Jump to content
HybridZ

noisy valve train, lifters, pitted cam


rossman

Recommended Posts

I recently purchased a '72 240z. The PO told me the engine and head were rebuilt approximately 10K miles ago. I love the car but I think valve train is excessively noisy. I tried adjusting the cam-to-rocker clearance twice, once cold, once hot but the noise is still there and didn't seem to change much in between. Actually it seemed more quiet after the cold setting. Here is a video of the car. Noisy eh? I read here and elsewhere that it could be worn lash pads. That will probably be my next fix after I try adjusting the valves one more time for good measure.

 

This morning I took the valve cover off and started inspecting everything. The cam looks kinda crappy as you can see in the pictures. These are cam lobes for cylinder 2 exhaust and 3 intake. I am wondering if this cam is trash. The car seems to run fine and there isn't a ridge at on the cam lobe.

 

If the next adjustment doesn't fix the problem should I start checking the wipe pattern on the rockers? Or am I wasting my time and should I get a new cam, rocker, lash pads, etc.?

00001a_thumb.jpg

00002a_thumb.jpg

Link to comment
Share on other sites

Or am I wasting my time and should I get a new cam, rocker, lash pads, etc.?

 

Oh dear! What does your gut tell you about this situation? You've already answered your own question.

 

Good luck.

Yep, looks like someone used an old cam and "polished" the rust off of it.

As for replacing everything, we would need to see the rocker arms and I doubt the lash pads are bad. Afew more pics would let us give you some better advice.

Link to comment
Share on other sites

Oh dear! What does your gut tell you about this situation? You've already answered your own question.

 

Good luck.

 

My gut tells me I got ripped off. The guy I bought it from knew nothing about the car. He just drove it for about a year then sold it to me.

Link to comment
Share on other sites

  • 5 weeks later...

I got it to quiet down by adjusting the valves cold and -.002 under the recommended clearance. If I remember correctly, that equates to .008 and .010. There is still a noticeable tick but it is much better. With the car running, I passed one end of a piece of PVC pipe over the valve train with my ear on the other to try to pinpoint the tick. As expected, the tick is pronounced near the scored lobes.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...