5.8 Compression Test
Thread Starter
Senior Member
Joined: Jun 2012
Posts: 168
Likes: 0
From: Fort Myers, Florida
5.8 Compression Test
Hey guys,
My fiancée got a 96 Bronco from her grandpa, the thing is a rusty hunk of ****, but seems to run well. The idea is to pull the 5.8 out of it to replace the 5.0 that’s in my 95 F150, which hasn’t run right since I got it and I can’t seem to figure out why. Did a compression test on the 5.8 today, results below. Have conflicting opinions from my friends on if this needs a rebuild, thought I would see what yall think. 5.8 Compression test results
1: 165
2: 165
3: 165
4: 160
5: 175
6: 158
7: 157
8: 153
My fiancée got a 96 Bronco from her grandpa, the thing is a rusty hunk of ****, but seems to run well. The idea is to pull the 5.8 out of it to replace the 5.0 that’s in my 95 F150, which hasn’t run right since I got it and I can’t seem to figure out why. Did a compression test on the 5.8 today, results below. Have conflicting opinions from my friends on if this needs a rebuild, thought I would see what yall think. 5.8 Compression test results
1: 165
2: 165
3: 165
4: 160
5: 175
6: 158
7: 157
8: 153
Senior Member
Joined: Jul 2007
Posts: 3,806
Likes: 480
From: Cape Girardeau MO
Opinions and interpretations are gonna vary, but my two cents' -
Arguable guideline is 15%.
Highest compression == 175, and kinda suspicious since so far above the middlins of the rest - carbon buildup or other going on with that cylinder?
Lowest compression == 153
15% of 175 is 26.
175 - 26 == 149
Unless you're flush with cash or have aspirations for show-level restoration, my opinion is to call it good and roll with it, considering vehicles approaching 30 years old.
The next opportunity to excel would be what-all is involved with swapping different displacement motors, which is outside my sandbox of knowledge.
Arguable guideline is 15%.
Highest compression == 175, and kinda suspicious since so far above the middlins of the rest - carbon buildup or other going on with that cylinder?
Lowest compression == 153
15% of 175 is 26.
175 - 26 == 149
Unless you're flush with cash or have aspirations for show-level restoration, my opinion is to call it good and roll with it, considering vehicles approaching 30 years old.
The next opportunity to excel would be what-all is involved with swapping different displacement motors, which is outside my sandbox of knowledge.
Senior Member
Joined: Oct 2016
Posts: 3,705
Likes: 766
From: Parts Unknown
Hey guys,
My fiancée got a 96 Bronco from her grandpa, the thing is a rusty hunk of ****, but seems to run well. The idea is to pull the 5.8 out of it to replace the 5.0 that’s in my 95 F150, which hasn’t run right since I got it and I can’t seem to figure out why. Did a compression test on the 5.8 today, results below. Have conflicting opinions from my friends on if this needs a rebuild, thought I would see what yall think. 5.8 Compression test results
1: 165
2: 165
3: 165
4: 160
5: 175
6: 158
7: 157
8: 153
My fiancée got a 96 Bronco from her grandpa, the thing is a rusty hunk of ****, but seems to run well. The idea is to pull the 5.8 out of it to replace the 5.0 that’s in my 95 F150, which hasn’t run right since I got it and I can’t seem to figure out why. Did a compression test on the 5.8 today, results below. Have conflicting opinions from my friends on if this needs a rebuild, thought I would see what yall think. 5.8 Compression test results
1: 165
2: 165
3: 165
4: 160
5: 175
6: 158
7: 157
8: 153