My '85 MGM, "Maisa"

[DerekTheGreat]

I'd wager to say white is the most durable pigment out there, aside from black. But black absorbs UV rays and so if you've got a base/clear system, you can say "good-bye" to the clear in short order compared to other colors. White repels UV, it lasts. I never liked white until I owned a white car.

[gadget73]

Ford didn't use base/clear on their white cars until the 90s. Its just straight enamel paint. You will never see failed clearcoat on a white Ford from that period.

[Arquemann]

She's out and about again! And the idle still goes clicketyclack...
She had leaked quite a bit more engine oil during the winter than previous years and even a little bit of coolant, which might be a loose clamp since I changed all the heater hoses last summer.

Number one priority currently is to figure out what the fuck is with the clacking. First I'll check the oil pressure. Trying to find an oil pressure gauge with a sweep that's accurate enough and doesn't cost a fucking fortune.
I did quickly pull the 4 and 8 plug wires this evening, but they didn't seem to affect the noise much if at all.
I'm starting to lean more towards piston slap than a rod knock.

Gotta gather my thoughts and make a to-do list of all the other shit.

Start of season '23, 110070 miles

[DerekTheGreat]

Aside from the center caps, the thing looks better than when you first posted it. That driver's side side marker lens looks NOS, very nice.

If you think the clack is cylinder related, you can unplug a spark plug wire one-at-a-time at the cap. If there is a change, there's your bad news. I'm not the type to recommend chasing unknowns though. These days I'd recommend running it until it blows up, or the problem's identity becomes blatantly obvious.

[Arquemann]

Clicketyclack continued:
- Now installed oil pressure gauge says 30psi on idle in gear, almost 40psi in park. The oil (20W-50) was somewhat warmed up after a 15min drive.
- I pulled the plug wires one at a time and went through every cylinder, no clear change in the clattering on any of them.

While the oil pressure isn't exactly ideal considering its 20W50, it's not that bad. Still a 110k mile 302 with questionable service history.
The oil pressure, the fact that the clacking is only at idle and theres not rhythm or regularity to it, makes me believe less that it would be a rod bearing.
Since it doesn't sound like valve train, it could be a wrist pin or more like piston slap. I saw a youtube video of some guys 302, which made a pretty similar sound. He ended up having a broken piston skirt, causing piston slap.

Currently I don't know what to do... I don't have the facilities or proper money to tear the engine apart and rebuild it. Then again, letting the engine clicketyclack itself to death might cause even more money to be spent later, ie unusable block or crank. I'm not in the US, so spare small blocks don't grow in trees.

Everything except piss is shit.

[sly]

Have you checked for loose bolts on the flex plate/torque converter?
Only other thing I can think of is worn rockers or lifters or slack timing chain.
If any of these things have already been dealt with, ignore.

[DerekTheGreat]

If it was lower bearing related, you'd have found it when you were pulling plug wires. The noise would've went away if it was just one cylinder or reduced itself dramatically if it was one of many.

[Arquemann]

What a lovely day to curse underneath a Ford!
- Terk converter nuts are tight
- Oil level sensor is atleast one thing that leaks, did tighten it a wee bit
- Lower radhose is another thing that leaks, tightened the upper clamp a bit
- Not sure if the rear of the oil pan leaks or if its the rear main
- Removed the pressure gauge and reinstalled the factory sender with thread sealer, the gauge fitting leaked
- Also noticed an exhaust leak on the passenger side, can't see where though

Dunno where to jump next, I guess diagnosing is at an end. Can't figure out what else to check anymore

[kishy]

Exhaust leaks can sound remarkably mechanical in nature, if it's between the manifold and head or a crack in the manifold.

Piston slap is anecdotally a common development with the lopo. I don't think your mileage is high enough to assume that, but anything is possible. It would be fairly ideal though since they can run, again anecdotally, "forever" whilst clacking away happily.

I'd go at it with a stethoscope and see if you can narrow it down that way. If it's loudest on the sides of the block, you've got enough of an answer to at least proceed knowing there's nothing you can do about it at this point in time.

A decent quality video to try to capture the sound would also help us have more perspective, I think.

[Arquemann]

Exhaust leaks can sound remarkably mechanical in nature, if it's between the manifold and head or a crack in the manifold.

Piston slap is anecdotally a common development with the lopo. I don't think your mileage is high enough to assume that, but anything is possible. It would be fairly ideal though since they can run, again anecdotally, "forever" whilst clacking away happily.

I'd go at it with a stethoscope and see if you can narrow it down that way. If it's loudest on the sides of the block, you've got enough of an answer to at least proceed knowing there's nothing you can do about it at this point in time.

A decent quality video to try to capture the sound would also help us have more perspective, I think.

The exhaust leak is coming from somewhere around the pass. side cat. It's an obvious burbly exhaust noise, no mistaking that. Though I'm definitely familiar with exhaust leaks sounding mechanical...

I used a jack handle for some listening last year, but I guess I could try again, less half-assed. Don't have a stethoscope though. Might aswell snag a quick video/sound clip of the clicketyclack.

Is "the lopo knock" a rod knock or just any non-immediately threatening knock from the engine?

[gadget73]

if it has any oil pressure at hot idle, its fine. If its more than 15 psi you don't need 20w50 either.

rod knocks tend to not be audible at idle, but you will hear them get louder around 2000 rpm in park/neutral. If thats not what you have, fair guess its not a rod knock. This also tends to go with low oil pressure since the knock is caused by excess clearance between the crank and rod bearing, which gives the oil a place to leak out.

[sly]

Rear engine leaks are typically valve cover related rather than rear main as that tends to just run down the back of the engine (or PCV grommet being crap and allowing blead out the back - not sure if the 85 has it in the same place as the 86-91, but if it's in the rear of the intake manifold like the later cars, that's another place to look for oil leaks - if in the valve covers, disregard).

[gadget73]

in the valve cover on an 85, not at the back of the intake. Same possibility of intake leaks if that back end wall gasket didn't sit properly though.

[Tiggie]

My experience with piston slap is that it mostly exists at cold idle and goes away with light throttle or load on the engine.

[Arquemann]

My experience with piston slap is that it mostly exists at cold idle and goes away with light throttle or load on the engine.

Well that's what I have, except mine does it on hot idle aswell. It's quiet for about 30 seconds after a cold start and then it starts clattering.

Here's some audio clips (if they work), headphones recommended:

Cold engine, recorded from just behind the front tire.
Left side: https://drive.google.com/file/d/1Rdd...ew?usp=sharing
Right side: https://drive.google.com/file/d/1RdW...ew?usp=sharing
Just under middle of front bumper: https://drive.google.com/file/d/1R_3...ew?usp=sharing

Starting to warm up (behind left tire): https://drive.google.com/file/d/1RnS...ew?usp=sharing
Warmed up (behind left tire): https://drive.google.com/file/d/1SJV...ew?usp=sharing
About the same from the other side, can't tell which side its on by listening.

It's loud enough to be heard by others when I pull into a parking lot. If it's quiet, I can hear it into the car with the doors shut. Hot and cold idle, in park or in gear. It does not have a proper rhythm to it nor is it regular. It disappears on even the lightest throttle input. Engine has to settle back to idle before it clatters when stopping at a light for example.