelled into the cooling system. If not at steady state then the intake stroke will generate vacuum. So, the intake stroke will be the only possible stroke that is sucking coolant into the combustion chamber. Considering the position of the valves during each stroke you will see that, if a leak exists and it is not severe, more gas will enter the coolant system than coolant entering the combustion chamber. That being said, I stand by my original hypothesis. For the cooling system to lose coolant without experiencing any increase in the level of coolant in the overflow, the coolant displacement would have to occur through an external leak at, or near, the same rate that combustion gases enter the coolant system. Furthermore, the coolant system would have to remain at a pressure below the pressure which opens the radiator cap. If the coolant system reached a higher pressure the coolant level in the overflow tank would increase because the cap would open allowing coolant to enter the tank.

Making claims that someone is completely wrong without giving any reason or providing supporting evidence does nothing to increase the collective knowledge of the community. All it does is serve the purpose of convoluting the discussion and putting doubt into the mind of those seeking to diagnose problems. This is one of the largest problems I have found with tech-talk on the internet.

I'm not saying that the head gasket is 100% good, but I am saying that it seems highly unlikely considering the good leak down and other supporting information I have. It is a possibility, and I will not rule it out as a possibility until the issue is fully resolved or the head gasket leak is verified.

Also, I didn't say anything about coolant leaking into the cylinder during my initial post.

I forgot to mention in my previous post that the upper radiator hose was also leaking. This could account for the coolant level decreasing without drawing coolant from the overflow. Coolant out the lower hose, air in the upper hose. I'll post an update on the issue when my girl gets the car back next week and tells me whats going on with it.

*Edit* to add coolant loss into cylinder discussion and additional information on the pressure test results.

holmesnmanny

When a head starts leaking due to a warped head coolant gases do escape into the coolant but that can be equally offset by coolant leaking back into the combustion chamber. Not all head gasket leaks have overflowing reservoirs. I know by experience.

CptHMCrunch

I agree, severe leakage due to warped/cracked cylinder head does not always cause the overflow tank to fill. However, there is no cracking or warping in this situation. Before you start making wild accusations that someone is "completely" wrong, you should be sure to read and understand the context of the post. Your argument that warped and cracked heads exhibit leakage refutes nothing when considering the context of my post.

Anyway, I don't want to get in a flame war so let us just agree that the cylinder head is a possibility.

holmesnmanny

This was your very first comment in response to someone that is really quite knowledgeable about cars here. You were basically telling him what the deal was, but this comment in itself is completely wrong.

Furthermore that comment summarizes the rest of your post. Since that's the case, your post is completely wrong.

You originally asked for opinions and yet when you got one you completely cast it aside.

While it is possible for some leaking head gaskets to blow bubbles back into the reservoir, it's hardly always the case.

CptHMCrunch

The statement doesn't summarize the rest of my post. The part of the post that follows the statement is an argument to support my claim that the head gasket is unlikely, it is, literally, not a summary. Also, how would a "summary" of my own comment prove my comment wrong?

If he is so knowledgeable then how would his comment about using a funnel that is partially filled with coolant to look for bubbles support the argument that the head gasket can leak without expelling gases into the overflow tank? His suggested method of looking for gases in the cooling system actually supports my claim. If gases are being expelled (they are visible as bubbles in the coolant), then a volume of coolant is being displaced, and that volume of coolant must be displaced somewhere.

You haven't provided any evidence or suggestions that my model is wrong. Adding additional words to the phrase "you're wrong" does not support your claim.

mike_1212

I have personally seen slight coolant loss in many vehicles.... I have seen instances in which a ccracked/warped head is the cause without misfires and without exhaust gasses entering the coolant. Have seen this with cracked cylinder walls as well.. and have even seen this with bad headgaskets.. alot of times a blown head gasket goes undetected in these circumstances due to lack of other symptoms comonly attributed to a bad head gasket...if your leak has been solved by a new hose clamp, then be happy that the problem is solved and stop arguing about who right or wrong.. we are all wrong from time to time.. why? Cause we are human.... imperfect machines building and diagnosing imperfect machines... but op you have the benefit of seeing the symtoms in-person... wheraz we read what you type and decipher what you mean... if the problem is fixed then just be happy it wsn't something more serious or costly than a couple clamps

holmesnmanny

My previous post describes how you are wrong however you can't correct a scoffer so theres no point trying.

CptHMCrunch

http://www.jimpryor.net/teaching/vocab/validity.html

Anyway, I knew that it wasn't a cracked/warped head because I had the head off and did a thorough inspection. The valves were cut and the head was thoroughly cleaned and inspected by a machinist and myself. The pistons also came out and the cylinder walls were thoroughly inspected and measured by an engine builder and myself.

holmesnmanny

My grammar and english composition would run circles around you. I'm not here to teach you english 'though. Most of the time I'm posting on mobile and don't even put sentences together at all.

You would best be served in the future not asking questions you think you already know the answer to, especially if you're not really valuing any meaningful input.

CptHMCrunch

The link doesn't have anything to do with grammar or composition. It has to do with forming an argument. The sentence "Furthermore that comment summarizes the rest of your post. Since that's the case, your post is completely wrong." literally makes no sense. It doesn't demonstrate that my post is wrong. The conclusion you make does not follow from the premise. There is nothing that links a summary to a false statement. Your argument is the equivalent of me saying "You are a human. So you own a dog." Also, if your composition was so exquisite then you would not have included "at all" in your third sentence and you would have capitalized English.

To assume that your composition and grammar skills would "run circles around me" just goes to show that you are pretentious.

I have no idea where you got the idea that I already knew the answer. Eliminating a possibility does not equate to finding a solution.

The input about the head gasket wasn't meaningful. The other input was meaningful, which is why I did not take issue with it. I was looking for suggestions, but that suggestion does not make sense given the situation. I have shown that the suggestion does not make sense. The idea that it can leak due to a warped head is invalidated by my first post which contains the description of the work done on the motor.

Don't worry, it's okay. I'm not mad at you.