Engine skip/bucking
Junior Member
Joined: Jun 2009
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2002 ford f150 4.6l v8 cylinder 5 low on compression
Started truck on morning, service engine light came on, engine started running a little rough and missing, some power drain. 71,000 miles on engine. Changed fuel filter, didn't fix, took it to a local shop, they checked cylinder 5 based on p305, said it was low on compression, suggested rebuilding the engine. I checked it on on the web. Found identical problem that i was having and the suggestion was to change spark plugs and coil pack. Called the mechanic back, he said it wouldn't make a difference when it comes to compression. I went somewhere else, changed coil pack and spark plugs. Fixed problem. The bill went from $2,000 to $146.00.
Technical Article Contributor
Joined: Oct 2005
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From: MI
Started truck on morning, service engine light came on, engine started running a little rough and missing, some power drain. 71,000 miles on engine. Changed fuel filter, didn't fix, took it to a local shop, they checked cylinder 5 based on p305, said it was low on compression, suggested rebuilding the engine. I checked it on on the web. Found identical problem that i was having and the suggestion was to change spark plugs and coil pack. Called the mechanic back, he said it wouldn't make a difference when it comes to compression. I went somewhere else, changed coil pack and spark plugs. Fixed problem. The bill went from $2,000 to $146.00.
Well, someone was wrong
Last edited by jbrew; Jun 19, 2009 at 10:45 AM.
Technical Article Contributor
Joined: Oct 2005
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From: MI
If you have a print-out of what they found to determine. We could tell yuh.
A read of all eight would be best, but if you have the numbers for just one,- depending on what it is, we might be able help.
A read of all eight would be best, but if you have the numbers for just one,- depending on what it is, we might be able help.
Junior Member
Joined: Jun 2009
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Your right. We checked compression again and there was plenty of compression to make the cylinder fire. Maybe the other guys instrument was off?
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We cross-checked with the other cylinders (even after we checked the compression on the cylinder that was "low" on compression and found out it wasn't) and everything checked out. I didn't realize each engine kind of has it's own compression "signature". Thanks.
Technical Article Contributor
Joined: Oct 2005
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From: MI
http://www.aa1car.com/library/compression.htm
Test warm if possible, - more accurate.
Senior Member
Joined: Mar 2008
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From: Central New York
Here's a general -
http://www.aa1car.com/library/compression.htm
Test warm if possible, - more accurate.
http://www.aa1car.com/library/compression.htm
Test warm if possible, - more accurate.
Good Job, Thanks....
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
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From: MI
Hey!- it's right, even the #'s.
______________________________
Damn!!! That is a good link!! I went back
Last edited by jbrew; Jun 22, 2009 at 05:51 PM.
Senior Member
Joined: Mar 2008
Posts: 835
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From: Central New York
Damn!!! That is a good link!! I went back [/QUOTE]
You kill me
How you been man. Going on Vacation starting Sat. I'll have my son's laptop with me so I can check in now and then. Behave yourself while I'm gone !
[/QUOTE] You kill me How you been man. Going on Vacation starting Sat. I'll have my son's laptop with me so I can check in now and then. Behave yourself while I'm gone !