NO COMPRESSION ON #2 CLYINDER

  • Tiny
  • Randall Moore
  • 1992 Jeep Cherokee
  • 200,000 miles

My 1992 Jeep Cherokee Laredo is running rough. All 6 cylinders are firing and getting fuel however, the #2 cylinder has no compression. You can place your finger over the spark plug hole and all cylinders feels the same however, when testing the compression with a gauge the #2 cylinder reads 0. You can put a small amount of oil into the cylinder and the compression rises to about 3 pounds. All the other cylinders read between 140 and 152. You can also remove the #2 spark plug wire with the engine running and it has no effect on the way the engine runs. All spark plugs looks new with just a light brown film on each plug which seems normal. The only thing I know to cause this is the valves. Do I need to rework the head or is there something else that could be causing this problem? Thanks Randall

Monday, March 12th, 2012 AT 2:11 AM

4 Answers

  • Tiny
  • fixitmr
  • Member

Yup, definately says valve probably exhaust.

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Monday, March 12th, 2012 AT 2:40 AM
  • Tiny
  • Randall Moore
  • Member

So if I get the head reworked I should be back on the road?

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Monday, March 12th, 2012 AT 3:50 AM
  • Tiny
  • fixitmr
  • Member

Yup!

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Tuesday, March 13th, 2012 AT 5:17 AM
  • Tiny
  • CJ MEDEVAC
  • Expert
  • 8,984 posts

SORTA PRELIMINARY

PULL YOUR VALVE COVER AND SEE IF THE VALVE IS IN THE "STUCK OPEN" POSITION (MOST LIKELY IT IS BURNT, SORTA LIKE A CRACK ON THE EDGE, ONLY SEEN WHEN THE HEAD IS REMOVED). BUT, I HAVE SEEN THE SMALL MIRACLE THINGS HAPPEN!

VALVE STUCK OPEN!--A SHOT OF PENETRATING OIL---A LITTLE TAPPING ON THE STEM---WAH-LAH!---IT MOVES AGAIN!

JUST LOOK FOR A FLOPPY ROCKER ARM (MAY HAVE TO ROTATE THE ENGINE TO REALLY SEE IT FLOPPING)

IF THINGS DON'T WORK OUT EZ, PULLING AND RE INSTALLING THE HEAD YOURSELF. COST OF GASKETS AND. AROUND HERE, THE ENTIRE MACHINING END AND A NEW VALVE IS NORMALLY LESS THAN $100

GOOD LUCK, KEEP US UPDATED

THE MEDIC

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Saturday, March 17th, 2012 AT 11:57 AM

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