Help Diagnosing 1986 C4 Engine Noise

[DS75]

I need help determining what an engine noise I’m hearing is.

I’ve slowly been bringing my C4 back to life after letting it sit for a several years. Over the past 18 months or so I replaced the radiator, alternator (and battery), spark plug and cables, water pump, and a bent driver side universal joint/ half shaft. Now that Humpty Dumpty is back together again I’m noticing a loud ticking at start up that persists but does get quieter after getting upto temp (215-225F on the coolant). This was likely there before and I just didn’t notice but now do.

The sound comes from the driver side of the engine. The first video is from shortly after start up, the second from 10 minutes later after warming up. Conditions are at idle, 700 rpm; AC/htr off; fresh oil/filter; fan thermostat on coolant kicking on at 225F and off at 215F.

I’m guessing this is not a totally normal noise so trying to determine if it’s a big problem and how to figure out what needs to be fixed to correct it. From my uninformed ear it sound like a valve but IDK.

Thanks!

 

[Shelby]

Hi, To me, it sounds like a loose rocker arm, if the valve cover gaskets need to be replaced, you could see if the they are loose, to me agine it only sounds like one rocker arm is loose. If you were to find one and you wanted to adjust it, you have the engine running and up to temperture, back off the one rocker, once it starts to loudly tap, tighten it till the tapping is gone, turn in one half turn and then do each one the same way. I would think it's been there for a while and you only are are hearing it now since you have not used the car in a while. If your not comfortable with doing it yourself, find a well trained mechanic and let them do the valve adjustment.

 

[GWinter]

hadn't been on the site for a few weeks and just saw this post, I totally agree , very lose rocker.The rocker getting lose has to have a cause would check to see if the nut on it is quite lose when you turn it, a new nut might be wise. . if it isn't running real smooth there is a chance you have a lobe on the cam worn down. Post what you find may help someone else.

 

[Shelby]

If the car hasn't been used enough, you might want to fluch the oil and filter a few time to clean out the lifters ?