Question about LT-1 small block
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8th Gear
Joined: Nov 2005
Posts: 8
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From: Corpus Christi TX
Question about LT-1 small block
I recently developed a loud pinging sound in the engine of my 96 LT-1 engine. I originally thought I had thrown a rod but noticed that I had no leaks and had not lost oil pressure. At idle the pinging is not noticeable but immediately upon throttle the pinging starts and appears to be coming from the right side of the motor. Dropped the oil pan and no chunks of metal were present, also went through the oil with a magnet and found no metal shavings. The motor has definetly lost power but again oil pressure is normal as well as all other guages. No codes were set off in diagnostics. If anyone has any ideas or possible conclusions to this problem I would be mighty grateful. Again it sounds like a rod but there are none of the normal signs that should be present with a thrown rod ??????
Large Impressive Member
Joined: Jul 2003
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
You didn't pull the valve covers before pulling the pan? Is there a miss or roughness? Under what conditions did the noise start?
Drifting
Joined: Sep 2003
Posts: 1,363
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From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
Is the pinging occuring all the time, or only when cold?
If not all the time, for about how long does it occur?
Might it be the AIR Injection Check Valves leaking?
On our 2000 Trans-Am with an LS1 engine, it had a terrible ping for the first 2-3 minutes when cold. It sounded like a really loose rocker or collapsed lifter.
It also threw a check-engine code for the AIR Injection passenger side Check Valve.
After replacing the passenger side check valve (it was rusted closed, no leak but no air was able to be pushed into the manifold) the noise lessened.
But, since the passenger one was bad, decided to replace the driver side one too. Good thing, as I found it was leaking in both directions. Afterwards, the pinging noise is almost gone.
I am thinking that next is to replace the plugs with Iradium's (GM TSB replaces platinium's with Iradium's) and expect the noise will go away completely.
If not all the time, for about how long does it occur?
Might it be the AIR Injection Check Valves leaking?
On our 2000 Trans-Am with an LS1 engine, it had a terrible ping for the first 2-3 minutes when cold. It sounded like a really loose rocker or collapsed lifter.
It also threw a check-engine code for the AIR Injection passenger side Check Valve.
After replacing the passenger side check valve (it was rusted closed, no leak but no air was able to be pushed into the manifold) the noise lessened.
But, since the passenger one was bad, decided to replace the driver side one too. Good thing, as I found it was leaking in both directions. Afterwards, the pinging noise is almost gone.
I am thinking that next is to replace the plugs with Iradium's (GM TSB replaces platinium's with Iradium's) and expect the noise will go away completely.
