Engine noise!!! HELP! VIDEO!!

[IronManEx]

Need some help can't figure this one out on my own..

So I have a 2003 Ford Explorer XLS
Bought with a bad servo, did the $100 repair and it ran great!
4.0 SOHC V6 5R55W auto..

I ran it cold one day on lunch at work on a slightly warm day. Started it up and made it about... 50ft before it started to knock loudly. No shaking, no loss of power, no engine codes ect..

Parked it and tried to pretend it didn't happen.. Changed the oil an filter and prayed to the car gods it was gone. Well it isn't..

It did however get substantially quieter. I will do my best to describe the symptoms and attach a video.

The sound is consistent to what I'd believe to be either wrong with one cyl OR something with the timing?? It is consistent BUT not frequent.. It is directly related to engine RPM, and not vehicle speed or load. Revving and driving it makes the same sound, and tone, and volume. I have no loss of power, no mixed fluids, and no weird smells or smoke.

THERE ARE NO CHECK ENGINE CODES.

The noise appears to come from the bottom of the drivers left bank. Using a mechanics rod I could hear it predominantly in the cat converter.. reverberation through the entire engine and transmission consistently..

I first changed the oil
then checked all the spark plugs
then I did a compression test on the drivers left banks and they were all very very close to each other..
after that I check all the spark
checked for codes, and reset the pcm
after that I ran a can of seafoam through it

So far nothing has made much of a difference.. It runs fine. The sound is hard to hear inside the cab with the windows up. but with the window down it can be heard driving near anything sound deflective. When you are looking at the engine it is very obvious there is a noise. It's not really a grinding, or whirring noise, but just a.. tap... tap...tap...tap...tap... Warm cold, reved high low ect it makes the same sound.

The manifolds look clean, I don't seem any blowby, and the studs/nuts are actually pretty damn clean for the year, though I have not put sockets on them to test them.

Looking for any advice, I will try to attach the short video I made while it was coming up to temp. Thanks guys, appreciate the site and the advice

https://www.youtube.com/watch?v=tSJccYtu2GQ&feature=youtu.be

 

[Tommylee1282]

You checked all the heAt shields? I would say something could be broken in a cat but I would expect some lose of power or loud exhaust...run it with the serpentine belt off to better pin point the problem

 

[vroomzoomboom]

i vote rod on this one

 

[morbid81]

Did that thing say 9435xx on the odometer?

 

[IronManEx]

You checked all the heAt shields? I would say something could be broken in a cat but I would expect some lose of power or loud exhaust...run it with the serpentine belt off to better pin point the problem

I will pull belt after work tonight and try that, the only thing holding me back from thinking it may be the cat is the noise is so linear with the motor. There is a rhythm to it that increases with rpm. Will a broken cat sound like that? Is it common for explorers to have this issue?

Did that thing say 9435xx on the odometer?

Probably 94,350 haha.


I'm really hoping it's not a broken rod
I did the compression check and it seemed to check out?? Was my understanding compression diagnosis would give you the health of your bottom end? If it is a rod, what are my options?

 

[Tommylee1282]

If the cat has something broken rattling around inside it or is restricting flow of the exhaust then it will match the rev because your creating more exhaust that can't get out...but the o2 sensors would notice the difference in psi before and after the cat and take away a lot of your pickup...I had a broken muffler that rattled when I hit the gas and somehow let very littles exhaust out so it would take me close to a minute to get to 60mph and the exhaust was pretty loud...def try running it with the belt off and see if it's coming from inside the engine

 

[vroomzoomboom]

sorry, i should say rod has eaten a bearing and now has movement between the rod and crank. lets hope i am wrong however

 

[MrWizard]

Did you ever pull the serpentine belt briefly and see if the noise is still there?

If the noise goes away w/o the belt, it may be a bad A/C clutch bearing.
You'd be surprised how loud they can be when they go bad.

 

[FR-425]

Sounded like a cracked flex plate to me.

Possibly the starter ring gear on the flex plate cracked.

Pull the starter out and have a look.

 

[Turdle]

^^ I vote this or a connecting rod

I moved this thread to the stock 4th gen sub forum.

 

[scotrinaf]

That is a seriously clean engine for an 11 year old ride... I'm thinking a broken bearing in a pulley on the lower side of the engine...

 

[gmbroy]

Sounds like lifter noise But the first thing you should do is to pull the starter & check the fly wheel & ring gear as fr425 suggested . I do very much trust his opinion on things !!

 

[Flag Gibby]

^^ I vote this or a connecting rod

I moved this thread to the stock 4th gen sub forum.

Turdle... The vehicle in question in this thread is a 2003. Doesn't really belong in 4th gen. stuff does it?

 

[Turdle]

Turdle... The vehicle in question in this thread is a 2003. Doesn't really belong in 4th gen. stuff does it?

Thanks for catching that

Thread moved--again.

 

[engineeering]

sounded louder at the bottom of the engine judging by the video... I could be wrong. Try using a stethoscope (or red-neck screwdriver/palm to ear method) and try to pinpoint the noise from the bottom. This might help narrow it down.

 

[IronManEx]

I did use a scope as I said it's most loud at the drivers cat. I pulled my valve cover to check for a lifter today after having it sit for months.. I didn't find any lifter issue however found a nice chunk of chain guide setting next to the cam. I'll be pulling the engine this week to inspect it.. unless otherwise advised.

Before I pull it will obviously check through the starter as it needs removed to pull the engine anyways. I'm hoping this is a timing chain issue and I can slap some new chains and guides all around and move on.

 

[Bobmbx]

I did use a scope as I said it's most loud at the drivers cat. I pulled my valve cover to check for a lifter today after having it sit for months.. I didn't find any lifter issue however found a nice chunk of chain guide setting next to the cam. I'll be pulling the engine this week to inspect it.. unless otherwise advised.

Before I pull it will obviously check through the starter as it needs removed to pull the engine anyways. I'm hoping this is a timing chain issue and I can slap some new chains and guides all around and move on.

Do yourself a favor while you've got the engine opened up. Try to 're-assemble' the plastic pieces for the guide(s) to make sure you got'em all. Otherwise, smaller pieces will rifle around the engine and eventually end up blocking an oil port or two...or three.

 

[rodknock95]

sounds just like my expedition did when the cam phasers started going out.

 

[xhomerjayx]

Sounds like your timing chain guide has bought it. please know that there are 4 chains on the 4.0L v6. I had the same sound, and had the chains done, but ended up rebuilding the entire engine as the cost differential was about 400 bucks.

 

[IronManEx]

The engine assembly came out easily. After pulling both covers and turning the motor I think I determined a bad tensioner, when cycling compression once a rotation the tensioner (?) Located next to the can on the top of the head that had a piston inside of a threaded insert through the head; behaves irratically.

After that I pulled the pan, found multiple pieces of chain guide chewed up... As well as a metal spacer??? Not sure what it is to be honest. I'll attach a photo.

Should I pull the aluminum from the bottom of the block and check for crank damage? Is it part of the steps for changing all the guides and chains? I'm gonna dig into tutorials on the kit now, if anyone has links awesome.
Thanks for all the suggestions guys.