leakdown test results...uh oh!
Thread Starter
Instructor
Joined: Apr 2013
Posts: 116
Likes: 0
From: Liverpool New York
leakdown test results...uh oh!
Just did a leakdown on my 406. Ive noticed oil coming out of the filler cap and from around the pcv seats so I figured I had some blow by. all cylinders except for #7 tested adequate to good. cylinder 7 tested very poorly, and I can hear the air flowing into the valve cover when I remove the filler cap...it is blowing in the valve cover quite loudly. Could this be as simple as a rocker adjustment or am I looking at something more involved? Any thoughts on this will be appreciated.
Thanks!!!
Thanks!!!
Burning Brakes
Joined: Jul 2008
Posts: 914
Likes: 10
From: Brooklet Ga.
Pro
Joined: Apr 2013
Posts: 535
Likes: 8
From: London Ontario
This was a grade 9 auto shop lesson from way back..
Perform the compression test again on #7 dry. Then shoot some heavy oil in the hole and do it again. If the pressure goes up the problem is rings. If it doesn't its a valve or gasket problem.
Perform the compression test again on #7 dry. Then shoot some heavy oil in the hole and do it again. If the pressure goes up the problem is rings. If it doesn't its a valve or gasket problem.
Burning Brakes
Joined: Jul 2008
Posts: 914
Likes: 10
From: Brooklet Ga.
Well I was in grade 9 in 1966 where were YOU
Heel & Toe
Joined: Jun 2013
Posts: 17
Likes: 0
From: Caracas Miranda
I have to add if you have bad rings the compresed air and gas spray on your 7 and 8 conecting rods is going to ruin your bearins and probably the crank if you keep on driving like this, so tear it apart and change the rings asap
Melting Slicks
Joined: May 2006
Posts: 3,303
Likes: 14
From: Lynn MA
perhaps the next step....pull intake
pressurize cylinder, place lit match at intake port.....you may have your answer...you can also pull header, do same thing on exhaust
used this method to accurately find poor valve seats in my Grand National, I had a miss and we couldn't figure it out, my dad suggested this method and it was clear as day....be nice If you get away with a top end issue
pressurize cylinder, place lit match at intake port.....you may have your answer...you can also pull header, do same thing on exhaust
used this method to accurately find poor valve seats in my Grand National, I had a miss and we couldn't figure it out, my dad suggested this method and it was clear as day....be nice If you get away with a top end issue
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