johnny89345

iTrader: (1)

im still stuck I haven't used my car in weeks. I daily drive a tsp 408 with 247 heads, a ms4 cam. I hear a chirp in the motor and when the chirp is present the oil pressure drops significantly at idle to around 20psi as the needle bounces. I just took it for a quick ride and drove about 30 miles at a steady cruising speed with no noises and the oil pressure at idle around 40 psi with a very slight twitch of the op needle, on the way home I decided to step on it for a quick second in one gear just to see if the problem persists and sure enough once I let off the chirp sound arose and the op dropped. please help me diagnose this before I just give up on this car! its killing me that the motor only has literally 10k babied commuting miles on it ands already having these kind of issues. o yea I forgot to mention one of he valve springs and retainer broke a few weeks back, it snapped the outer spring in a few peices and a nice chunk off the titanium retainer I don't believe anything dropped down into the motor as I have no visible metal in the oil and all the pieced looked like pretty clean breaks. I don know how long I ran the motor with the broken spring one night the chirp was really loud so I popped the cover to find that.

johnny89345

iTrader: (1)

Im really hoping its just a bad lifter any advice would really be appreciated btw the motor has ls7 lifters in it

Burken01

iTrader: (88)

It will be hard to diagnose this problem over the Internet..

I would start by pulling the valve covers and check the valvetrain again.. You could bite the bullet and remove the heads and replace the lifters.. 1 might have turned slightly in the bore causing clearance issues allowing it to wobble a bit in the bore..

And what springs were you using that broke? Kinda random

S10xGN

iTrader: (11)

Remove the oil filter, cut it open, and tell us what you find...

johnny89345

iTrader: (1)

I never let you guus know what was going on so i fixed it. The issue was a failed lifter. The roller had about a half inch of play in it and was worn really unevenly. Also one of the skirts broke off.

74u

iTrader: (9)

Thanks for taking the time to post.

You catch it before any other damage took place? Was there any way to tell the lifter was the issue prior to teardown?

Deeohgie69

iTrader: (3)

^^^ yeah, was there any damage to your cam or anything? I ran across this the other week and was wondering. I wish everyone always came back like you and updated what the fix was.

johnny89345

iTrader: (1)

The lifter was absolutely the reason. Im going to try to post a video of it tonight to show you. The skirt on the lifter broke off luckily in two pieces that fell in the pan and if i tap the roller of the lifter on anything its a slight chirp noise but actually has up and down play like 3/4 of an inch. The roller also wore down enevenly. The cam on that lobe wore down a good bit so i replaced it with an eps cam. Other then all of that all is well..i pulled a few main caps to check the bearings while the pan was off and luckily all were in good shape. It really surprised me that one lifter could affect the oil pressure that much

74u

iTrader: (9)

No, I wasn't doubting the lifter failed and caused the issue. I was wondering if you were able to determine the lifter failed prior to taking it apart? If so, how? Good life skill for us pushrod motor guys to have

johnny89345

iTrader: (1)

To be completely honest nothing pointed towards the lifter. My reason for pulling the motor apart and initially thinking it was a lifter was solely based off a hunch. I spoke to numerous engine shops and they all told me i was crazy. One long island shop even told me the noise i was hearing was a wrist pin, that was literally the final straw and bullshit i was able to hear.

whatsa347

iTrader: (6)

Which lifters?

johnny89345

iTrader: (1)

Ls7 lifter failed now i have lunati 72532 linkbar lifters