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Can I do a compression test by turning the engine by hand?

  • Thread starter Thread starter Notchbackdrew
  • Start date Start date Apr 15, 2006
N

Notchbackdrew

New Member
Mar 21, 2006
44
0
0
Apr 15, 2006
#1
  • Apr 15, 2006
  • #1
Simple enough question...I just want to turn the engine using the crank bolt. Is this possible or are the revolutions to slow/sporadic? Reason I ask is I have the headers off on one side and the tranny out... I couldnt get to one cylinder earlier because the header runner was in the way. I was curious if I could do a compression test by spinning the engine by hand.

Second question, earlier when I did a compression test I got about 128- 140 in all cylinders besides number 6 (its the cylinder I couldnt get to). The car hadnt been started in 3 days when running the test nor did I open the throttle plate. Is it reccomended I do this test again after warming up the engine, then opening up the throttle plate?

Please let me know.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
33
129
Apr 15, 2006
#2
  • Apr 15, 2006
  • #2
Your arms will probably fall off before you get anywhere doing this manually.

The main thing to look for is consistancy per testing session. As you noted, differences in methodology can yield different results. A hot motor is pretty important for getting somewhat accurate numbers, and propping the Throttle open helps, as does pulling all plugs and putting a charger on the battery.

Good luck.
 
N

Notchbackdrew

New Member
Mar 21, 2006
44
0
0
Apr 15, 2006
#3
  • Apr 15, 2006
  • #3
well I figure If I used a breaker bar?? no?
 

CRASH7772

Member
Apr 27, 2003
401
1
16
NH
Apr 15, 2006
#4
  • Apr 15, 2006
  • #4
Your engine needs to be warm...just unhook your coil wire from coil and cap and bump your ignition and make sure throttle is open when doing so. It would take a hour to do it your way.
 

green

New Member
Apr 26, 2003
291
0
0
Apr 16, 2006
#5
  • Apr 16, 2006
  • #5
nope
 

troyGT03

New Member
Feb 22, 2004
278
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0
too close to memphis,tn
Apr 16, 2006
#6
  • Apr 16, 2006
  • #6
no no no
 
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