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]

Originally Posted by Dynomite

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]

Originally Posted by 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.

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]

Originally Posted by 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 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]

Originally Posted by VetteMed

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]

Originally Posted by rhipsher

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]

Originally Posted by VetteMed

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]

Originally Posted by rhipsher

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

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