Risk of ignoring lifter noise?

[VetteMed]

As my ZR-1 nears 195k miles, I've noticed that the noise which I and a few other forum members think might be lifter noise, seems to be worsening slowly. The motor runs great, but at idle, there's a noticeable tapping noise coming from what sounds like under the plenum. If this IS one or more lifters that is collapsed or otherwise defective, is this a big risk for the affected cam(s) involved? I am having a hard time justifying pulling the motor out, given that it seems silly to swap lifters, and then put such a high mileage motor back in the car.

I have absolutely no budget for any thoughts of a rebuild, or a used LT5 from a part-out. If I wipe a cam lobe, or if the engine otherwise pukes, the car will be sitting for a LONG time.

I'm not really sure what I'm looking to hear -- I know I'm probably gambling by continuing to drive the car a few hundred miles per week.

Is it worthwhile to try a different (read: thicker) oil? I've been running Mobil1 10W-30 High Mileage.

Recently changed plugs, have good even clean burn in all cylinders, FWIW. 20mpg in mixed driving.

Thanks for any input!

[VetteMed]

I say pull the cam covers and take a closer look

What will I be looking for? I don't think I can visually diagnose a bad lifter?

[Hib Halverson]

With 195,000 miles on the engine, it wouldn't surprise me if some components in the valve train are reaching their design-life limit.

If you don't have the budget for repair of a major component maybe you'd better investigate further then make the "non-op" decision. Better to put the car on blocks for a while than wipe-out a camshaft.

If it was a lifter problem, you'd hear it in the cam covers. If you're hearing it coming from beneath the intake manifold, the problem might be other than valve train.

Lisle makes an excellent automotive stethoscope. I've pinpointed many an engine noise with one of those.

[VetteMed]

With 195,000 miles on the engine, it wouldn't surprise me if some components in the valve train are reaching their design-life limit.

If you don't have the budget for repair of a major component maybe you'd better investigate further then make the "non-op" decision. Better to put the car on blocks for a while than wipe-out a camshaft.

If it was a lifter problem, you'd hear it in the cam covers. If you're hearing it coming from beneath the intake manifold, the problem might be other than valve train.

Lisle makes an excellent automotive stethoscope. I've pinpointed many an engine noise with one of those.

Thanks, Hib. I'll try to pick up one of those mechanic's stethoscopes tomorrow. I guess I shouldn't use the real stethoscope that I use for work ;)

I know I'd hate to wipe out a cam, I guess I know deep-down that I need to diagnose the issue and not just drive it into the ground. I've been so happy to put some miles on the car lately after working on it for so long, I guess the devil on my shoulder kept pushing me to keep driving.

Not sure if this helps or makes any sense -- but when the motor is cold, especially, the noise comes in "waves", almost like there's some harmonics at play, it will go from quiet, to a fairly rapid crescendo, with tap-tap-tap (probably 4-5 per second), then drop back to quiet for another few seconds.

[rhipsher]

Let me just say 194k? That is freaken awesome. My opinion is that your probably long overdue for new lifters. Id pull the cam cover on the side you think its on and just replace that one lifter for now and you'll be good to go. Replacing one lifter shouldn't break the bank. When you get the cam cover off just fire the car up and and you'll find it quick. Just don't rev the engine. Lol! A face full of hot oil will make you do the rumple stilskin dance.
On all the other cars I've ever done a valve adjustment on or looked for a bad lifter I would just buy a cheap set of valve covers and just cut a slot in the top of them so I could see what's going on in there without engine oil going all over the place. You'll probably have to fasion something to deflect the oil from going all over the place.

[VetteMed]

Let me just say 194k? That is freaken awesome. My opinion is that your probably long overdue for new lifters. Id pull the cam cover on the side you think its on and just replace that one lifter for now and you'll be good to go. Replacing one lifter shouldn't break the bank. When you get the cam cover off just fire the car up and and you'll find it quick. Just don't rev the engine. Lol! A face full of hot oil will make you do the rumple stilskin dance.
On all the other cars I've ever done a valve adjustment on or looked for a bad lifter I would just buy a cheap set of valve covers and just cut a slot in the top of them so I could see what's going on in there without engine oil going all over the place. You'll probably have to tasking something to deflect the oil from going all over the place.

Only problem is that to change a lifter, requires removing the cam(s), which then requires timing the cams, which from what I've read, typically should be done with the motor out of the car.

On an OHV motor, yeah, it's a no brainer to change the lifters...

[rhipsher]

Only problem is that to change a lifter, requires removing the cam(s), which then requires timing the cams, which from what I've read, typically should be done with the motor out of the car.

On an OHV motor, yeah, it's a no brainer to change the lifters... In that case I wouldn't drive the car anymore until you can afford to do something about it. Since it sounds like its your daily driver id go buy a POS to drive back and fourth and park the Z.

[VetteMed]

In that case I wouldn't drive the car anymore until you can afford to do something about it. Since it sounds like itsnot your daily driver id go buy a POS to drive back and fourth and park the Z.

Got my Duramax powered truck for my DD if needed -- though the Z was my DD for the last couple of months, better mileage, more fun. Ah well.

[rhipsher]

Got my Duramax powered truck for my DD if needed -- though the Z was my DD for the last couple of months, better mileage, moe fun. Ah well. There you go. Nothing like a $55k pickup truck to dd in.

[VetteMed]

There you go. Nothing like a $55k pickup truck to dd in.

yeah, about a fifth of that price:o... 2002 2500HD.

[rhipsher]

My buddy bought one of those Ford 1super ton King Ranch super duty pickups Brand new. $55k 6 months later he couldn't afford the payments anymore. I knew that was coming. Lol!

[VetteMed]

My buddy bought one of those Ford 1super ton King Ranch super duty pickups Brand new. $55k 6pickup months later he couldn't afford the payments anymore. I knew that was coming. Lol!

Yep, that's a lotta green for the new trucks. Too rich for my blood...

[GOLDCYLON]

You have no secondaries right? blades removed etc? Mine did this before the blades broke apart and hit the pistons


Another option according to Lee since your on a budget on a hi miler anyway

http://www.zr1.net/forum/showthread.php?t=16532

[VetteMed]

You have no secondaries right? blades removed etc? Mine did this before the blades broke apart and hit the pistons


Another option according to Lee snce your on a budget on a hi miler anyway

http://www.zr1.net/forum/showthread.php?t=16532

Correct, no secondaries. I thought at first that this noise was coming from one of the accessories, but I don't think that's the case now.

Thanks for the reminder on that option for lifters- however, I'd suspect that a lifter that is collapsed or otherwise damaged in a way other than wear on the surface that contacts the cam lobes, it's better to just replace it.

[VetteMed]

Hmm, looks like they offer true rebuilding services, not just refinishing the surface. Good to know.

[GOLDCYLON]

Correct, no secondaries. I thought at first that this noise was coming from one of the accessories, but I don't think that's the case now.

Thanks for the reminder on that option for lifters- however, I'd suspect that a lifter that is collapsed or otherwise damaged in a way other than wear on the surface that contacts the cam lobes, it's better to just replace it.


Concur I would just buy Thier cores already done

Any pieces missing out of the balancer? this will cause a knocking as well is the motor shaking as well? Or just noise under the plenum or cam covers. Can you post up a video ?

[GOLDCYLON]

Hmm, looks like they offer true rebuilding services, not just refinishing the surface. Good to know.


Correct on the cheap as well.

[VetteMed]

Concur I would just buy Thier cores already done

Any pieces missing out of the balancer? this will cause a knocking as well is the motor shaking as well?

I haven't noticed any pieces missing from the balancer - I will inspect tomorrow to be sure. The motor is pretty smooth overall, but at times does have a little shake to it.

[sammy]

just a thought ,but do a fuel pressure test and see if it holds. i know you put in new ones but sometimes they do go bad or leak .

[Pete]

I have a question did the noise start after you installed new injectors.
Another question did you buy the injectors from FIC?
You say it varies with temps?

I like to start from cheap to expensive.

I would check spark plugs new or not,i had a brand new spark plug drove me nuts trying to find the noise.
Check coils,wires.

Then move to lifters.
If you know which bank the lifter noise is on i would change all the lifters with new lifters on that bank price is not so bad $15-$20 each X 16 lifters,what i would do in your position is pin the cams like the FSM or post when you get that far and we'll help.
Not such a bad job just go slow and take your time,just make sure it's lifters.

Pete

[VetteMed]

I have a question did the noise start after you installed new injectors.
Another question did you buy the injectors from FIC?
You say it varies with temps?

I like to start from cheap to expensive.

I would check spark plugs new or not,i had a brand new spark plug drove me nuts trying to find the noise.
Check coils,wires.

Then move to lifters.
If you know which bank the lifter noise is on i would change all the lifters with new lifters on that bank price is not so bad $15-$20 each X 16 lifters,what i would do in your position is pin the cams like the FSM or post when you get that far and we'll help.
Not such a bad job just go slow and take your time,just make sure it's lifters.

Pete

Pete, thanks for the suggestions. Initially the problem seemed worse when cold; now I'm not so sure. Seems pretty consistent now.

I just put new NGK Iridiums in last week to see if there was any improvement. Plug wires are about 2 years old ACDelco.. Same for coils.


I'll pull the plenum later to check everything.

Injectors are FIC, about a year old now. Something that has bothered me, is how quickly the motor fires after sitting for several hours or days. Everyone says the LT5 needs to crank a bit before actually firing -- which mine does, when warm. Cold, however, it lights off on the first crank of the starter, so I've been wondering if an injector or two are leaking down.

Thanks
Andrew

[VetteMed]

Pulled the plenum;

All injectors ohm out to about 14.4-14.6.
Pulled fuel rails, set up rails and injectors over cardboard.

With Key on, engine off, fuel pressure is at about 44 psi, no drips from any injectors.

[VetteMed]

Plug wires all ohm out to about 4 to 6Kohms, depending on length (longer = proportionately higher resistance).

[VetteMed]

fuel pressure holding well at over 40psi 10-15 minutes after pumps disengage.

[VetteMed]

Ignition coils:

Primary: 0.5-0.6 ohms for all 4 coils
Secondary: 5.1-5.2K ohms for all 4 coils.

[VetteMed]

No smoking gun here, in the ignition or fuel systems, obviously... so I guess it's on to pulling the cam covers.

[Pete]

How is your oil pressure.

One more suggestion.
Is there any members close to you that you can swap out fuel rail/injectors.

Pete

[VetteMed]

Oil pressure, as indicated on the dash gauge, is 60+psi cold, and 30-40psi hot.

Nobody particularly close, unfortunately... there's Belsy about an hour and a half away but his motor is assembled and running; I'd hate to have someone take stuff apart for my troubleshooting.

Before I pull the cam covers, a thought... - I removed the serpentine belt, and jiggled the pulleys of the various components. the power steering pump has a little bit of a clackety-type looseness to it. I have a low mile used OEM pump on the shelf (I think I bought it from you, Pete), and it seems to not make the same sound when the shaft is jiggled.

Possibly the source of the noise??

[sammy]

could be , might be worth changing to see . what kinda bothers me is the shaking you said the motor had to it . just food for thought .i had 1 pole go out on one of my coils . the car would run but had a stumble to it low rpms and when i got up to around 3,000 would smooth out . might ask jerry of jerrys gaskets how to ck to see if you have 1 pole gone bad . he told me how but i cant remember what he said .

[VetteMed]

OK, so the noise is NOT the power steering pump. I got everything back together, left the serpentine belt off, and started the motor. The noise is still present. It almost sounds to me like the noise that the tensioner makes upon cold startup, but it's persistent in a roughly sinusoidal fashion. Few seconds quiet, then gradual increase, peak, then decrease to silence again. I guess I'll pull the cam cover on the driver's side and take a look around.

[VetteMed]

Got the driver's side cam cover pulled (the noise was most prominent in this area). I really don't think anything "looks" any different from about 7k miles ago, which was the last time the cam covers were off, prior this noise developing.

There is some scoring on the bearing surfaces of the cam cover, but I don't know how much of that is normal wear.

Is there any way to determine which lifter(s) are bad, if any? I notice that when the cams are positioned such that the valves are closed, the lifters are able to spin / rotate, is this normal?

The wear strip on the LH chain guide is broken, but it does not appear any worse than 7k miles ago.

The edges of some of the timing chain links appear "polished", but I figure that's normal wear.


SO, where do I go from here?

Thanks,
Andrew

[VetteMed]

I suppose there's no sense in prolonging the inevitable here... I am going to plan to pull the motor out. I can now see that my diagnostic options are limited without actually holding any (defective) components in my hands. I guess this officially ends the "how far will my motor go without internal problems" question. The answer: just shy of 195K miles.

[Pete]

Got the driver's side cam cover pulled (the noise was most prominent in this area). I really don't think anything "looks" any different from about 7k miles ago, which was the last time the cam covers were off, prior this noise developing.

There is some scoring on the bearing surfaces of the cam cover, but I don't know how much of that is normal wear.

Is there any way to determine which lifter(s) are bad, if any? I notice that when the cams are positioned such that the valves are closed, the lifters are able to spin / rotate, is this normal?

The wear strip on the LH chain guide is broken, but it does not appear any worse than 7k miles ago.

The edges of some of the timing chain links appear "polished", but I figure that's normal wear.


SO, where do I go from here?

Thanks,
Andrew

Yes,on the lifter rotate

Yes,on the polished chain

If there was work done to the motor recently and before you yank the motor,i would look into the chain tensioner,tensioner is like a lifter.

Pete

[VetteMed]

Would the tensioner potentially cause the on-and-off oscillating type noise that I described?

Is there any way to diagnose a bad tensioner once it's removed?

[Pete]

Would the tensioner potentially cause the on-and-off oscillating type noise that I described?

Is there any way to diagnose a bad tensioner once it's removed?

Once you take it out it should release all the way out and should be able to take it apart into two pieces if not then it's stuck and no good.

Pete

[VetteMed]

Once you take it out it should release all the way out and should be able to take it apart into two pieces if not then it's stuck and no good.

Pete

OK, thanks Pete. I removed the LH tensioner earlier this evening, and it does in fact release and separate into two pieces. there's some scuffing along the surface where the tensioner contacts the guide, but it appears normal otherwise.

I am going to pull the RH tensioner tomorrow.

Is there a third tensioner for the main chain?

[Pete]

There is a third one but that one is basicly fixed.
Just make sure you reload the tensioners the right way before reinstalling them.

Pete