Tapping coming from under valve cover (not lifter tick)

[Aphix]

A couple days ago I was cruising home on the interstate when I began to hear a tapping, I pulled off at a gas station and began listening around. Since the tap was so prominent and clearly not just your average lifter tick, I trailered it home.

Once I got it home I used a stethoscope to listen around the head and determined that it had been coming from the front corner near the flange leading to your Oil Catch Can. The tap only seems to happen once I rev it to about 2k and then will increase and decrease relative to the rpms.

Anyways, I'm pretty certain it is a stuck lifter, so I just finished running a quart of ATF through the engine for about 45 minutes (being careful to rev it up to keep up oil pressure) and it hasnt changed the situation. Although my valvetrain sure looks pretty now!

Anyways, the stethoscope helped me to pinpoint the tap to that front left corner, and I need to either:

A: Unstick the lifter
B: Determine it isnt the lifter and diagnose the real problem

I have been doing some googling for a couple days and haven't found much on the process of doing this. I am going to check the timing just in case, I just wanted to get this thread up. Any help with the diagnosis would be awesome.

I considered loostening the camshaft caps and trying to get the rockers wiggled out and pulling the lifters in the front left corner (which are also the farthest from the cam pulleys), but I'm really concerned about the timing belt tensioner etc.

 

[Aphix]

I ended up using the vfaq guide which really made my life easier. Anyways, I replaced the front three lifters that I was pretty certain were the culprit of the issue, with three others. They are giving me lifter tick, but the louder tap that is consistent with lifter tick has not changed. Has anybody experienced anything like this?

 

[bastarddsm]

A spun rear ballancer shaft bearing makes that sound.

 

[ed1380]

I'm having a very similar noise. weird ticking/scraping sound by the front passenger side of the valve cover

 

[newTSIguy]

I'm actually having the same problem, I thought it was my lifters so I put in the revised ones and no change, its wierd though, it happens mostly on startup and quiets down if I get on it a little, but if I shut my car off for 5 min then start it up again it starts all over no mater the temp, is this similar to your problem?

 

[Aphix]

Right now mine will only begin tapping consistently once warmed up. And then it will only do it while the engine is over 2k rpms. It seems to have diminished but it isn't gone. I feel like it is a rocker not getting enough tension but I'm not for certain

 

[Aphix]

I replaced the lifters from the area I was getting the tap from but it hasn't fixed it. Maybe a rocker out of spec?

 

[lauj2gdsm]

sounds like C.W.

 

[Aphix]

If it was crankwalk wouldnt I be hearing the tap from the block? I'm getting this specifically from the front left of the head in a 5x5 inch area with my stethoscope.

If I put gloves on I can even feel it on the head.

 

[g4ebguy90]

crankwalk is just wear of the cranks bearings. The center bearing wears out, lets the crank have a little excessive play. Shouldn't make noise unless you can move it with your hand. But I highly doubt that is it.

 

[Calan]

All three of those posts ^ sound like it could be piston slap if you've ruled out the lifters, although it's usually worse when the engine is cold. But it will come and go at different RPM's, depending on the engine.

I considered loostening the camshaft caps and trying to get the rockers wiggled out and pulling the lifters in the front left corner (which are also the farthest from the cam pulleys), but I'm really concerned about the timing belt tensioner etc.

You can pry the rockers off and remove the lifters without loosening any cam caps.

 

[AG 305]

You can pry the rockers off and remove the lifters without loosening any cam caps.

so youre saying i can replace lifters without removing the cams at all?? cause thatll be the best thing ive heard in a long time!

 

[Calan]

so youre saying i can replace lifters without removing the cams at all?? cause thatll be the best thing ive heard in a long time!

Yep. Just takes a large flat blade screwdriver, a prybar, some patience, and a little experimentation until you learn where and how to pry on each one. A couple of them are a little tough to get back into place, but certainly doable. I've done it many times.

Mack's article explains it pretty well: http://www.dsmtuners.com/forums/articles-engine-fuel/265060-how-replace-lash-adjusters-lifters.html

 

[Aphix]

Yeah right after I posted this my buddy told me about the VFAQ guide. I've had lifters in and out of it a few times now. What are the odds of a rocker being out of spec and causing the tap to be coming from the cam lobe?

 

[AG 305]

Yep. Just takes a large flat blade screwdriver, a prybar, some patience, and a little experimentation until you learn where and how to pry on each one. A couple of them are a little tough to get back into place, but certainly doable. I've done it many times.

I believe Brian (snowborder714) has an article on here somewhere, but I can't find the link at the moment.

EDIT:

Mack's article explains it: http://www.dsmtuners.com/forums/articles-engine-fuel/265060-how-replace-lash-adjusters-lifters.html

thanks for the link. im sure tons of elbow gease is gonna be necessary

 

[Calan]

What are the odds of a rocker being out of spec and causing the tap to be coming from the cam lobe?

Anything's possible, but that doesn't sound too likely IMO... unless a lifter has collapsed. You may be getting a little valve float at higher RPMs if you are on old weak springs though.

thanks for the link. im sure tons of elbow gease is gonna be necessary

It's really not that hard at all once you get the hang of it.

 

[Aphix]

Yeah they were really easy thanks to the way they are designed. How would I go about diagnosing piston slap without pulling the head if at all possible

 

[Calan]

How would I go about diagnosing piston slap without pulling the head if at all possible

Pull the oil pan.

What oil do you run?

 

[pbwu1f]

This tool saved me tons of time. Schley Products, Inc , 99700 DOHC Hydraulic Valve Lifter Removal Tool - Mitsubishi / Chrysler.

 

[Aphix]

Pull the oil pan.

What oil do you run?

I just put 5w 30 in it for the coming colder months

 

[Calan]

I just put 5w 30 in it for the coming colder months

I'm guessing that is way too thin for Nebraska this time of year. Try at least a good 10w-40 in it and see if your noise goes away. It also wouldn't hurt to do a leak-down test just to make sure everything is in good shape.

There is an almost identical thread going on here: http://www.dsmtuners.com/forums/cyl...0-knocking-sound-any-ideas.html#post152706420 (I'm almost confusing myself with the replies.

BTW - Did you actually pull and clean/bleed/test all of the lifters?

 

[Aphix]

Haha of course. I search all over the forums for something relative to my problem and can't find it but then there is an identical active tread.

I had changed the oil after the problem began. Do you think the old oil could have lost viscosity and created that sort of issue? Its just weird because it seems to be one specific spot in the valvetrain.

 

[Aphix]

Also I did bleed all the lifters about 1k miles ago when I had the head hot tanked and resurfaced. And then I bled the lifters from the area the sound had been focused on. Now that I focus more on the block from the area the sound is coming from I am afraid it might be piston slap.. I can do some forum searching for more on this.

Thanks for the help calan

 

[Aphix]

Would fresh oil alter the effects of piston slap? When I changed the oil it seemed to improve the situation but didn't fix it. I just feel like it wouldn't unless it had that much of a difference to the oil rings. I'm about to do a compression test too.

 

[ed1380]

Oil wont affect piston slap. Piston slap will quiet down when the engine warms up