Compression test results, not good, now what
Thread Starter
Melting Slicks
Joined: Aug 2006
Posts: 2,475
Likes: 97
From: KY/TN
St. Jude Donor '13-'14-'15-'16
Compression test results, not good, now what
Well I finally got around to replacing the plugs. I figured what the hell, would be good to take a look at them at 62K, and do a compression test while I am in there. Well here are the results.
#1 190 #2 200
#3 190 #4 200
#5 187 #6 190
#7 190 #8 145 (dry) 150 (wet)
Well it is obvious that there is a problem with the #8 cylinder. I added a little oil to the #8 cylinder and the pressure only came up a little so I know there must be a leaking valve.
So, where do I go from here? Is there a way to confirm my diagnosis, perhaps a 5 gas analyzer, or do I need a valve job?
#1 190 #2 200
#3 190 #4 200
#5 187 #6 190
#7 190 #8 145 (dry) 150 (wet)
Well it is obvious that there is a problem with the #8 cylinder. I added a little oil to the #8 cylinder and the pressure only came up a little so I know there must be a leaking valve.
So, where do I go from here? Is there a way to confirm my diagnosis, perhaps a 5 gas analyzer, or do I need a valve job?
Thread Starter
Melting Slicks
Joined: Aug 2006
Posts: 2,475
Likes: 97
From: KY/TN
St. Jude Donor '13-'14-'15-'16
Burning Brakes
Joined: Nov 2006
Posts: 1,071
Likes: 0
From: Goose Creek SC
Well I finally got around to replacing the plugs. I figured what the hell, would be good to take a look at them at 62K, and do a compression test while I am in there. Well here are the results.
#1 190 #2 200
#3 190 #4 200
#5 187 #6 190
#7 190 #8 145 (dry) 150 (wet)
Well it is obvious that there is a problem with the #8 cylinder. I added a little oil to the #8 cylinder and the pressure only came up a little so I know there must be a leaking valve.
So, where do I go from here? Is there a way to confirm my diagnosis, perhaps a 5 gas analyzer, or do I need a valve job?
#1 190 #2 200
#3 190 #4 200
#5 187 #6 190
#7 190 #8 145 (dry) 150 (wet)
Well it is obvious that there is a problem with the #8 cylinder. I added a little oil to the #8 cylinder and the pressure only came up a little so I know there must be a leaking valve.
So, where do I go from here? Is there a way to confirm my diagnosis, perhaps a 5 gas analyzer, or do I need a valve job?
Hammer
Banned Scam/Spammer
Joined: Jul 2006
Posts: 2,911
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From: Simi Valley CA
Safety Car
Joined: Jan 2005
Posts: 3,896
Likes: 26
From: Manchester - Political correctness is tyranny with manners.
um, why would you think it's valves when you put oil in the cylinder? That would be rings, not valves, unless you're saying that because it didn't come up much. Anyway, your best bet is not to guess (or have us guess) but to do (or have done) a leak down test. That will tell you if it's valves or rings or both.
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Verdad Gallardo
Banned Scam/Spammer
Joined: Jul 2006
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From: Simi Valley CA
Just didn't get what you meant. It would. I'd still do a leak down b4 tearing into it. Good Luck 
Team Owner
Joined: Mar 2001
Posts: 25,889
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From: Virginia Beach
CI 3-5-6-7-8 Veteran
Sometimes the valves don't fully seat w/ the car off... pull the valve cover, then hit the top of the valves on the #8 cylinder w/ a rubber mallet to force them to compress then seat in the head w/ the spring pressure. When I first changed my valve springs w/ compressed air I had a scenario where the valves weren't seating and air kept hissing out... I freaked out, but after a few raps w/ the rubber mallet all was fine.
Just a thought... free to check.
Just a thought... free to check.
Drifting
Joined: May 2003
Posts: 1,715
Likes: 1
From: cAshburn VA
Do you have a magnetic oil drain plug? Seen anything on there that might look like debris from broken rings?
#8 has a historical oiling problem, the result of many failed lifters, etc.
Pull that head. It's winter and its not that hard.
#8 has a historical oiling problem, the result of many failed lifters, etc.
Pull that head. It's winter and its not that hard.