Rep Power: 0

Hello,

I have a 2005 Civic, 1.7 Liter SOHC engine. I replaced my head gasket this last weekend (third time - second time on this car). Everything was going really smoothly until I went to start the car for the first time. It idled high and was rough. I quickly identified cylinder 3 as not being affected by removing the coil pack. I did a compression test this morning and found no compression. I mean zero in piston 3. Below are my compression levels.

1 - 190
2 - 210
3 - 0
4 - 215

Any thoughts on why my compression could be zero at just cylinder 3? If the head was not tightened properly I would think this would affect the compression levels of the cylinders to the left and right of cylinder 3 to some degree. My valve lashes at cylinder 3 are within spec. I will be pulling the pan and checking the crank this evening.

Thanks in advance.

 
Rep Power: 222

Leak down test to see where it's going

 
Rep Power: 210

Did you do a compression test on all cylinders before removing the head?

Put a tablespoon of oil in that cylinder and retry the compression test. Also, follow Colin's suggestion for a leak-down test
Read the No compression in one cylinder in this link: https://www.2carpros.com/articles/th...ow-compression

 
Rep Power: 367

my best guess would be valve

 
Rep Power: 224

Same. Maybe one got bent/damaged while the head was off.

 
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Thanks for suggestions. So the verdict is in and I'm a complete moron. There is air coming out of the intake. I wanted avoid having to take off the harmonic balancer and thought I might be able to force the timing belt back on after I installed the rocker arms. Everything was lined up where it was when I took it off but when I couldn't get the belt back on I had to resort to pulling the balancer and doing the timing properly. The problem was that I had already installed the rocker arms and so the valve on cylinder three must have been protruding out. When I turned the crankshaft to set the timing I probably made contact with the valve and bent it. I didn't realize this was an interference engine. Just dumb. I went nice and slow, took my time, tried to be methodical, and one mistake created several more.

I'm pulling the head today and will be inspecting all four valves on cylinder 3 and probably take a peak at cylinder 1 to see if the reading of 190 is due to any distortion of those valves as well.

 
Rep Power: 512

Ouuuuuccccccchhhhhhhhhhhh

Glad you got it figured out though. Lesson learned, right?

If I had my D17 parts laying around still, I'd send some valves your way for admitting your mistake. I had a full set of, albeit used, D17A2 valves laying around in pretty good condition. If they haven't been tossed, they're probably floating around in my dad's garage somewhere. lol

 
Rep Power: 210

I also admire when people admit a mistake because we all make them occasionally. Most people seem to just leave and not reply again when it turns out they were the cause of a problem. Hopefully, things will go smooth for you from this point on.

 
Rep Power: 367

ouch!

 
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The suggestions on this forum helped identify the issue, so thanks to all of you for that. Yes, most definitely lesson learned. There is a right way and a sloppy/shortcut way to do things. With any luck I'll learn from this experience and it will be applicable to matters of auto repair and life in general.

The heads off and interestingly there only seems to be one intake valve out of the two that is bent. I did the light test (light in the intake passage). I'll be getting some brake cleaner and doing a liquid leak test on all cylinders as well. Would it make sense that only on of the two intake valves in cylinder three would be bent? I would assume they both would be coming down at the same time. Should I replace both just to be safe?

 
Rep Power: 367

i would do a complete overhaul of the head at this point.
Valve stem seals, replace the obviously bent one and check the other valves

 
Rep Power: 224

Yes. Only one intake valve fully opens during normal operation, the other only partially does. When VTEC is engaged the other begins to fully open.

 
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that is when i got confused.
the exhaust valve acts that way, not the intake.

 
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It keeps one intake valve mostly closed to promote swirling, better mixing the fuel/air for economy purposes. When VTEC is engaged it begins opening the second intake valve for more power.

 
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revising...
i keep remembering the old motorcycle engines that had 3 valves, 2 intake and one exhaust.
yeah, VTEC-E keep one intake valve almost closed in low RPM.
sorry for confusion...

 
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Would the valves act in the same manner in a non-V tech engine? One fully open and one partially open. To promote swirling?

 
Rep Power: 224

I believe so. The second intake valve is just never fully opened.

 
Rep Power: 210

Agree.

If the head is still off here's a video showing a test for leaking valves: