TRayman

I got the truck back from my son several months ago (close to a year). While he had her, she sat for several years (5 or maybe 7??) and has 320,xxx miles on her.
Since getting her back it has been item after item. Lol thank god I am doing this because I love her and not because I need a truck (I don't, really).

I put a starter in 2 weeks ago because she refused to start at a home depot and a new noise started immediately after that. That was also the first time I had taken the truck out on the highway or more than 20 miles since I got it back to be road worthy. Put in a new power steering pump - which the old one was making bad noises and I though was the source of the new bad noises. Turns out there are more bad noises than I realized.

SO after chasing around some I think I have a stuck lifter. The noise sounds similar to a handful of bolts in a coffee can being rolled around and varies a little but not much with engine RPM. It sounds strongest from the back of the engine near the firewall. A lifter or bent push rod is the only things that make sense to me. I have not done a compression test or any other testing other than just a good listen with a stethoscope. A compression test would probably be very informative.

I have not torn anything down yet because I wanted to order parts first. I have never replaced lifters or push rods and it looks like you cannot just order the "stock" push rods? Every time I look at a description of one the lengths vary. Some say 7.9 inches other say 7.87 inches.... Some even different lengths than those.
How do I know what to order or do I just have to tear it down and measure the push rods for myself? It is a stock engine to my best of knowledge. I bought her used with 70,XXX miles. I would think there would be a "stock" length.
I figure while I am in there I will do springs, push rods, lifters, and all the gaskets that I can imagine. Anything else I should do while I have the valve cover off?

raski

I would not order any parts or tear it down until I did some testing with it first. I would definately check compression and see where you stand with it. I can't remember when I last heard a noisy lifter, not very common. You could try a chemical in the oil if you believe there is a stuck lifter. Could be a cat.converter with busted up internals too.Could be one of many things and I wouldn't go guessing on it.

Steve83

I agree - don't guess or order parts. Diagnose. A stethoscope is an excellent non-invasive tool, but it's just a start.

Next time the engine is due for an oil change AND cold, pour 2 cans of Berryman's B-12 for gas engines into the crankcase through the oil fill, and run the engine at high idle (~2000RPM; don't drive) for ~15 minutes.
Then drain the oil. I highly recommend swapping to a drain valve like this:
Put on a new MotorCraft FL1A (with about a pint of oil poured in before installation)...


(phone app link)

...and put the rest of 6 qts. into the oil fill. Choose the weight based on the climate between now & the next oil change, as this TSB advises:


(phone app link)

Flushing the engine may solve or reduce the rattling sound. But even if it doesn't, it'll make the engine easier to work on later, by removing most of the internal deposits.

B12 is also good in the gas tanks.

TRayman

Here is where I am at now.
I am STILL curious about how you know which push rods you need and how they are measured but apparently different companies measure them differently soooo that is probably an extra layer of confusion I do not need right now.

Compression (measured stone cold) is between 115 and 135 on every cylinder - a little low but not shocking for a 320,000 mile engine..
I pulled the plug wires one at a time while it was idling and no single plug wire made any difference to the idle. I would have expected that if there was a dead cylinder it would bog the engine down or stall her if you killed second one.
Step on the clutch - no significant change.
Put her in gear and move her - no significant change.
Rev her up at the throttle boy linkage - no significant change.

I have not put the b12 in her yet but I am thinking it will not change anything.
You think I just have something loose somewhere that I cannot find - well not yet.
Today I will go around and tighten everything I can find and maybe get lucky.

I KNOW she has an exhaust leak where there is a bolt that works itself loose every so often. It has never sounded like this before.
How would you test to see if it is a catalytic converter that has rotted out from the inside? Wrap it is wet towels and see if the sound deadens? I know that is how I test my motorcycles for exhaust leaks at joints.

Steve83

Stethoscope, and read this caption:


(phone app link)

TRayman

Thank you!

TRayman

OK more info.
It is NOT the cat. I poked around with the stethoscope more and it sounds like it is coming from the block or transmission. That is where the strongest sound is. Which is not helpful because metal carries sound waves all over. I pulled the starter and inspected the inside of the tranny bell-housing with a micro usb camera. There was nothing there and flywheel teeth are not chewed up.

Also I noticed that it only makes the noise while running. While cranking it does not do it.

I pulled the intake and valve cover.
I watched the valve train as my son turned the key to engage the starter (with no plugs in it). Where should oil be coming from? There was plenty of oil all over everything I just did not see any fresh oil coming up and I expected to. I figure I am looking in the wrong place.
One of the push rods is not spinning - with 320,000 miles on it not shocking. I Googled it and they say it could be Cam going flat, bent push rod, or stuck lifter. The push rod goes up and down just like the others do and seems to have about the same range of motion. I did not make time to pull the push rod and test it for straightness (roll it on a piece of flat glass is how I was told to do that).
How would I tell if the cam is going flat?

Steve83

Everything does, but everything also damps vibrations (to varying degrees). So the farther you get from the source, the quieter the sound will be. There's metal-on-metal contact from the fan blades to the rear lug nuts, but you can't hear the fan by listening to the lug nuts.Top of each pushrod weeps into the rocker, and runs down the valve.


(phone app link)That might just be because it has slightly more friction to the non-rotating rocker than to the rotating lifter (HLA). Alone, it doesn't prove the HLA isn't rotating.My Bronco's 4.9L has a million miles and still runs like-new.By measuring lift at the rocker with a dial indicator.