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Discussion Starter #1
I did a compression test on the motor today and got some really weird numbers. I did everything by the book. I need yalls help. I do have piston slap. I have had it ever since this motor left the grace of Canada and was installed in my car. The car has a 11k miles on it and has over 12-13#s of boost on it on a decent fuel system thats seem some detonation. The car feels like its down on power sometimes and sometimes it runs like a bat out of hell. Tell me what yall think...

Compression Test Info

Test Done Turning Over while WOT until the gauge stayed at the same reading.

Passanger
1.) 145/155/160/165/160
2.) 175/190/185/185
3.) 200/200/200
4.) 220/225/225
5.) 165/185/190
6.) 145/150/150
7.) 170/170/170
8.) 175/180/180

This test was done as the same as above except I added a little bit of oil to each cylinder.

Passanger
1.) 210/200/180
2.) 250/220/198
3.) 270/250/240
4.) 280/260/240
5.) 260/250/240
6.) 210/180/180
7.) 240/220/205
8.) 230/210/200
 

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Discussion Starter #2
tttt
 

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Adding oil to the cylinder tends to coat the rings and give you a higher reading. I say you have bad rings in #6 cyl but it shouldn't be anything that would give you a noticeable loss of power.....
 

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Really.He has bad rings with only 11k. I just traded my Chevy berretta with the 3.1 v6 in it that had 142k on it an at 140k i had it in the dealer and they where amazed at the motor. They said it had like new compression and asked if i ever had that motor rebuilt and i said no. With 11k and haveing bad rings i would be mad. I hope my ford holds up as good as that car did.
 

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Discussion Starter #5
One thing to remember is that I do make 500rwhp and the motor is built and it has a blower lol. So if this were a stock car and it was doing this I would be pissed!!! :)
 

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chris, I saw your IM last night and during my response (which btw, was "I don't know" :D ), my latop took a dump.. :(

sorry
 

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Oh i see that now. I didnt look at your sig before. I thought would be strange if it were stock like i thought. I was already starting to worry about my car when i read that lol.
 

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if you read the manual it will tell you how to deciefer the readings. on the first test #3 didn't go up or down. your suppose to build. that may have been an error on you. when i did mine a year ago the first stroke always started out at 150 and the max difference was a low cylinder of 170 and i high of 185. the manual says , if i recall right, that there should be no more than 10 psi difference between two cylinders.the way your compression goes down after the oil is some what normal. even a brand new motor will have blowby.off of the first test i would say you have a cracked head gasket between 6&7. and most likely the number one. does you car overheat at all, or use a lot of water?
 

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Discussion Starter #9
ttt
 

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Discussion Starter #10
The car isnt overheating. And Im not losing any water. I thought the same thing but Im not seeing any of those symptoms..
 
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