njedwardz

Hey all,

Take a look at this video:



Today my cammed 2013 started making this noise. I have made a point not to drive it any further yet. My diagnosis is a bad lifter, but I am a long way from being a mechanic so any expertise is appreciated.

Having the car trailered to the shop tomorrow, just wanted to have as much info as possible beforehand. thanks!

Brandon619

You definitely need to investigate, have you tried pulling the valve covers?

njedwardz

negative. car is at a friend's house for the night (did not want to drive it across town) and having it trailered to the shop tomorrow so we can see what the story is.

current thought from the mechanic is bad lifter, so new lifters and cam..probably gonna go ahead and mill the heads down a tad and go with a little more aggressive cam profile since we have to pull everything anyway....

rocker trunnions were upgraded with the BTR kit when we did the cam swap early this year, so I doubt that's the issue (although it certainly could be)

Brandon619

Good decision on not driving it. I would just add some thinner head gaskets to bump compression unless your rebuilding your heads? Keep us posted with your findings.

walleyejack

i would say not a bad lifter, been there, done that.

Dcasole

Does not sound like a bad lifter

But it does sound bad ....

Let us know what you find

don37

Does the noise continue without the serpentine belt(s) connected?

sabersaw30

Yeah i would deff take belt off first before ripping in motor.

njedwardz

That will be step one tomorrow. The noise doesn't seem to be coming from there, but it's hard to tell in general without a stethoscope. Obviously I would prefer the $100 fix to the $3000 one lol.

Would either a tensioner/pulley/belt issue or a bad lifter start making this noise spontaneously? It was not present at all before this afternoon; I was driving with very light throttle at maybe 20 mph when it started all of a sudden and sounded horrible. Pulled over within 1 min and took the videos then shut it down.

What would y'all say it sounds like? All I know is it sounds like metal-on-metal lol

User Omega

Sounds like it has bearing issues to me. As in you need a new engine. Start with the belt first but I think you are going to find it still does it. What is the oil pressure at idle? I would let some oil out of the pan and see what it looks like. 100% not a lifter.

njedwardz

Oil pressure is 30+ PSI at idle, 40+ while driving, 60+ WOT.

Would a bearing issue manifest to this degree with no previous indication, and during very mild driving? In the past 2 days, I haven't done any high-RPM, high-load, or high-G driving or anything else I would think would potentially spin a bearing (again, not a mechanic though). I never get on the throttle until trans temp is above 150 (oil is above 180 at this point). Last oil change was 3-4k miles ago. Probably 12-14k miles with this cam, 63k miles on the car total. Oil level is right where it should be.

If not a lifter issue, what other issues would sound like this and show up at such a (to me) random time? The more research I do, the more I think I may have just overreacted to a faulty tensioner or pulley, although I don't know whether that would just start out of nowhere either.

njedwardz

sorry about the double post.

Did a little analysis on the video, and it sounds to me like (by comparing to an online metronome) the squealing sound has peaks at around 325/min. Engine idle is set at around 650 RPM.

Correct me if I'm wrong, but the camshaft rotates at one half the rate of the crankshaft. Thus, a bad journal bearing would have peaks in sound ~650/min, and a cam/lifter issue would be ~325/min. A bad rod bearing...well idk where that would leave us. I believe the pulley ratio between the tensioner and crank pulley is also 1/2, so we would expect peaks ~1300/min, which may rule that out.

So my logic is that both a pulley or crank related issue is unlikely...While I could certainly have spun a cam bearing, it doesn't seem to be a common issue from my short google. Not that I found any videos with bad lifters that sound like my car, just trying to extrapolate.

User Omega

If you simply remove the drain plug for a moment and allow some oil to come out into a pan you can use a flashlight to look at it. If the oil comes out clean it is most likely not internal. It will look like glitter is in the oil if something internal is damaged.

If this is a lifter it has to have one of the roller bearings locked up or turned sideways. Usually a lifter that is failing will make a knocking noise long before the metal on metal screeching.

njedwardz

Okay, so I had a few minutes to do some tests this morning.

1. pulled the belt then started car. Let it run for a minute or two, no unusual noise or issues that I could tell. Tensioner pulley has a strange feeling to it but it doesn't wobble at all.

2. replaced belt, started and let run for a while. No noise at first, then very slight noise once warm.

3. drove down the street a few hundred yards. the same terrible squeaking sound began not long into this and continued until I shut the car off

4. restarted the car a minute or so later, and the squeaking was not present at any great volume.


My next step is going to be to warm up the engine then pull the belt and run it to see if the issue is still there. If it's not, we know it's something on the acc drive and it's just process of elimination (or just replace everything on the front of the motor lol). After that obviously check the condition of the oil just to make sure we don't have 2 issues.

Either way, my mechanic is coming to look at the car this afternoon, so we'll know for sure then.

schpenxel

Put stethoscope on power steering pump. That is what mine sounded like when it was failing (both times!). Sometimes it sounded horrible.. squealing/knocking and sometimes it wouldn't be all that loud.

It felt pretty rough when I spun it by hand, so you might could try that too

Stethoscope would confirm it though, hopefully that is all it is

If it IS the PS pump I'd add a filter to the return line if you can to at least try to filter any leftover junk out. There's not a decent place to add it pre-pump unfortunately. I think not doing that is what killed my first replacement

Dcasole

My money is on the tensioner , my C5 sounded and acted just like that when the bearing ran dry ....would not make any noise , then just a bit .... then really loud ....

schpenxel

That very well could be it too..

njedwardz

Well, this afternoon my mechanic took a close look at it with me and we believe it to indeed be a lifter issue.

At first, the issue wasn't present when we started it. Let it warm up and still nothing. Gave it light throttle up to 1800-2000 RPM and it sounded as though the whole place went to hell, misfiring and squealing and everything.

Noise coming from rear passenger side of motor, he initially suspected a rocker bearing failure. Removed valve covers and turned motor over without starting and confirmed that rocker bearings are fine.

Car was trailered to his shop tonight, will be disassembled tomorrow and we'll hopefully be able to see that the lifter is indeed the problem.

Why did we we suspect the lifter from the beginning? Well, I had forgotten this earlier, but the factory cam had a little nick in one of the lobes. At the time, we were confident that it was just poor material quality, and accepted the possibility that we had a lifter on the way out. Looks like that's manifested for us now lol.

So for now, assuming it IS the lifter, we'll be replacing all lifters with LS7 pieces and the cam as well (probably going to go a notch closer on the LSA just cause I want a little more lope than what I have now). May drop down a gasket size or mill the heads as mentioned previously to bump compression a little bit, but still undecided on that yet. Obviously this is all contingent on not finding any red flags during tear down.

Will post tomorrow evening with with update and hopefully some pics of whatever went to hell on me.

Dcasole

Wow that sucks ..... let us know what u find

GS057