Wtf! Lost 30 PSI in both rotors in less than a month!?
09-05-07, 12:14 PM
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Wtf! Lost 30 PSI in both rotors in less than a month!?
So I bought a JDM engine and put it in my car.
I had some problems starting the car ( bad gass but didn't know) so I tried the atf trick, didn't start either. So right after, I took a compression test and it showed 120 PSI on both rotors. I switched the gas the same day and it started right up. So the ATF didn't have time to eat any seals...well, not in 2 hours anyway.
Now just for fun, I took the compression this afternoon and it showed 92 PSI on both rotors. Why?
Is it because it had oil in the chamber and it showed higher compression or am I slowly killing my engine and dont know why?
I had some problems starting the car ( bad gass but didn't know) so I tried the atf trick, didn't start either. So right after, I took a compression test and it showed 120 PSI on both rotors. I switched the gas the same day and it started right up. So the ATF didn't have time to eat any seals...well, not in 2 hours anyway.
Now just for fun, I took the compression this afternoon and it showed 92 PSI on both rotors. Why?
Is it because it had oil in the chamber and it showed higher compression or am I slowly killing my engine and dont know why?
09-05-07, 12:29 PM
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Because its JDM yo!
Ok got that out. I think it is probably as you stated, the oil in the housings might have given a temporary higher number. But I am not sure. Is the engine cranking at the proper speed to get an accurate test?
Ok got that out. I think it is probably as you stated, the oil in the housings might have given a temporary higher number. But I am not sure. Is the engine cranking at the proper speed to get an accurate test?
09-05-07, 12:38 PM
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My starter turns just fine. And its the same starter I that I used when I first tested it.
Last edited by Aaron Cake; 09-05-07 at 12:52 PM. Reason: Merge two posts
09-05-07, 12:48 PM
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If its at 92, I'm not worried. 92 is pretty acceptable for a TII.
The compression test is supposed to be taken at 350rpm if I'm not mistaking. If the starter turns slower, you'll have lower compression readings.
Last edited by Aaron Cake; 09-05-07 at 12:51 PM. Reason: Merge two posts
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09-05-07, 12:50 PM
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Putting ATF or oil into the engine will cause the compression to rise due to better sealing. But the effect goes away as soon as the stuff burns off.
Compression tests are evil anyway. As long as the engine runs, makes good power and starts hot or cold, the compression is fine.
Compression tests are evil anyway. As long as the engine runs, makes good power and starts hot or cold, the compression is fine.
09-05-07, 01:31 PM
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As long as the engine runs, makes good power and starts hot or cold, the compression is fine
Numbers? who needs numbers?
09-05-07, 01:39 PM
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You don't have a compression issue if it runs good. When you DO have a compression issue or other "My car won't start" issue, the numbers are exactly what you DO need.But if everything is running, go drive it!
09-05-07, 01:55 PM
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make sure that you didnt do what my friend did.
Do the first test without having the throttle @ WOT, then do the second test @ WOT. There will be a difference.
Do the first test without having the throttle @ WOT, then do the second test @ WOT. There will be a difference.
09-05-07, 02:34 PM
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I wont, it still has +/- 120 PSI I'm sure of it. 
I just took the compression for fun to see what the difference between trailing and leading plugs would be...Then I pissed my self immediatly.
But now, since I know I'm a retard, I feel better.
Quote of the day.
I just took the compression for fun to see what the difference between trailing and leading plugs would be...Then I pissed my self immediatly.
But now, since I know I'm a retard, I feel better.
Quote of the day.
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