My '85 MGM, "Maisa"

[Arquemann]

You have tried the long metal object or a auto stethoscope to isolate this?

Kinda louder from up top, all along the length really. No definite location.

[jaywish]

So you tried an auto stethoscope and it could not be isolated?

[Arquemann]

So you tried an auto stethoscope and it could not be isolated?

Used a tire iron, couldn't isolate it with that. Putting it on a head is louder than the intake, but the heads are quieter than the block. Front to back basically no difference, maybe a bit quieter all the way back.
Laying underneath the engine seems quieter than having my head close by up top.

[sly]

Sounds cam related by sound intensity... lifters are right there. Seems to point to the current theory.

[Arquemann]

Inspection passed, just one complaint; frame VIN is almost illegible. Shouldn't be much work to make it a bit better to see.
Inspector wasn't particularly fond of the noises my engine makes either, joked about an unapproved change of fuel type.

Yesterday I took off the driver side valve cover after running for a while, rockers were all tight, so nothing obvious wrong. Though the rockers were quite uniform in angle, I guess the rockers under spring pressure bleed down pretty fast.

Since the rattle doesn't seem to be going anywhere, I think I'll get the TV cable adjusted properly, tune the carb a bit and get some more miles on the engine. Then change the oil, back to 10W30 see what it does.

[friskyfrankie]

Curious to see what the change in viscosity does too. Doesn't sound like a gas/octane issue - too bad as that would be an easy fix!

[Arquemann]

AOD: adjusted
Belts: tight
AC: cold
Weather: hot
Inspection: valid
Rattle: yes
Car: filthy

I think it's time for the first cruise night with her.

30°C weather plus me romping on it for probably 20 minutes straight, oil pressure was down to about 40-45 psi at low idle, even with 20W50. Though that'll probably be as hot as it'll ever get.
I have a feeling the reman dizzy isn't doing timing things very nicely, I'll have to check and verify the vacuum & mechanical advance soon.

[Arquemann]

First run didn't go quite as well as I'd have hoped.
It idles low and lean now for some reason, more now than earlier today. Had to two-foot it most of the way out of town on the way home. Highway afr is fine, though it feels oddly sluggish at those speeds.
Definitely will have to check the operation of the distributor advance mechanisms. And check for vacuum leaks, if none found I'll re-set the idle mixtures.

[sly]

+1 check the distributor advance and make sure it's not locked in the advanced position (or just flopping straight out).

I like carbs for the easy adjustments, but I dislike them for general troubleshooting. I don't miss dealing with them until I have computer failures and a screwdriver would be able to "get me home" with a carb. I think you're on the right track though.