zamboxl

iTrader: (1)

my car makes the exact same sound from the same side. I thought it was a lifter so i put new heads and new lifters, and the sound went away for like a few days then it came back so its not the lifter. The car actually sounded like that a long time ago i took the whole engine apart, it was a bad valve seat then i put it back together. The sound whent away for a few months but then it came back. Now i did the same thing i put new heads and new lifter and like i said sound whent away for a few days then it came back.

WICKED SS

iTrader: (36)

thats also how my 98 sounds (100k miles) and I got a new shortblock for it thinking it was a maybe bearing or something internal
still could be but would like to know what you find out.

1999T/A

iTrader: (4)

Yep it could be that too . It could be that you have just a few thousandths of a flat spot in one lobe and your lifter is fine causing excessive lash . I had a flat spot AND a bad lifter in mine , but the flat spot was due to the exploded lifter . The cam just ground away at the lifter . You wouldnt believe the amount of shrapnel I found in the pan . Hopefully you will be able to catch it before it gets as bad as mine did .

electricz28

I had similar noise on 98 found bad flywheel -good luck -I this has to suck

MW2 Performance

I had a noise that sounded similar on my girlfriends 72 nova, ended up being that the bolt on the flexplate goin into the converter was loose and was making a tapping sound, weird but just thought I'd shoot it out there.

LS1 Sounds

iTrader: (11)

The sound is definitely more of a knock when you hear it in person, the video makes it sound like a tap.

98A4LS1

iTrader: (1)

any updates?

The Knightrider

I just had the same sound that was around 2-3k rpm at first and only after it was warm. I thought it was the wrist pin also. I babied it around town for about a week then it started knocking all the time and the oil pressure started to drop 1-2 psi per day until it got to about 30 psi at idle. I then decided to tear down the motor and to my suprise found two spun rod bearings and a bad crank.

Does it make the sound all the time even when cold? If so it could be a lifter, but if it comes and goes then it is usually in the lower end.

bumpin_records

iTrader: (19)

rocker i think

The Knightrider

Any word on what the problem was??

10secondZ

iTrader: (24)

If that is a knock more than a tick, it deffinatly sounds like a rod bearing.If it is a ticking sound probably rocker or lifter collapsed..But generally lifter collapse isnt that pronounced.Inspect every rocker arm carefully and if they check out ok, then check for loose rockers at TDC compression on every cylinder for bad lifters.But if that fails..I would say rod bearing.Check your oil filter real good and magnet on the drain plug.

Carter

98A4LS1

iTrader: (1)

I hear two different sounds, valvetrain/lifter and lower like a rod bearing. Any updates?

CAT3

iTrader: (9)

Why not use a long metal pry bar or similar and isolate the problem, side to side, top to bottom by stethoscope? You can run it over each side of each cyl, at the top side of the cyl head to intake area and then again at the header flange area and if needed at the oil pan to block. It will definately tell you what cylinder is amuck. Try a cyl balance test as well. If its a wrist pin as you suspect, then the bal. test will be normal, but if its a lifter/valve the bal test should reveal it.

The Knightrider

I unscrewed the stick of my shop broom and put one end on the head and the other on my ear when I isolated mine.

I sounds pretty wild.

SLP CARS '98

iTrader: (1)

I noticed the car is an automatic so having a bent pushrod isn't very likely but my car sounded very similar to that when I found 4 bent pushrods in my car. NO I didn't miss a shift! I bought the car real cheap because the guy thought there was something seriously wrong with his car so I invested in a new set of pushrods for about $100. I put the new pushrods in and started the car up and it ran fine for about 2 minutes. After about 2 minutes I started to hear an engine noise. Turned out I didn't tighten one of the rocker arms completely. My guess is that the sound is coming from your valvetrain. I'm someone that hates to start throwing parts in a car and hopefully the problem eventually goes away but that will get very expensive very fast. With the amount of miles on the car I would start pulling apart the valvetrain and maybe you'll find something obviously wrong. If you don't see anything obviously wrong with both valve covers off and rocker arms and pushrods taken out you're going to have to go more in depth. Pull the heads off and take out all the lifters. See if any of the lifters have something obviously wrong with them. Maybe you'll get lucky and you'll find a bad lifter and just replace them. I would take the lifter retainers out and spin the motor over by hand and see if you can see any damage on the cam. It's good to get as much peoples opinion to see what they think could be the problem but I think it's time to start tearing things apart. While you're in there it might be a good time to put an aftermarket cam in there. Let us know what you find!

ricethis98

is your egr manifold on your headers tight and sealed?? seen it many times

Boostaholic

iTrader: (4)

What kind of oil pressure at idle? If it is a bearing your oil pressure will be low, if your still making 40psi at idle then thats good news.

technical

Bottom end....sounds like a rod bearing. One thing to remember with these engines is acoustics with an Al block are different than the iron. Can easily throw off your senses.

elite22xl

iTrader: (1)

i still wouldnt put the wrist pin idea out of your head, my mechanic hears a similar sound under my car, not nearly as bad, but he said he wants to keep a close watch on it.

LS1 Sounds

iTrader: (11)

The problem is definitely in the bottom end, I think the poor sound quality of the video is throwing some people off. We will figure it out when my buddy gets some money together to get his car back on the road and let you know what we find. Thanks everybody!