'78 280Z making ticking noise when engine warms up

[robftw]

I put seafoam in my crank case and ran it for 500 miles, my car used to tick like yours.

After that + adjusting the valves the problem went away.

[dankfrye@charter.net]

Thanks! I'll try that.

[cozye]

I put seafoam in my crank case and ran it for 500 miles, my car used to tick like yours.

After that + adjusting the valves the problem went away.

Did it stop ticking when you removed the plug wire to #6 ? I think that's the key here.

[dankfrye@charter.net]

Yes. It stopped ticking when I removed the plug wire to #6. When I swapped #5 and #6 plug wires, though, it started ticking again. I pretty much ruled out the plug wires, plugs and injectors by swapping them out. I also have brand new NKG plugs and plug wires.

[dankfrye@charter.net]

Did the Sea Foam treatment through the brake booster hose. Besides smoking up my garage and half the neighborhood, I did find an exhaust leak at the bottom of #6 exhaust bolt on the manifold. I tightened it up along with all the others and readjusted my valves the right way. The car seems to run quieter and stronger. I still have a light tick when engine is warmed up but it's not near as bad. My valves were all tight because the guy that showed me how to do a valve adjustment said to put the feeler gage under the tappets on the drivers side instead of directly under the cam lobes. This apparantly makes a pretty big difference.

Thanks for all you guys help!

[mrorange]

So glad I found this thread. I've been having a similar problem (ticking after warmup) with my '78 280. I've had suspicions about my exhaust, and now when I get back to where the car is this summer, I'll know what to look for! What a helpful thread and awesome example of the community here. Registered just to say that

[FastWoman]

Welcome, Orange, from another '78 owner! :-)

[cozye]

Did the Sea Foam treatment through the brake booster hose. Besides smoking up my garage and half the neighborhood, I did find an exhaust leak at the bottom of #6 exhaust bolt on the manifold. I tightened it up along with all the others and readjusted my valves the right way. The car seems to run quieter and stronger. I still have a light tick when engine is warmed up but it's not near as bad. My valves were all tight because the guy that showed me how to do a valve adjustment said to put the feeler gage under the tappets on the drivers side instead of directly under the cam lobes. This apparantly makes a pretty big difference.

Thanks for all you guys help!

Is the bolt stripped? I'm not sure how it would have loosened up enough to leak if you had just replaced the gasket. If its leaking at all it will only continue to get worse as the host exhaust gas burns what's left of the gasket out. I'm afraid you will still have to pull it all off, install a new gasket, and install helicoils in any stud that has weak threads. While its off, check the manifold for cracks and for warpage on the mating surface

[FastWoman]

Yeah, it might be warped or corroded. That old '77 Chrysler Marine 318 I have in my boat is giving me this headache. Unfortunately the problem is on the mating surface of the head, not the manifold, or else I'd just have it milled.

[dankfrye@charter.net]

The exhaust manifold might have a slight warp but now it is very small and the noise is barely audible. I never remove the exhaust manifold because the 3 bolts on the flange were very rusted and would not budge, even with much PB blaster. I did wire brush qand clean the are good and put some high temp exhaust/muffler sealer on it. I'll see if that helps. If it don't then I'll tear it all down later. I would rather get my new rear bushings on now.