I have a 78 280z with 0 compression in cylinder 1 and limited in another.  I had car to.classic mechanic who suggested rebuild  of the engine. It starts but makes loud ping sound running.  He did not want to to do work because he was not familiar with Datsun.  Could not find replacement engine either. How do I find a mechanic to do work, and what is realistic cost? He said 5k which seemed high. Body is solid so fixing seems right idea, but I could use advice.

You need to tell us where you're located.

I live near Pottstown PA in the Philly suburbs

I wouldn't run that engine anymore. That will do more harm than good. Can you pull the engine and deliver it? I might be able to find time to build it. It's hard to estimate a cost until it is disassembled. My race engine was strong enough to finish 3rd but it needed a rebore, new pistons and the crank turned so you never know. A rebuild for your engine could easily cost $3000.

Chuck

 

Did your mechanic figure out the reason for the low compression? I'd want to know what's wrong before a rebuild. There's many reasons for low compression that can be repaired without a complete rebuild.  

Because of his lack of familiararity with the engine, he didn't remove the head.  He simply measured the compression.  Based on the clicking sound I shut it down right away and didn't run it longer.

I can't pull the engine myself and had it towed back to my place.  

It sounds just like this (not mine but the same)

 

What's your skill level? Are you comfortable pulling the valve cover off yourself?

And I'm not too far from you. Maybe half hour. Welcome aboard neighbor!

 I agree with the Captain. Pull the valve cover. It's easy. (Did your mechanic do that?) That tapping noise sounds like it is coming from the valve train. Look for a worn camshaft or loose pieces. (both are doubtful) If all looks OK, adjust the valves and take another compression test. BTW, although this may sound complicated if you've not done it before, it's all pretty basic and quite easy to understand and accomplish with a repair manual and a few hand tools. Adjusting the valve lash is part of a regular tune-up on Zs. It's a good thing to learn.

Could be a lash pad popped out?  I had one come off and have read where others have too. 

 

Edited May 15, 20177 yr by siteunseen

1 hour ago, siteunseen said:

Could be a lash pad popped out?  I had one come off and have read where others have too. 

 

 One of the loose pieces to look for.

If all else does not work, go to Z Car Source website, they sell rebuilt long blocks. I am in the process of installing a rebuilt L24 from Z Car in my '72. Will let you know what I think once I get further into my build...

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Thanks all, my skill level is novice. I can change filters and have done as much as rebuilt a mower engine and some carb work, but never his deep into the engine.  They didn't take the valve cover off, and I agree that the sound seems like it is right under the cover.  It wasn't started since the early 2000s and didn't have mechanical issues before it was mothballed.   I also have moisture coming from the tailpipe but it was idling well before the clicking started.

The bottom ends on these cars are super durable.  Worst case, it might need to have the head worked on, which can be done with the engine in the car.

Moisture from the exhaust is normal.  It's a byproduct of combustion.  

You'll need a Philips head screwdriver for the hose clamps, and a 10mm socket with an extension for the valve cover bolts.  If you've rebuilt a mower engine, you can easily get the cover off and determine the source of the problem.  Remove the hose, loosen the screws (leave them in the holes), and lift the cover straight up.  It's designed for easy, often, removal.  The gasket will probably tear when you remove the cover, so try to find a new one before you start.