JEB99TA

iTrader: (32)

I just turned 38,000 miles on my '99. Valvetrain noise just started about 2 months ago. It doesn't sound like a regular sewing machine ... more like the loud-*** kind that sews canvas tents together ... what should I do? What do you think my best option is from below?

1. Leakdown test?

2. Crank up more volume on the stereo and hope for the best?

3. Leave it alone and learn to enjoy that obnoxious friggin' noise?

4. Buy new AFR 205's and hope it fixes the problem?

mr2guru

iTrader: (16)

Pull your valve covers an look for obvious problems....ie loose rockers etc....

JEB99TA

iTrader: (32)

This may sound crazy, but, waaaaaay back in the country many years ago ... the general rule was to torque the rockers down firm-tight and back them off I believe it was like a 1/4 turn or something like that. Is this just old school country that worked on older cars, or, is there a general rule with newer LS1's ?

soundengineer

iTrader: (16)

actually the old school was to take out lash and then to turn an extra 1/4 - 1/2 turn.....
but this is new school....

torque the stock rockers to 22 ft/lbs... turn the engine over a few times...recheck them all....

all aftermarket rockers...follow what the maker says to do....many different types have many different instructions from one another

Technoman64

iTrader: (6)

I just installed Crane Adjustable 1.7 roller tip rockers tonight. Seems to have helped the noise some. Just ran it enough to warm it up though. The instructions called for zero lash, then tighten 1/4 turn every 15 minutes for a total of 2 full turns. Then tighten the locking set screws. I will post after running it more tommorow. I think the TR224 cams are somewhat noisy anyways due the ramp rates.
I guess I could use this as a good excuse to go with better heads, bigger cam, and new lifters

JEB99TA

iTrader: (32)

Will it mattter that I have hardened TR 7.400" rods and 918 comp springs. Would 22 ft/lbs be the correct torque?

1BADAIR

iTrader: (1)

Yes. Any nonadjustable rocker should be torqued to 22. If the noise just started,I would take a close look at the rocker arms. You may have one starting to come apart. My Tr224 had alot of valvetrain noise.

luv2spd

iTrader: (1)

As long as you have stock rockers yes.

Steve Bryant

iTrader: (1)

The two things that I would recommend for now would be to replace the push rods with some stiffer units and maybe replace the lifters. You should know tomorrow whether pre-loading the valve lifters with the two revolutions of the adjustment nuts will quieten things down or not. If things get quieter (no or very little clicking sounds) then your lifters are probably OK. However, regardless of whether the valve train gets quieter or not, I'd definitely replace the pushrods. There are many good pushrods on the market for the LS1. This is really a weak spot as you push the engine above 6,200 RPM's and with the ramp rate and lift of your cam you should definitely do this.

Another thing to look at is do the pushrods appear to be oiling the rocker arms. Each time the lifter rides up the cam lobe and the opposing valve spring pressure causes the lifter to compress a little, it squirts a little oil up through the pushrod. The oil then drizzles down the rocker arm oiling the roller bearings and now the roller tip and the contact point between the tip and the end of the valve stem. If a lifter or pushrod is plugged-up and not oiling the rocker arm friction points, then that can cause a sewing machine sound. Take a close look at your factory rockers for abnormal wear patterns at the pushrod end, the tip and the roller bearings. Does everything look like it's been well oiled and no real evidence of wear?

Sorry for such a long post. You probably know most if not all of this stuff. However, I thought that I would kind of give a rundown on what could cause the noise.

Best of luck,

Steve

Technoman64

iTrader: (6)

What cams are available that are similar to the TR224 but are quieter (less valve train noise). TR224 is the only cam I have tried. I have 918 springs and the hardened pushrods with guide plates(came with the Crane roller rockers).

luv2spd

iTrader: (1)

Maybe the tsp 224. They have both the 224 and a 224R, but the regular 224 will have slower ramps and less noise.

JEB99TA

iTrader: (32)

Steve, you were probably still typing your reply while I was posting that I have hardened pushrods, even though I will still look at them closely. Man, if I've warped one of those, I guess I should be proud ...LOL!!!! Anything is possible, I guess.

Guess I know how I'll spend my Saturday morning. I thought at first the oil pump was defective, but, I'd probably know that by now ... pressure is good. Thanks for the information folks.

Steve Bryant

iTrader: (1)

I really doubt that you've bent a pushrod since they are hardened. An easy way to check for straightness is to roll them under the palm of your hand on a flat surface like a piece of plate glass. If they roll smoothly, they're straight. If they hop up and down, they're bent. Now a bent rod or a collapsed lifter will increase your valve lash and make a ticking or clicking sound. A loud sewing machine sound that is growing louder is typically caused by something reciprocating back and forth like a rocker arm or a valve in the guide or something like that. However, the higher the lift and the stronger the springs, etc., the nosier (sewing machine sounds) the valve train will be even if everything is normal.

Steve

BTW, I see that you have Tennessee/Central Florida in your signature. I'm originally from Cleveland, TN.

JEB99TA

iTrader: (32)

Thanks for your input Steve. I'm from Harriman ... just down the road from Cleveland. Beautiful place, but, a lot of rif-raf. I'll pull the covers and post back what I find tomorrow. If I have a bad valve seat or two ... are thay pretty easy to replace if I buy a valve spring tool.

gwj

I'm over 122K on stock internals. Starting to get kind of noisy on the top end-over and above the noise thats been there since new. My guess (at least in my case) is lifter or rockers. Don't have any experience w/hardened pr's in LS1's but of course a bent one in any engine will cause racket. Based on past experience, even a visual inspection of rockers won't always tell you what you want to know if you don't know what to look for. And lifters-well if I went so far as to look at them I would just replace them, if budget allows. Springs get weak eventually.
Luck,
Gerald

Steve Bryant

iTrader: (1)

JEB99TA,
The cylinder heads have hardened valve seats inserted into the combustion chambers and the valves seat against them. The valve seats are where the three (or 5 or 1) angle valve job is machined when you get a valve job. If you had a bad valve seat, you might have poor compression (and be low on power), but it wouldn't be causing the sewing machine noise.

Steve

JEB99TA

iTrader: (32)

Thanks Steve. I want to get heads and just replace the whole valvetrain, however, I have read some posts here and several folks have done that ... and still have the same problems/noise.

I will try to pinpoint the problem if there's any way to do that ... thinking next step being a leakdown test. It doesn't feel like it's lost any power, though. I'm replacing the stock pulley and belts as soon as the ASP I ordered ships. Hopefully, maybe this will help. It seems the noise may be coming from the harmonic balancer hub ... have no idea what could go bad with the hub, but, it could be down deeper in the engine. When I rev the engine at fairly high rpm's, it's developing a sort of whine almost like a supercharger or something ... along with the vavletrain noise that really isn't valvetrain noise ... what do you think?

Steve Bryant

iTrader: (1)

One thing you might try is to isolate the source of the noise if you can by using about three feet of hose with one end held up to your ear and move the other end around the engine like it is a microphone. Also, you could pick up a mechanic's stethoscope and probe around on the engine. Another thing you could do is take it in to a couple of independent shops with LS1 experience and ask them to diagnose it and give you an estimate for repair. Whether you have them repair it or not is your shot to call. However, this might give you some ideas from someone who's experienced and been down the road before.

Steve

Cal

iTrader: (1)

When I ran a TR224 it was very quiet. I think it's a matter of getting push rods the right length so there is the right amout of preload on the lifters.