Odd tick noise

[Tommio RS]

Hi there ZR-1 Registry.


I come today with a question about a noise my 95 ZR-1 has developed.


Back round of my 95 ZR-1 and info on the noise.


The car is totally stock other than the Marc Haibeck chip
and a x brace.
Work that i have done over the years are speedo drive in the transmission, oil pressure sender unit and rebuilt/ replaced the serpentine belt tensioner and the belt and the spark plugs when i 1st got the car. It had a nasty multi cylinder miss fire when at full operation temp. Plus oil changes.




So here is what the car is doing.
Car is warming up or at full operation temp and it will start "tick, tick" randomly? It will still tick with the clutch in or out. If you rev the engine at all over idle i cant hear the tick. This tick NEVER was there before i parked it for winter and now after winter it has this tick? The way it ticks to me its not top end or bottom end maybe its accessory drive or exhaust related?



Video:
The tick happens near the end.



https://www.youtube.com/shorts/QGyRkbHR2CA

[WARP TEN]

I couldn't really hear a tick so I will let others speculate on its source. If you were driving the car and got a tick, I think I could offer a more concrete suggestion.--Bob

[Tommio RS]

The noise is for sure there in the video it happens 2 times both near the end.
You have to turn up the volume to hear it but its there.



I have not driven the car at all because of this noise. In the odd case that it could be internal to the engine i dont want to risk damaging it more.


Ill see if i can make a better video of the noise soon.

[jw63]

Obviously hard to diagnose from that video as it could be a variety of things, but sort of sounds like a lifter tick?

I had a lifter partially collapse while the car sat over winter and it made a similar sound after starting up.

I'd use a mechanics stethoscope and see if you can isolate a location that the noise is coming from.

[Tommio RS]

Ok!


So i did some stethoscoping when the engine was running.
I scoped the entire engine and i did not hear anything out of the normal, specifically on the valve covers and oil pan in places.


Now the noise from what i can tell is coming from the drivers side exhaust.
Its very loud when scoping at the header flange to the converter. The passenger side is not as loud as the drivers side.


So i think the heat shields on the header are getting loose or starting to "fail".


Also the noise is gone if the car is very hot like 98c and the noise is gone after.



So its a case of old exhaust parts making noise. I will snug up the heat shields and see.


Thanks.

[A26B]

Could be an exhaust leak/bad gasket.

[WARP TEN]

Could be an exhaust leak/bad gasket.

Yep agree with Jerry--that's what I would think from the description. --Bob