S2000 Under The Hood S2000 Technical and Mechanical discussions.

Worried: Another low compression engine question

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Old Feb 14, 2014 | 03:09 AM
  #21  
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Originally Posted by leoxle
Sorry to bring back my old thread but I have the update. Finally got a valve adjustment done, and redid a compression test, this time with injectors unplugged as Billman said to do. Same similar results, 165, 165, 175, 177. Still very consistent, and low. Mechanic said the head seemed to be in good shape from what he saw during the valve adjustment. I guess its the bottom end then, perhaps it really is worn out rings. Yet the car runs very strong and no signs of bad rings or other. This isn't looking good
Perhaps you are looking for a problem that does not exist? Try finding another s2000 and use the same compression tester/methods and see if you get the same results. If the other s2000 is showing compression such as 210, 210, 215, 215 than you may want to look at why your numbers are so low. In the case where his/her numbers are the same that you now know that attitude, methods, tester, etc., are producing the low compression numbers. There is no point in ripping the engine out to find that nothing is wrong; especially if you see no codes, problems, oil lost, noises, etc. You can also get a leak down test performed. A leak down will tell you if the rings are worn or if the valves are bent/burnt better than a compression test. You should be able to pin point the problem, if there is one.
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Old Feb 14, 2014 | 05:53 AM
  #22  
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Originally Posted by Gotpepsi
Originally Posted by leoxle' timestamp='1392346840' post='23015007
Sorry to bring back my old thread but I have the update. Finally got a valve adjustment done, and redid a compression test, this time with injectors unplugged as Billman said to do. Same similar results, 165, 165, 175, 177. Still very consistent, and low. Mechanic said the head seemed to be in good shape from what he saw during the valve adjustment. I guess its the bottom end then, perhaps it really is worn out rings. Yet the car runs very strong and no signs of bad rings or other. This isn't looking good
Perhaps you are looking for a problem that does not exist? Try finding another s2000 and use the same compression tester/methods and see if you get the same results. If the other s2000 is showing compression such as 210, 210, 215, 215 than you may want to look at why your numbers are so low. In the case where his/her numbers are the same that you now know that attitude, methods, tester, etc., are producing the low compression numbers. There is no point in ripping the engine out to find that nothing is wrong; especially if you see no codes, problems, oil lost, noises, etc. You can also get a leak down test performed. A leak down will tell you if the rings are worn or if the valves are bent/burnt better than a compression test. You should be able to pin point the problem, if there is one.
Many people have said it might be a bad tester but I used two testers and both yielded the same results. But one of them wouldn't hold the number, needle would only move the the number during cranking then go down to zero. That was the first tester, then I went a bought a different one, and same numbers. And yeah the next step is a leak down test. Maybe that will give me some answers. I'd love for it to just be the testers and that nothing is actually wrong lol.
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Old Feb 14, 2014 | 07:41 AM
  #23  
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With the leak down test kit you can pinpoint where the air is escaping. That's if there's even a large enough percentage leak to merit looking. My guess is that you'll turn out fine. I highly doubt that all of your ring/ cyl walls could be bad, but who knows.

If you do have air escaping, simply pulling the oil pan an looking up you'll be able to partially see the cyl walls and area around the rings. A 3' or so length of hose to the ear is a great way to find air/vac leaks.
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Old Feb 14, 2014 | 07:43 AM
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The first tester you mentioned has a leak somewhere between the check valve and the gauge.
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Old Feb 14, 2014 | 09:04 AM
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Originally Posted by MR.T
With the leak down test kit you can pinpoint where the air is escaping. That's if there's even a large enough percentage leak to merit looking. My guess is that you'll turn out fine. I highly doubt that all of your ring/ cyl walls could be bad, but who knows.

If you do have air escaping, simply pulling the oil pan an looking up you'll be able to partially see the cyl walls and area around the rings. A 3' or so length of hose to the ear is a great way to find air/vac leaks.
Thank you for the info! I'll definitely do a leak down soon. And I pray that you're right,_ hope I'll be fine. Hard to believe that all the rings are bad with only 83,000 miles. I just need the engine to be fixed up by July, because that's when I plan to boost haha and I won't do it till the engine is healthy. I just seriously can't believe that the compression can be low when the car drives so well.
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Old Feb 14, 2014 | 05:46 PM
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http://youtu.be/WgrfT0LFMhc

This is a great vid. Look in the stickies to find the leak down test procedure on our Hondas. I think most just pull the vc to line up tdc.
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Old Feb 15, 2014 | 09:36 AM
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Originally Posted by MR.T
http://youtu.be/WgrfT0LFMhc

This is a great vid. Look in the stickies to find the leak down test procedure on our Hondas. I think most just pull the vc to line up tdc.
Thanks for the link, I think I've run across that video before. Once I do the leakdown, ill post another update about my findings. Fingers crossed.
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Old Feb 22, 2014 | 10:35 PM
  #28  
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Bringing my thread back AGAIN but I have more updates. Never got around to doing the leakdown test (was supposed to get it done this past week but couldn't get a hold of a tester) but I do have some good news. I was reading reviews on the compression tester I had been using, and just about EVERYONE who had used it complained about it having a bad design and that it reads much lower than other compression testers. Its the U.S. General compression tester, I bought it from Harbor Freight. That being said, I went to autozone and borrowed their OEM tester and I got:

210, 210, 210, 215

So MUCH higher than my previous numbers. Are those acceptable numbers? I'm just glad its not any lower, but should I be at all worried that its not any closer to 240? I might have been freaking out over nothing. I didn't know my tester was bad and I did use a different one before but I guess that one was bad as well lol.
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Old Feb 22, 2014 | 11:01 PM
  #29  
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Those numbers indicate a healthy engine. Nothing to worry about. Even a brand new car would not test at 240. Boost away without a worry.
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Old Feb 22, 2014 | 11:42 PM
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Originally Posted by Gotpepsi
Those numbers indicate a healthy engine. Nothing to worry about. Even a brand new car would not test at 240. Boost away without a worry.
Thanks I am so relieved to know that my engine is alright. Thought I would be rebuilding it haha. Such an unbelievable relief when it was something so simple.
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