Need help finding a rattle

[weeegoneeer]

Hey guys - could use your help in case any of you have run across this before, sorry for the novel-length post!

I took my rig for a trip from Portland to Boise and back a few weeks ago, truck was running awesome. Spent most of the highway miles between 75-80MPH, a little over 3000 RPM.

- When I got back to Portland, I noticed that a rattle has developed. Also, my oil was much grayer than it should have been.
- The rattle is rhythmic, sounds to be 2x the speed a cylinder would see spark. I have a little pressure gauge on my fuel line that pulses with the fuel pump, seems to be going the same speed as the fuel pulses. Fuel pressure centers around 5psi.
- Drained the oil, magnetic plug had a nice little mushroom of filings on it
- Took apart my oil filter (it's one of those reusable ones), and had a bunch of metal on the internal magnet.
- Had a bunch of shavings that didn't make it through the filter element as well but didn't stick to the magnet (maybe there was too much stuff already there?)
- Pulled valve covers, measured lobe lift - checked out A-OK (within 0.002 for all but the exhaust on #1, which was 0.008)
- Pulled intake to see what's what, had on slightly dished lifter on #1 (barely). I also noticed that I had no preload on most of the lifters.
- Pulled rocker arms, some were extremely worn. Replaced rockers & got preload when installing.
- Pushrods are correct length and not worn.
- Oil pressure is awesome - 50psi warm in idle, 70psi @ 2000RPM.
- Dizzy gear shows normal wear patterns (not much at all).
- Still have plenty of power.

Couldn't see any obvious culprit for the metal shavings, so stitched it all back together & fired her up. Still have the rattle.

Then did what I should have done in the 1st place, and listened with a stethoscope (with the contact wand). Rattle is not coming from the valve covers, intake or the block by the plugs. It is super loud on the dizzy clamp, and also fuel pump.

Tried to take a video so you can hear it, but all my phone picks up is wind from the fan.

What could be the culprit? Could it be the fuel pump? Would that explain the shavings?

I can start pulling stuff apart blindly, but if you guys have advice on what to look at 1st am all ears.

Thanks for your time!

[BCRAWLER]

Thinking maybe the egg shaped unit activating the fuel pump. If I remember it is made of aluminum and filing would explain color of grey in oil.

[babywag]

the fuel pump eccentric is not aluminum.
a fuel pump can make noise pull it and see if arm is excessively loose?
remove belts and eliminate water pump as noise source?

if those aren’t it, time to pull cover, timing chain maybe very worn/stretched out?

[weeegoneeer]

Thanks guys! I'm pretty sure that the waterpump & timing chain are OK, have 20,000 miles on a rebuild and timing mark is really steady. Will start by pulling fuel pump & report back!

[weeegoneeer]

Confirmed it's not the fuel pump! It has quieted down a little after replacing it though. The sound is almost imperceptible at idle, sounds like a ticking lifter (though it's confirmed it isn't). When I accelerate it gets louder - and the tone almost changes from a tick to a rhythmic metal scrape.

Also confirmed none of my torque converter bolts are hitting the the tin around the inspection cover.

Any other ideas?

[babywag]

Never assume parts are good @ least that’s what I have learned over years. Even brand new parts can be bad.

I’ve seen water pumps that seemed ok w/ belt(s) on, but when removed loose as hell.
I’ve seen crud stuck inside housing, I’ve seen implellers rub on covers.
I’ve seen low mileage timing sets w/ very sloppy chains.
I’ve seen distributors w/ worn out bushings.
Point being noises can be caused by anything.

process of elimination remove anything that can cause noise until either noise goes away or you can pinpoint an origin.
Other thing didn’t notice until now is your hot oil pressure is way too high. 50psi @ warm idle is ~double what it should be.

[letank]

- Oil pressure is awesome - 50psi warm in idle, 70psi @ 2000RPM.

As said above, if the pressure is too high, it means that very little oil flow is going to the areas to be lubricated, hence heat is not removed in an efficient way... BUT as usual is that pressure real? You can test the accuracy of your electrical oil pressure gauge, use resistors of these values of .... need to recheck your vehicle year... OK, this is an 84 so putting the following resistance between your gauge sender wire at the engine and a good ground : the gauge will give you the following values ,the middle of the gauge is reach with a resistor of 25 Ohms, High pressure is about 15 ohms and low pressure in the 78 ohms.... need to recheck those numbers

Edit on saturday 10:35am, it is recommended that the system be at operating temp, so watch for scalding when pulling the sender wire...

you can use this home made device -NEED to find device pict-



The grey oil is also not good... usually the oil turns brown, the only grey oil I have seen is when the fuel pump or a few spark plugs fail and gas is dumped into the crankcase washing the engine parts...

[weeegoneeer]

Thanks letank! I’m sure my oil pressure is accurate - confirmed with a mechanical gauge. Also, the oil doesn’t smell like gas at all. Going to pull the distributor later this week to see if I can see anything inside the timing cover with an inspection camera. If everything looks good there, going to pull plug wires one at a time and see if the sound goes away.

[Stuka]

You could also have a small amount of water in the oil. Are you by chance running non-detergent oil? It’s always gray.

Also, your oil pressure should never get that high. There is an oil pressure relief spring that should act as a bypass way before it hits 70psi. What weight oil are you running?

[weeegoneeer]

Hey Stuka!

Was running Amsoil Z-Rod 5w30. The oil was gray with non-magnetic metallic looking particles, picked up quite a bit of magnetic particles on the oil filter magnet & on the magnetic drain plug. Didn't look like an emulsification. Something clearly went sideways in there.

Also - I rounded up to 70psi, the actual is somewhere around 65-68psi... I think the pressure release spring is rated for 60 so I'm not that far off, but yeah - it is high.

I'm running el cheapo napa 10w40 (Like $2.50 a quart on sale!) in it now to get a few quick oil changes in to hopefully flush some metal from the oil, and I'm now getting more normal pressure readings when hot. Still up to 60 when in higher RPMs, but idling it's down to 35ish.

I have family in town this week & am starting a new job, but this weekend will remove belts to try and get a good recording minus fan/wind noise.

Driving me nuts because I've made the Portland-->Boise ride many times on hotter days, and in general drive a lot and for long distances. It's frustrating when all of a sudden stuff like this happens with no changes or no warning.

I truly appreciate everyone chiming in with their 2¢ - will have another update this weekend!

[candymancan]

Just to chime in oil pressures... Mine is about 30-40 in park... and 20 in drive and when driving im getting 50-60. Im using 0-40w europeon oil.. If i use 10-30w oils its a little lower at idle drive its more like 10-20 but still 50 when driving. And tea call me nuts on using 0-40 but i found its ALOT quieter using 0-40 then 10-40 or 10-30 when starting.. My Jeep always has this loud clanking noise for the first 100 feet or so so i went to a thinner cold start oil to get better lubrication and it worked

Granted oil pressures vary on temps... temp gauge means nothing my oil pressures i mentioned are when its been driv8ng for like 30 minutes or more thr longer you drive the hotter the oil gets and pressure goes down a little as it thins up

[weeegoneeer]

Update!

So, pulled the distributor out and took some pictures as best I could inside the timing cover. Looks like the camshaft distributor drive gear has a little damage - could this be causing the ticking?

With a stethoscope using the contact wand, the tick is loudest on the fuel pump & distributor hold-down clamp.

Also, I was wrong before, all of the shavings are magnetic, so we're not looking at an aluminum part.

Anyway, thanks as always for your input!

[weeegoneeer]

Update:

Pulled the cover off today and found that when my engine was rebuilt, they neglected to install the oil slinger on the end of the crank. What would be the negative effects of not having it installed? Going to email the rebuilder and see if they can send one out to me.

Also, the timing set looked good, chain not stretched. No obvious broken teeth or anything.

Camshaft distributor drive gear looked pretty bad. Some of the ends of teeth were a little broken off, dings and dents as shown in the photo I posted previously.

I have an OEM distributor gear set from a spare 360 I'm going to install. It's in pretty good shape.

If anyone can tell me what effects the absence of a slinger would have, awesome.

Thanks all! Just want to get another 10,000 miles out of this engine while I rebuild the spare...