1987 Oldsmobile Delta 88 no compression

NATEMC

MEMBER
1987 OLDSMOBILE DELTA 88

Engine Mechanical problem
1987 Oldsmobile Delta 88 6 cyl Front Wheel Drive 120000 miles

I am working on a 87 olds delta 88 3.8 for my cousin, she drove it a short drive and shut it off for about 2 hours, when she went to start it, it just cranked, and would pop occasionaly. I checked it out and it has no compression but you can see the rocker arm moving in oil fill hole while cranking, I am pretty sure the timing chain/belt has jumped. I am wondering if this will usualy bend valves? And if there is any way to check without tearing the heads off. Thx for any help

Tuesday, January 13th, 2009 AT 4:43 PM

2 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Do a cylinder leakdown test in conjunction with a compression. Its not an interference engine

A cylinder that has poor compression but minimal leakage usually has a valvetrain problem such as a worn cam lobe, broken valve spring, collapsed lifter, bent push rod, etc.

If all the cylinders have low compression but show minimal leakage, the most likely cause is incorrect valve timing. The timing belt or chain may be off a notch or

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Tuesday, January 13th, 2009 AT 4:51 PM

MERLIN2021

MECHANIC
17,250 POSTS

Not on this engine, it's freewheeling, if the chain broke clen through, lifters wont go up and down. If it jumped a few teth will get your symtoms. No compression on all cylinders?

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Tuesday, January 13th, 2009 AT 4:52 PM