1997 Nissan Sentra GA16DE Engine...Intereference or not?

Mikerizer

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#1
1997 Nissan Sentra, 225k miles, GA16DE engine

The end ring on the exhaust cam broke, and the upper timing chain jumped time. I replaced the exhaust cam with one from another motor, new chain/sprocket. Everything is in time. We have fire. I'm spraying bursts of starter fluid, so I don't think fuel is the issue. The distributor goes on only one way, so I'm positive it's positioned correctly.

The engine turns over, but won't start...not even hitting a lick.

Of course, I can't do a proper compression check, because I can't get the engine warm. However, a cold compression check shows 20 to 22 psi across all four cylinders...wet or dry. Specs call for 178 psi on a warm engine.

Is this an interference motor? I'm thinking maybe bent valves.
 

Mikerizer

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#2
a few hits from a search on the internet has me believing this is an interference engine, but I am seeing mixed results.

I'm eager to see what my trusted BAT friends think.
 

billr

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#3
22 psi compression on all cylinders, do you really doubt what has happened??? Put an air hose to the spark-plug holes, like in a leak-down test, you will hear or feel air coming out either the intake or exhaust and confirm the head has to come off. Hot or cold, compression won't ever be that low without bent rods, broken pistons, or bad valves...
 

Mikerizer

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#5
Yep, that confirmed it for me...1 cylinder had air coming through the tailpipe, 1 through the intake, and the other 2 through the crankcase; all with the valves closed.
 

billr

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#7
Well, you will probably have the head off and know for sure by the time you read this, but... leaking into the crankcase kind of hints that those pistons got broken. Oh, joy.
 

Mikerizer

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#8
Yeah, this one has already been rebuilt once...it belongs to my brother...I think he's going to sell it as-is, with full disclosure, or donate it to the kidney foundation, who will benefit via sale or scrap.