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Strange Leak down Test Results

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Last fall bought  2003 ej253  that came from Copart car..The donor car was hit in front.. Engine damage is broken drivers side timing belt cover.Timing belt is still on with all timing marks in correct position. Just did a leak down test on engine.Getting 80 percent leak down on all four cylinders at exhaust ports. No  piston ring leaks and all four spark plugs have an even ware pattern with no oil fouling. I want to get correct diagnosis. without pulling the heads, because I'm selling the engine.

 

Doing complete rotation of engine from crank bolt, I'm getting  80 percent  leakage thru exhaust ports on all cylinders.So I will do valve lash adjustment on all intakes and exhaust and redo test..

Edited by steve56

Exhaust valves leaking?  Seems odd to be all four though.  

Check the valve clearance and adjust them. Exhaust valves tend to get tight over time.

They bend intake valves, not exhaust, if the timing fails. And if it were going to have a partially burned exhaust valve it certainly wouldn't be on all four cylinders.

 

Therefore I declare your testing method to be faulty. Those are implausible results.

 

GD

Testing using the wrong marks.

Arrows mark TDC. Arrows need to be at 12, 3, 6, and 9 when doing leak down test or the valves on the cyl you're testing will be open.

 

Timing hash marks are 45° off on cams and 90° off on the crank. Using timing marks for a leak down test, the Pistons will be at mid stroke and exhaust valves will be starting to open.

Edited by Fairtax4me

  • Author

What marks do I use for adjusting valve clearance.  Rally Suby! suggested my exhaust  might need to be adjusted.

  • Author

So are the arrow marks for tdc at 12 and 3 for the right head and at  6 and 9 for the left head?

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