Clickity-clacking (lifter/cam discussion)

[87geeinn]

A couple of days ago, I do a little ~20psi boost run on the interstate and hear a fairly loud clacking sound, consistent with RPMS, coming from what sounds like the #5 or #4 cylinder area and just behind the dash cluster. I eased it back home and popped the hood and can barely hear the clicking at idle and under no load. I take her back out for a quick spin and the noise immediately returns when the car is put under load, especially boost. I eased it back home and parked it. At this time, the car still drives fine, no knock, same oil psi as before, even under boost.

Now, I've always had a very slight ticking coming from that area for as long as I can remember. The passenger side has always been quiet as a mouse. Now that this symptom came up immediately, I'm beginning to suspect a collapsed or stuck lifter. I plan on popping the valve cover off and checking rocker travel, pushrods, cam sensor, crank sensor, and all of the usual suspected areas. If all that pans out, I may try some Marvel Mystery Oil and let it circulate for a bit and see if it doesn't quiet things down down some. Also, I may try spraying a little carb cleaner down the pushrods too. The only positive thing I can think of right now is that my cam is still intact since the problem surfaced all of a sudden and the car isn't acting funny at all. If none of that works, I reckon I'll have to pull the intake and take a gander at the lifters and cam.

Keep me in your prayers. I'll post back my findings in a few days. If anyone has any other suggestions, please chime in.

[kenmosher]

I hate to say it ... but ... might be headgasket pushed out to the exhaust side OR (if you're luckier) the infamous driver's side header crack. Both are something you can trace down with a garden hose and your ear.

[87geeinn]

might be headgasket pushed out to the exhaust side OR (if you're luckier) the infamous driver's side header crack.

I certainly considered that to be a possibility as well too Ken. I have to go dig around and find my compression tester tomorrow which is in storage 45 mins from here before I test for that. A little while back I ponied up for a set of stainless TA headers because of my stocker was so badly cracked (and didn't feel like continually repairing them). It certainly sounds almost like a really loud exhaust tick but has a more metallic ring to it, IMO. But we all know how elusive things can be sometimes.

[87geeinn]

Update:

Drained a quart of oil and poured in a quart of Marvel M.O. just for the hell of it. Pulled the driver's side valve cover off and ran the car for a while and started visually checking everything out. I also used a mechanic's stethescope to probe for any weird sounds. Everything up top looked and sounded okay: The rockers were all moving up and down their full amount of travel (best I could tell), pushrods were spinning, oil was coming out of the pushrods, no apparent cracks in the rockers, no cracks in the rocker shaft (heavy duty shaft w/braces), no cracked valve springs, cam sensor quiet, injectors sound normal, etc. The noise wasn't any louder with the valve cover off. However, the noise was much more pronounced when I stuck my head inside the engine bay closer to the windshield wiper reservoir area and revved the engine a bit. It sounds fine at idle but as soon as I crack the throttle a bit, the noise is there. If I get behind the wheel and brake boost it a bit, you can definitely hear it. BTW, car is still idling just fine, not showing any knock, and Scanmaster and AFR numbers are all still spot on. One other thing: I'm not sure how fast the pushrods are supposed to spin but I did notice that the #5 cylinder pushrods (both exhaust and intake) spun very slow, as in like one full revolution every 30 seconds or so. The #3 rods were a little faster and the #1 being the fastest. Don't know how big of a deal that is but they were spinning.

I eventually shut it down and tried manually pressing each rocker shaft down on the pushrod area to see if there was any play and there wasn't any.

It's starting to sound more and more like a headgasket issue. Oh well, I'll confirm this shortly. If that's the case, I'll be relieved that it's not something deeper internally. Furthermore, if it is a h.g., at least I don't have milkshaked oil or anything and it probably blew to the outside. Only speculating at this point.

[Keller]

Originally Posted by 87geeinn

Furthermore, if it is a h.g., at least I don't have milkshaked oil or anything and it probably blew to the outside. Only speculating at this point.

Only one sure way to find out...

[87geeinn]

Did a compression check this morning and that checked out okay. I even watched the rocker arms on the driver's side as I cranked the motor over with my remote starter and they "looked" okay. Replaced the valve cover and drove it around the block and the noise is still there, more so than before if I had to guess. It really sounds like something is banging into the rocker arm either on the #5 cylinder...or possibly #3 cylinder.

At this point, I'm suspecting a cam lobe(s) beginning to go flat unless y'all have some other ideas. I'm going to drain the oil and possibly pull the oil pan down and try to get a look at the cam from underneath. At least I can check for debris in the pan if it by chance hasn't gotten sucked up and circulated throught the motor already.

I have a gut feeling that tells me a cam change is in my future.

[kenmosher]

Might just put a dial indicator on the suspected rockers and see if the lift is gone? Might be simpler?

Might even be a collapsed or sticking lifter?

[87geeinn]

Drained oil, pulled pan, everything looked okay. I used my flywheel turner to spin the motor and I could see most of the lobes except for maybe the ones for cylinders #1 and #2 due to the crossmember being in the way. They all looked fine to me. Here's the thing: I have the TA stainless headers which are known to have fitment problems with the crossover pipe not lining up on the flanges. They use these grey circular gaskets between the slip fittings where the crossover meets the headers. Once I crawled under there to drop my oil pan, I noticed a piece of one of those gaskets protruding from between the joint. Once I unbolted the last v-band clamp off, the crossover pipe came crashing down. The little gaskets were fragile like potato chips and were in a gazillion pieces. On the driver's side header flange where the crossover pipe fitting is, I could see where there were two carbon tracks where exhaust was escaping. This also happens to be right below the #5 cylinder area (similar to the stock location). Note the pics. In one of them, there's a spot on the block that is clean of any oil residue and looks like it may have been from the exhaust gasses blowing out of such a small hole, effectively pressure washing the block. Who knows. In any event, you can definitely see the carbon tracks. Maybe this is whay I am hearing. FWIW, when I'm driving the car, it sounds like it's coming from right behind the dash cluster which would put that in just the right spot...especially if there's a high pressure exhaust leak pounding out right near, or on the firewall right there in that spot.

I have new gaskets on the way. I'll try them and see what becomes of that. Hey, it's a shot in the dark but I want to try it out before I start digging even more. If that's what I'm hearing, that's the clickiest exhaust leak I've ever heard. Ummm, yeah, I need to sleep. I will update in a few days.

[kenmosher]

Hope that's it! Heckuva lot simpler fix!

[IL KIM]

Good luck Austin. Sounds like you are narrowing in on the source.