How to determine WHICH lifter is noisy? Replace roller lifter- existing cam?

[Jim 5]

To all the sharp minds. I have a '98 Chev Truck with the Vortec 350. After doing a ton of internet research, I have determined that the lifter noise I hear on start-up when the truck is cold is likely caused by lifter bleed down. The sound goes away after about 1 minute of driving. This appears to be a very common problem with the factory hydraulic roller lifters on the vortec 350's after about 120k miles. I have 170k miles. The roller lifters are generally known to be noisy.

I have 2 questions in this regard:

1. These roller lifters are pretty expensive. A whole set can run close to $500. I'd like to just figure out which one has gone bad, and replace that one. How do I figure this out?

2. With flat-tappet lifters my understanding is that if you replace the lifters, you've got to replace the cam, because new lifters and cams harden/temper themselves on initial run-in. An old cam would chew through new lifters and vice-versa. However, since my lifters are rollered...does this rule apply? I'd rather not buy a new cam-shaft as well.

I'd sure appreciate anyone's input on these points.

Jim

 

[eljefino]

If you take the valve cover off and wiggle your rocker arms you might feel play in one if the lifter has sagged. You'll have to turn the motor over 1/2 turn so the open valves close. If the rocker arms come off easily feel the lifters for "sponginess" or just a different feeling. You can even take lifters apart and soak their respective pieces in solvent then reassemble. Do it one at a time.

I've only done this on an OHC saturn with roller lifters, so my mental picture of "easy access" is vague for your engine.

If your lifters are good you might have piston slap. Have you tried any flushes like M1 5w30, ARX, MMO, etc? Does the noise change with different oils?

 

[1 FMF]

new cam requires new lifters, that's it. Use new lifters all you want with an old cam. However, if you misplace current lifters when doing valvetrain work then there's a chance that it will not ride properly on the cam and wear at a fast rate, wrecking itself and possibly the cam. So keep track of where each lifter belongs if you remove it. Whenever you replace a flat tappet with a new unused one, you have to do a 20 minute 2000 rpm break-in to establish proper wear in on the new lifter, the same process as breaking-in a new cam. You actually break-in the lifter, that's where the most wear occurs I believe not the camshaft lobe. Cranecams or compcams have tech articles describing this, if you haven't already read them.

Roller lifters require no break-in, and I don't believe it matters if you even swap them around. They don't establist a wear pattern and spin on the cam lobe like a flat tappet lifter. Replace them with used ones if you want, there are no restrictions- old cam new lifters, new cam old lifters, should all be ok.

sorry no clue how to find which ones are the noisy ones. You should hear my 02 LS1, they are all noisy on hot startup but quiet down after a few seconds. From what I've heard, GM lifters are typically noisy, and if they are at all a fast-bleed type then there's nothing you can do about startup noise. A new one will most likely do the same. That's the price you pay for the higher rpm and performance. Unless you have reason there's a real mechanical problem I would leave them alone.

 

[Jim 5]

Eljefino,

Just finished ARX clean and rinse. Also had one OCI with M1. The lifter noise was way louder with the M1. No improvement after the ARX.

As you have suggested, I'm considering adjusting the lash on the rocker arms, if this is possible on my engine. Access is decent. This was another recurring suggestion in my research. Comp cams provides a good method for doing this, and I've done it on several small block fords.

I may give that a try!

 

[kc8adu]

on my 5.7 roller motor i had a lifter clack only after letting it sit 5 minutes after a normal highway run.its like it needed a hot soak to act up.it would make a nasty clacking noise worse than any lifter noise i have ever heard.
only after restarting hot.
auto rx fixed it in the first run.took about 500 mi.
btw not sure it is related but on the drivers side one is oiling like crazy.it squirts oil while the others just get a normal flow down the rockers.

 

[Chris142]

Jim5. Have you been into the engine and atully seen the roller lifters?

I reciently replaced an intake gasket on a 99 Suburban 350 and noticed that it did not have roller lifters.

As for finding the noisey one. Remove the valve covers and start the engine. Use a .010 feeler guage and slide it between the valve stem and the rocker untill you find the one that gets quiet when the extra .010 is added.

 

[Jim 5]

Hmmm...

I just made an assumption Chris. I keep reading that the vortec 350's have rollers.

Good tip on the feeler guage. If a lifter has bled down...will .010 be enough to talke out the lash?

 

[Chris142]

quote:

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Originally posted by Jim 5:


Good tip on the feeler guage. If a lifter has bled down...will .010 be enough to talke out the lash?

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Its enuf to make an audible change.

 

[p-chem]

I've heard (from a friend and mechanic) that you can identify bad lifters by unplugging the sparkplug cap from the cylinder that you think is causing that noise. Without the pressure from combustion, the noise will go away. Without knowing which one, you might have to go through all to identify which one.

 

[kc8adu]

that may help isolate a rod or wristpin noise and also slap but i dont see how it will affect a lifter/valvetrain clearance issue

 

[Shannow]

But you'll always have one or more compressed lifters after an overnight sit.

Those on the top of the lobe will have the oil squshed out of them.

Take the covers off, and there will be one or more that have a "shock" that you can feel with your fingertips as the engine runs.

 

[motorguy222]

You may be able to check it this way.

After the truck has been idle overnight or all day,a couple of days may be better,take off the valve cover and see if you can turn or wobble any of the pushrods.

If you can,this may be the cause of the noise.

If you can turn/wobble any,you may be able to tighten the rocker arms to take up any slack.

I have taken up the slack on another GM product but I dont know if you can on this engine.

A repair book should help in this area.

 

[robbobster]

Have you tried listening through a length of rubber hose, like a stethoscope? Sometimes you can pinpoint the exact location of a sound using this method.

 

[jamesn]

a piece of rubber hose like a stethoscope will work in a pinch. but, for better results, get a mechanics stethoscope. i have had one for years and they are wonderful. harbor freight,6 bucks.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=41966
i had toyota trucks for years witht he 22r-22re engines. the valve lash went out all of the time. you just take the metal rod and put the end on the fulcrum or shaft of the rocker arm and you can hear it clear as a bell. no guesswork.

 

[Dave H]

I definitely second jamesn suggestion of a mechanic's stethoscope. It will easily allow you to pinpoint where a noise is coming from. You may be able to find one locally at AutoZone, Advance, Pep Boys for cheap.
Caution: They tend to amplify sound (duh), so some noises will be extremely loud. Also be cognizant of where the probe end is, as it is easy to hit a moving part (another duh). And hitting a moving part with the probe dramatically increases the problem of them amplifying sound levels. I'm speaking from personal experience on this one.

Dave

 

[Jim 5]

Great tips...all of them

I'm going to get a mechanic's stethescope for a start.

The last time I did this on a small block ford, you had to twist the pushrods when the cam was in a certain position, eg... for the intake valve...just after the exhaust valve for the same cylinder begins closing (or some similar procedure).

However, on those fords, the engine clattered all the time, not just when cold. Going through the procedure and adjusting the rockers did the trick.

I suppose I could do this procedure on the motor after it's been sitting for a few days...this should definitely show me which lifter is collapsing.

 

[robbobster]

quote:

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a piece of rubber hose like a stethoscope will work in a pinch. but, for better results, get a mechanics stethoscope. i have had one for years and they are wonderful. harbor freight,6 bucks.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=41966

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You mean they actually make this? I've been using a dopey jury-rigged length of those all this time.

For $6, I'm sold. Thanks for the info. These forums are great.

 

[Crashbox]

I'll throw in my vote for the mechanic's stethoscope also- have had one for years now. Indispensible when you need it. Some of the sounds you hear are pretty cool too...

Indeed, you must use caution while using the probe as Dave H mentioned.

 

[1sttruck]

"I'll throw in my vote for the mechanic's stethoscope also- have had one for years now. Indispensible when you need it."

Me too. I got mine from Sears, I think Danaher (?) makes a lot of their tools so NAPA might have a similar one. It has a simple but effective diaphragm and a nice length of small tubing to get into small places. I was able to check out each injector, even the ones under the throttle boy on the Taurus engine, by placing the probe on the body of each and checking for clicking while running. It has helped to find air leaks too.