Eng Tapping Not Valves Or Lifters

[TRA RIV]

I HAVE 87.000 MI ON MY AURORA ,I WAS TOLD IT SOUND LIKE THE TIMING BELT TENSIONER OR A CRANKSHAFT BEARING THE TAP COME AND GO. I PURCHASE THE CAR IN AUG 05 THE CAR LOOKS NEW INSIDE AN D OUT AND RUNS GRATE (HELP) ENG DIAGNOSTIC SAID BAD LIFTER ON # 8 CYLINDER WHAT WILL IT COST TO FIX MY 1999 4.0 ENG

[bradan]

Originally Posted by TRA RIV

I HAVE 87.000 MI ON MY AURORA ,I WAS TOLD IT SOUND LIKE THE TIMING BELT TENSIONER OR A CRANKSHAFT BEARING THE TAP COME AND GO. I PURCHASE THE CAR IN AUG 05 THE CAR LOOKS NEW INSIDE AN D OUT AND RUNS GRATE (HELP)

What year? my 95 has similar noise+ a few others, possible answers?

[TRA RIV]

Originally Posted by bradan

What year? my 95 has similar noise+ a few others, possible answers?

1999 is year

[Indy8]

Engine has good 'ol fashioned timing chains, not belts. Not sure if there are even lifters on these or not. With some overhead cam designs the lobes directly lift the rocker arm and the other end of the arm contacts the valve stem, but these type need periodic adjustment. If the noise was main or rod bearing it would get worse real quick.

[ckpaas]

Are you using 91 octane or higher fuel? The high octane requirement is so a pre-detonation doesn't occur. The pinging could be just that (pre-detonation) which is the cylinder firing when the piston is on the up stroke.

[TRA RIV]

Originally Posted by Indy8

Engine has good 'ol fashioned timing chains, not belts. Not sure if there are even lifters on these or not. With some overhead cam designs the lobes directly lift the rocker arm and the other end of the arm contacts the valve stem, but these type need periodic adjustment. If the noise was main or rod bearing it would get worse real quick.

THANKS FOR THE INFO

[TRA RIV]

Originally Posted by ckpaas

Are you using 91 octane or higher fuel? The high octane requirement is so a pre-detonation doesn't occur. The pinging could be just that (pre-detonation) which is the cylinder firing when the piston is on the up stroke.

YES 91 AND HIGHER OCTANE AT TIMES THANKS FOR INFO

[bradan]

Originally Posted by Indy8

Engine has good 'ol fashioned timing chains, not belts. Not sure if there are even lifters on these or not. With some overhead cam designs the lobes directly lift the rocker arm and the other end of the arm contacts the valve stem, but these type need periodic adjustment. If the noise was main or rod bearing it would get worse real quick.

Would that apply to '95 w/ 100,000 m? If so, how do i go about that periodic adjustment?

[Indy8]

Hydraulic lifters 'pump up' with oil at start-up and operate in a zero lash state keeping in constant contact with the valve and rocker arm. Someone in this forum who has had the valve cover(s) off their engine would need to confirm that they are in fact hydraulic. Engines are now designed to be no maintenance so I really don't think they would be the flat tappet style. GM has used hydraulic since the 50's.

[TRA RIV]

Originally Posted by Indy8

Hydraulic lifters 'pump up' with oil at start-up and operate in a zero lash state keeping in constant contact with the valve and rocker arm. Someone in this forum who has had the valve cover(s) off their engine would need to confirm that they are in fact hydraulic. Engines are now designed to be no maintenance so I really don't think they would be the flat tappet style. GM has used hydraulic since the 50's.

help me if you had the vavle covers off, are there rocker arms or cams followers.