Compression problems?

2002 HONDA CIVIC
150,000 MILES • 1.6L • 4 CYL • 2WD • MANUAL
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RICHARD OAKS
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  • 3 POSTS
cylinders 1 and 4 have little or no compression. cylinders 2 and 3 have 180 PSI. cylinder 1 has 10 PSI and cylinder 4 has maybe 5 PSI. The engine cranks but runs badly. checked spark and fuel it was good. checked timing marks seem to be in line.
Feb 25, 2023 at 4:11 AM
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JACOBANDNICKOLAS
  • Experienced Mechanic
  • 110,240 POSTS
Hi,

Did this happen all at once? For the compression to be that low, either we have a valve that isn't fully closing, a small hole in the top of the piston, a failed head gasket, something is cracked, or a timing issue.

Have you removed the valve cover? If so, do all valves appear to be fully closing? Let me know.

Also, let me know how much you have already taken apart. We will likely need to remove the cylinder head for inspection. However, I need to know if it happened all at once, if there was any engine noise prior, or anything you can think of that may help. Keep in mind all Honda engines except the 3.0 and 3.2 are interference engines. If the timing belt jumped, we could have internal damage.

Let me know.

Joe
Feb 25, 2023 at 2:52 PM
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RICHARD OAKS
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Yes, it just started running rough. I have pulled the valve cover off,the upper timing cover, alternator, power steering, and A/C belts. removed harmonic balancer, all that to check if the timing marks lining up. No engine noise and still cranks and runs on the 2 cylinders. Just no power and of course runs like crap. All valves appear to be opening and closing.
Feb 26, 2023 at 2:19 AM
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RICHARD OAKS
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It's a 2000 not a 2002.
Feb 26, 2023 at 2:21 AM
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JACOBANDNICKOLAS
  • Experienced Mechanic
  • 110,240 POSTS
Hi,

It's odd that the cylinders are on opposite sides of the engine. By chance, did you notice low coolant? I'm questioning if coolant entered the two affected cylinders and slightly bent a connecting rod.

When you check compression, how long does it take for the compression to drop off in the low cylinders? I realize you aren't starting with much, but see if that drops quickly.

I attached the timing marks below that I have to confirm that is what you are seeing. If it is and you see the valves opening and closing, the head will have to come off.

Let me know.

Joe
Feb 26, 2023 at 12:06 PM
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