real time help, exhaust leak or rockers?

[shamrok]

Evening all, I’m on a bit of a road trip and currently on the northern CA coast. Car (‘83 SC) has been running excellent and I’ve been driving it pretty hard without any hiccups. Then I started it up tonight after a beach stop and it sounds like this.

https://youtu.be/b-fh6JApdNs

The clackety-clack gets faster with revs. Power seems unaffected. Valves, guides, lower head studs all replaced last year so I’m stuck thinking it’s my rockers or valve lash (inspected rockers and did valve lash adjustment 3k miles ago) or I have an exhaust leak to my original HEs.

As I’m about 1000 miles from home and on a deadline, I need to know how much stress I’m going to undergo tonight as I nurse a few camp beers.

[356911930]

It wouldn't hurt to try and identify which side of the engine the tapping is coming from. Also, where are you currently located? Someone local to your current position may have gargae space to allow you to remove the valve covers, as necessary, for an inspection.

Anything you are not telling us? Like a missed shift, over rev or overheat?

Rahl

[shamrok]

No missed shifts or over-revs, temps got a bit high a few days ago but never in the red. Currently outside Eureka, CA. It sounds like the driver’s side if I can pinpoint it.

[356911930]

Higher temps should not be a problem.

You might want to start another thread, titled, Eureka, CA Pelicans, need Help!

See if a local can allow you to use his garage to isnpect.

Here is John walkers contact information, He probably has a better ear than I do. I hope thaty are current. Luckily tomorrow is a weekday!
https://www.instagram.com/johnwalker8704
8009 103rd pl ne Marysville Wa 98270
206 637 4071

Any oil leaking from around the lower rocker cover?

Best of luck,

Rahl

[john walker's workshop]

Loose rocker most likely. Should fix it before much more driving. Might get lucky and find it's up top so easy to pop the cover off and redo.

[356911930]

WOW, Thanks John!

I was thinking the the same and hoping it was not a loose rocker shaft!

Shamrock: You will need a 0.1mm (.004") feeler gauge and wrenches.

Best of luck,


Rahl

[shamrok]

Thanks John and Rahl, luckily I brought *some* tools, so will at least pop off the top covers first thing and have a look, but will need a jack or lift to look at the bottoms...hear's hoping!

[john walker's workshop]

In a pinch, you can just do it by feel. Just a tiny bit of clearance as you work the rocker arm. Maybe a nut fell off. Be sure it's on TDC for that cylinder, which can be done by tracing that plug wire to the distributor cap and then turn the engine over until the rotor points to that terminal and a pulley notch is at 12 o'clock.

[shamrok]

Without a distributor (converted to EFI), best guess at TDC for the other cylinders is 120ish degrees off, no? Or it shouldn't matter as long as the cam is rotated enough to not be getting a lobe (eg the back side of the lobe to allow freeplay)?

[john walker's workshop]

Just get the offending rocker on the backside of the lobe then. The crank pulley notch is still there.

[uwanna]

The 3.6 transplant in my '80SC started making an identical noise a while back.
Just like your noise, mine just came on suddenly when I restarted the motor after an oil change. Using a stethoscope the sound seems to be on drivers side cylinder 3 intake.

I have not yet have had time to open her up, so have not been driving her.
Having read several posts on a broken valve spring, they all seem to have the same symptom and sound very much like your and my motor.
Will watch with interest to see what you find.

[shamrok]

Well, definitely not the top side. Sounds like #2 or 3 exhaust side but I gotta get a drain pan. Here's hoping it's not a valve spring...yikes.

[uwanna]

Originally Posted by shamrok

Well, definitely not the top side. Sounds like #2 or 3 exhaust side but I gotta get a drain pan. Here's hoping it's not a valve spring...yikes.

Search broken valve spring posts. Not really that horrible a problem. Springs can
be replaced in situ using a special valve spring compressor available from our host.
I know, easy for me to say, given I haven't done it yet, but quite a few of the posts
have good pics and directions.
Here's a good post for starters:Poll: Exhaust Leak or Valve? Or???

[shamrok]

Yeah, spring looks doable in my garage for sure, but not out here in a random parking lot with minimal tools, heh.

Question for the group, if the rockers check good, valve adjustment is good, do I drive on a possibly bad spring? I saw the tidbit about pushing on the rockers and if they move in easily that it's a good indicator of a bad spring, but otherwise...?

When I drove it last night it still had power, so it's not missing from what I can tell. I can dig into it more at home, but I gotta get it home first.

[john walker's workshop]

Broken valve spring noise is usually noticed as the RPMs get up there. Not generally at idle/low rpm.

[uwanna]

Originally Posted by john walker's workshop

Broken valve spring noise is usually noticed as the RPMs get up there. Not generally at idle/low rpm.

John,
The video from this thread that had a broken valve spring has a pronounced noise
at idle. Thoughts?
Poll: Exhaust Leak or Valve? Or???

[proporsche]

I`d second that...since this happened after driving broken valve spring....is more likely the culprit
To Shamrok take it easy on the driving also to locate the problem use a screwdriver and listen to each cylinder by placing the tip to the intake pipe...

[ADDvanced]

Sounds like an exhaust leak to me?

[john walker's workshop]

Check to see if all 6 smog port plugs are still in place just above the exhaust outlets. Sounds more clanky than exhaust leak, but maybe.

[Synchro Joe]

You can try a decent local shop there, Hubbard's German Auto Service, probably best to call them first
707-443-4496, my brother tells me due to COVID they don't like walk in's as a rule.
Hubbard's European
235 West Grant Street
Eureka, CA 95501