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c10hevy · 10-02-2011, 10:29 PM

In my 66 GMC I did a compression test today because it would stall out many times when starting in 1st gear. The results:
#1: 90psi
#2: 85 psi
#3: 75 psi
#4: 120psi
#5: 120psi
#6: 120psi

I was thinking the rings are leaking in the first 3 cylinders but after doing some searching ive found that it could possibly be from stuck valves or possibly even flattening of the camshaft.

Any help would be greatly appreciated.

10-02-2011, 10:29 PM	#1
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	#1 #2 #3 low compression in L6 250 In my 66 GMC I did a compression test today because it would stall out many times when starting in 1st gear. The results: #1: 90psi #2: 85 psi #3: 75 psi #4: 120psi #5: 120psi #6: 120psi I was thinking the rings are leaking in the first 3 cylinders but after doing some searching ive found that it could possibly be from stuck valves or possibly even flattening of the camshaft. Any help would be greatly appreciated.