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DISCUSSION => Engine + Driveline => Topic started by: B318M42W on January 05, 2009, 09:58:17 AM

Title: compressions
Post by: B318M42W on January 05, 2009, 09:58:17 AM

hey everyone! i'm lost right now. I did 2 compression test and the # d'ont match. first test: 205-215-215-210 done cold. second test done hot: 165-195-190-175. I don't know what to think about it and i'm basing part my descion on whether to sell or not on this test.  

Thanks for any input!

Title: compressions
Post by: Sophia69IS on January 05, 2009, 10:12:50 AM

You mean that you don't know which test is accurate? Because I know that you are supposed to run your compression tests after the engine is at running temp. So I would go with the second one.

Title: compressions
Post by: KenC on January 05, 2009, 10:20:54 AM

165 is on the cusp of being too low for combustion.  I'd put a tiny bit of oil in that cyl, manually crank the engine a few times and retest it.  If it goes up significantly, your rings are a little worn.

Also, you have your fuel pump relay and/or fuse out during this too, right?  Wash-down could be giving you some low readings, not to mention score your cylinder walls.

Title: compressions
Post by: B318M42W on January 05, 2009, 11:11:46 AM

thanks! i'll try a re-test without any cool-down time (it had a chance to cool down a little before testing). and yeah, the fuel relay was out.

Title: compressions
Post by: B318M42W on January 06, 2009, 03:18:57 PM

the results are in! heres the new test: 207-202-202-207. WAY better than the last one! while waiting for it to heat up, I took a video of the engine. anyone has any ideas why it has somesort of cyclic sound and vibration (near the end)?

http://s729.photobucket.com/albums/ww298/B318M42W/?action=view¤t=100_3823.flv
http://s729.photobucket.com/albums/ww298/B318M42W/?action=view¤t=100_3822.flv

thanks again for any input!

Title: compressions
Post by: B318M42W on January 14, 2009, 05:04:39 PM

bump

Title: compressions
Post by: xwill112x on January 14, 2009, 08:42:47 PM

how many miles?


have you changed the tensioner?

Title: compressions
Post by: bbarnumboy on January 14, 2009, 10:48:40 PM

anyone know what the stock recommended compression is ?

Title: compressions
Post by: KenC on January 14, 2009, 11:41:59 PM

Quote from: bbarnumboy;64700

anyone know what the stock recommended compression is ?

~200-210 I believe

Title: compressions
Post by: B318M42W on January 15, 2009, 04:19:36 PM

the tensioner has been changed, has 170 000 original miles and stock compressions i beleive is 225 psi

Title: compressions
Post by: bbarnumboy on January 15, 2009, 10:41:40 PM

ok cool i will have to check mine. it is at 190,000 miles and i changed the tensioner about 15,000 miles ago