Take lots of pics and post them as you go. Especially of the valve train when pull the valve cover.

3 hours ago, mentalite said:

There is plenty of evidence that the previous owner was chasing driveability issues with the injection.  New AFM, new TPS, then $1000 at a mechanic to diagnose it back in 2008 and it still isn't right.  

That sounds like the evil coolant temp sensor.  Me and about half the 280 owners here have down the fix.  Mine spit a sputtered until 2,500 RPM then it would pull like normal.  Here's a link to the fix, cost me $5 from Radio Shack.  And a link to one the most helpful pages ever for Zs, more so 280s but now he has gotten into 240s and we're all waiting on that "Tech Tip" page.  Thanks @Blue and all your atlanticzcar.com buddies. 

Coolant sensor fix, http://atlanticz.ca/zclub/techtips/tempsensorpot/index.html

The Full Monty, http://atlanticz.ca/zclub/techtips/

Uh oh....that ain't good.

The source of the ticking was easy enough to find.  The intake valve on #6 (closest to firewall...is that #6?) is missing the little guide that the rocker sits in.  This has also caused the rocker to bash against the spring retainer.  The big question:  where the hell did it go?!

Now I'm stuck on what to do.  Repair it or move up the timeline on a rebuild?  Think I should try to replace that part and maybe the rocker to see what happens?  The valve is probably bent, too, I'd imagine.

12 minutes ago, siteunseen said:

That sounds like the evil coolant temp sensor.  Me and about half the 280 owners here have down the fix.  Mine spit a sputtered until 2,500 RPM then it would pull like normal.  Here's a link to the fix, cost me $5 from Radio Shack.  And a link to one the most helpful pages ever for Zs, more so 280s but now he has gotten into 240s and we're all waiting on that "Tech Tip" page.  Thanks @Blue and all your atlanticzcar.com buddies. 

Coolant sensor fix, http://atlanticz.ca/zclub/techtips/tempsensorpot/index.html

The Full Monty, http://atlanticz.ca/zclub/techtips/

Thanks!  I'll have to research and investigate.

Quick question:  Is it acceptable to turn the engine using the bolt on the end of the cam sprocket?  Crank bolt isn't very accessible.

11 minutes ago, mentalite said:

Quick question:  Is it acceptable to turn the engine using the bolt on the end of the cam sprocket?  Crank bolt isn't very accessible.

I've done it but it's easier to turn the cam.  It has some flats toward the rear for a big set of vise-grips.  Or put it in high gear and roll the car.  You always want to turn it clockwise from the front, keeps the timing chain tight.

I had a lash pad come off too.  It's easy to fix and somebody would probably give you one but I'll bet you find it.

 

Edited December 23, 20168 yr by siteunseen

8 minutes ago, mentalite said:

Quick question:  Is it acceptable to turn the engine using the bolt on the end of the cam sprocket?  Crank bolt isn't very accessible.

Yes, 19mm I believe.  Just make sure the trans is in neutral.

I figured it was going to be something drastic to cause all that noise. Now to figure out why. 

Does any of your service paperwork show any head work or engine work being done?

3 minutes ago, rcb280z said:

Does any of your service paperwork show any head work or engine work being done?

The PO attempted a valve adjustment himself.  That's all I'm aware of.

43 minutes ago, siteunseen said:

I've done it but it's easier to turn the cam.  It has some flats toward the rear for a big set of vise-grips.  Or put it in high gear and roll the car.  You always want to turn it clockwise from the front, keeps the timing chain tight.

I had a lash pad come off too.  It's easy to fix and somebody would probably give you one but I'll bet you find it.

 

Well, now.  That doesn't seem so bad after all!  That's a relief.  I'll poke around more thoroughly to look for it.

Here's another how to from JeffG, he showed me.  The PO probably didn't tighten the 17mm locknut on the stud.

If you don't find it, it is probably in the oil pan.  Could've bounced to the front hole where the timing chain is.  Here's some individual ones for $7.50.  I don't know the stock size but after looking at this I assume it's .150"?

http://www.thezstore.com/page/TZS/PROD/10-2041A

https://zcardepot.com/engine/cylinder-head?page=2

Edited December 23, 20168 yr by siteunseen