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The car I am working on is my brothers 94 Civic LX 1.5 d15b7 all stock.

It is burning coolant- I pulled all the spark plugs, cyl 1 was very wet, 2,3 and 4 are dry. There is no coolant in the oil.

The results to a compression test are Cyl 1= 190 Cyl 2= 190. Cyl 3= 200 Cyl 4 = 200

I changed the intake gasket- no change.

I did a leak down test on cyl 1. With 100psi it leaked down to 95 psi in 18 minutes.

Everything seems to test out fine for me. My last thought is if it's possible could there be a crack in the head somewhere along the valve guide allowing the coolant into the cylinder but still giving me good compression and leak down test?

Any other ideas before I pull the head off?

Thanks in advance for any input!

 
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I don't know what you did here, but it makes zero sense.


#1 plug was very wet with what substance?

If coolant, the usual and expected problem is a blown head gasket.

 
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I don't have a legitimate leak down tester so what I did was apply 100psi to the cylinder, hoping that air would leak back through where the coolant is getting in. There was next to no leakage. Does it make sense it's the head gasket when my compression is still at 190?

 
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So is the plug wet with coolant?
Head gasket is THE logical item that coolant can and will breach.


You don't need a leakdown tester.
You don't have compression loss, therefore you don't need to check cylinder leakage.
EDIT: A leakdown test is used AFTER a compression test reveals a compression fault. It is used to compare leakage rates of all cylinders.
You are wanting to force a leak, to expose the leak. You need a different method.





You have a coolant leak into a cylinder. (Right? You never said this is coolant.)

Use a radiator pressure tester:
Apply 15 PSI to the radiator, remove the spark plugs (and disable the distributor so you don't fry the coil), and wait.
Let it sit overnight if need be, with pressure on the radiator.
(If the pressure drops off right away.....you can probably skip leaving pressure on it overnight.)

Have someone crank the engine over while you watch and see what comes out of the spark plug holes.
Protip: Don't stand in front of the engine when you do this.





Conversely..... I use this on all 7th gens:
Set the suspect cylinder to TDC - (compression)
Remove the radiator cap, fill to the bottom edge of the radiator neck.
Apply 170 PSI air pressure (or however much pressure your compressor can give) to that suspect cylinder.
Watch for movement of the coolant level in the neck of the radiator.

 
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All cylinders leak through the rings.
I still can't figure out what you were doing here.

 
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Yes the plug is wet with coolant. When you pull the plug and turn the engine over coolant sprays out the spark plug hole.

 
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This morning I filled the coolant- #1 cylinder to TDC and applied 170 psi to the cylinder through the spark plug hole. No bubbles or Change in coolant level.

 
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Pull the head off.
Inspect the head gasket and head/deck surfaces once you have the head off.

 
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I hope this means you filled the radiator with coolant, not the cylinder.


Were you filling the cylinder with coolant.........?

 
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I can't tell if you're trying to insult my intelligence or not.

 
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Not TRYING to, but I've been told I do it.
Were you insulted?


I only have your typed words to read.
I'm a very technical person, and I tend to take things I read very literally.

I don't know you, I don't know how much you do or don't know about cars and mechanical things.

I work with people that would have you believe they are the greatest wrench spinners in the world, but in reality I wouldn't trust them to install a damn windshield wiper correctly.


There are a few things unanswered in this thread.

I couldn't figure out what in the world you could be doing to give results of
I did a leak down test on cyl 1. With 100psi it leaked down to 95 psi in 18 minutes.
I still have absolutely no clue how you could come up with that,
and you have not explained what in the world you are doing to come up with this answer.
Whatever it is, this is not an answer that should come from a cylinder leakage test as I know it.

You STILL haven't bothered to explain this, I was trying to think of how anyone could come up with an answer such as you have there........


Then you posted
I filled the coolant- #1 cylinder...
And it dawned on me that filling the cylinder with coolant might cause the answer you have that I can't figure out.
See how you typed that? I can't read your mind, I can't tell what you meant.

Care to explain yet?



So....did you pull the head off yet? What did you find?
Is the head warped? Gasket blown out?

 
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I guess I can see how you could get that from that. I will try to be more specific.

It should have said- "I filled the coolant up at the radiator until level with the bottom of the radiator neck."
"I put cylinder #1 to TDC."

I did not pour coolant down the spark plug hole.

Sorry for the confusion. I don't have a computer or wifi and so all this is off my phone and this forum isn't very mobile friendly so it's difficult to go into great detail. My bad.

Due to the lack of having a leak down tester- what I did was put a shut off valve and an air guage in that order connected to the cylinder. Opened the valve and let 100 PSI into the cylinder and then closed the valve trapping that air in there. It took 18 minutes to lose 5 PSI which tells you nothing is leaking by. The results of this tell me the same thing as the test you suggested with 170 PSI. Even with 170PSI it was not letting air past.

I have done the testing and according to specs cylinder #1 is in good shape.

What I was really looking for is an answer to my original question. Is it possible that the head is cracked from the coolant passage to the valve guide which is the only way I figure coolant can be leaking outside the compression area yet still get into the cylinder, but not be in the oil. Or maybe I'm completely wrong and there's another way I have not considered the coolant could get in besides the usually cracked block/head or head gasket which the majority of the time will show in compression test.

I have not pulled the head yet. Too much on my plate at the moment.

 
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Thanks for understanding.
I already knew you didn't.


Wow. Just wow. I guess I see how you came up with what you did.

The length of time to see a pressure drop will be directly related to the volume of air trapped between the valve and the engine cylinder, therefore it is not good for producing any acceptable numerical test result. But it should have been ok for locating where a leak is going to, IF you can get it to leak. That's why I use full shop air line pressure when I need to see where a leak is going.


No it's not.
You are getting coolant into it.
You haven't performed the right test yet.

Possible, sure. Almost anything is possible.
But not bloody likely.
It's certainly not a usual failure on a Honda.

Not usual. Not here.
Your assumption of "majority" is absolutely incorrect. I'd venture to say it's an absolute rarity nowadays, especially with the use of MLS head gaskets.

A compression loss is only related to like one type of failure, and it would have to be a huge failure.

You cannot rely solely on a compression test for this. A compression test only checks one thing: Compression. And you still have plenty of it.

A head gasket can fail in any of several different ways (a dozen or more). It must seal at least 5 different areas away from each other.
Testing requires knowledge of several different test methods that may address each of the various possible failures.
Then you must choose the appropriate test(s) that will reveal the observed and suspected failure.


You are getting a plug wet with coolant.
You have coolant leaking INTO a cylinder.
Focus on that.
Pressurize the cooling system to force the leak to exhibit itself.

Observe safety precautions, never open the cap of a pressurized hot radiator!
Start with the engine at operating temperature (important),
shut it off,
put the pressure tester on the radiator and pump it up to 16 or whatever the max safe pressure is.

Remove the plugs.

Pressure will naturally drop as the engine cools down. Keep pumping pressure on it if you have to until you find coolant in the cylinder.

Now get a borescope ($$$) to see where the fluid is entering, or pull the head off to see if you can see why.




There's a "most likely" answer, and there are "not bloody likely" answers.
Choose wisely, grasshopper.


/Occams razor

 
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in my experience, if a cylinder is burning coolant the spark plug will be grey in color, a "wet" spark plug normally means the plug is not firing at all

 
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As in "drowning in coolant".

 
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HEY WAIT A MINUTE

I see the problem here.
All cylinders must leak, and yours isn't!

You need to remove the Schrader valve from your compression tester hose in order to let the air pressure get into the cylinder.





When you redo the check this time, remove the radiator cap first. You should have a geyser.

==========================


One more thing:
If you think this, you can do the radiator pressure test with the #1 cyl valves closed. If there is leakage from where you are talking about, the coolant should sit on top of the valves until you spin the engine over. Once the valve(s) open, the coolant would be 'drained' into the cylinder.