Jump to content

New Engine Noise


Recommended Posts

Interesting idea. Something like that had occurred to me. On that same drive I hit a pretty gnarly pot hole so in the back of my mind I keep thinking that something broke and what I'm hearing could be outside the engine. Like a motor mount rubbing metal or something like that. I haven't looked closely at the exhaust though. Not sure how well I'm going to be able to see anything on that rusty header, but I'll give that a look and see if that gets me anywhere. 

Along those lines, had a couple neighbors pontificating on this and they came up with two solutions. 1st, get a louder stereo and 2nd run it with open headers. :classic_unsure:

I'll poke around out there this evening. Thanks for the idea. 

 image.png.c5a82cdc270542869e213815ec368140.png   72 Fastback - 351C-4V, Fitech EFI, T56 Magnum 6 Speed, FiTech EFI, 8.8 / 4.10 LSD Rear end, discs all around. Fancy rattle can paint job. 

Link to comment
Share on other sites

Dude, both the tiny exhaust leak and motor mount sound like possibilities.

Any chance you could secure your phone in the engine bay to take a recording while letting the clutch out while in gear and listen to your recording and compare to the previous ??

Safety first !!!

  • Like 1
Link to comment
Share on other sites

18 minutes ago, boilermaster said:

Dude, both the tiny exhaust leak and motor mount sound like possibilities.

Any chance you could secure your phone in the engine bay to take a recording while letting the clutch out while in gear and listen to your recording and compare to the previous ??

Safety first !!!

So I had my wife stand in front of the car while I dumped the clutch and noise doesn't change (the engine I mean :classic_smile:). And just kidding, she's awesome and the noise when it's happening is usually loud enough to hear from inside the car. Naturally this time it wasn't making the noise at all so wasn't able to test. Usually if I shut it off then start it back up in a little bit it will make the noise again. It's too late out here to do that much without pissing off the neighbors so I'll have to do that tomorrow. 

Can't get much a look at the header from up top, so might have to put it up in the air to get a look from underneath. 

 image.png.c5a82cdc270542869e213815ec368140.png   72 Fastback - 351C-4V, Fitech EFI, T56 Magnum 6 Speed, FiTech EFI, 8.8 / 4.10 LSD Rear end, discs all around. Fancy rattle can paint job. 

Link to comment
Share on other sites

Even though it sounds more in the valve train it could be a rod bearing.  Try loosing the plug wires at the distributor so you can pull them out easily.  Start the engine and using a pair of pliers pull one at a time and see if the knocking goes away or quiets down a lot.  If so then more than likely you have a rod bearing going out. 

  • Like 1

Kilgon

 

 

"The only dumb question is the one not asked"

Link to comment
Share on other sites

17 hours ago, Kilgon said:

Even though it sounds more in the valve train it could be a rod bearing.  Try loosing the plug wires at the distributor so you can pull them out easily.  Start the engine and using a pair of pliers pull one at a time and see if the knocking goes away or quiets down a lot.  If so then more than likely you have a rod bearing going out. 

Don't want to get you worried and more than likely it isn't a rod bearing but I would still pull one wire at a time and see if the noise changes.  If so then at least you know what cylinder it is coming from  and can proceed from there as far  as what is causing it.  If no difference then it's one more thing you can cross off the list.  If no change then it might be time to pull the timing chain cover and  see what you can find there.

Kilgon

 

 

"The only dumb question is the one not asked"

Link to comment
Share on other sites

Thanks. This has been in the back of my mind since the beginning as my google searches for short blocks would bear out. I'll be trying the plug thing hopefully later today. While it's not a great time for me to rebuild or replace an engine, I need to get it figured out one way or another. 

Thanks again for the ideas and regardless of the results, it's more info than I have right now. 

 image.png.c5a82cdc270542869e213815ec368140.png   72 Fastback - 351C-4V, Fitech EFI, T56 Magnum 6 Speed, FiTech EFI, 8.8 / 4.10 LSD Rear end, discs all around. Fancy rattle can paint job. 

Link to comment
Share on other sites

Yes, good idea to get it figured out before something lets loose and you need a new block, oil pan, etc.

One thing you might do is to pull off the oil filter and dissect it, see if there is any metal in it, use a magnet to check for steel or iron particles.

  • Like 1

 

 

“If you can't explain it simply, you don't understand it well enough.”

--Albert Einstein

 

Link to comment
Share on other sites

Well yesterday it wouldn't make the sound. Today it's louder than it's ever been and louder in person than the video sounds. At some points it sounds like marbles floating around under the valve cover. 

https://photos.app.goo.gl/G5Yj9agWH4Ry1SCs9

It definitely changes when you pull the wire on #5 (front most on the driver side. Doesn't go away like the videos I've seen of testing rod bearings, but does cut down that loud snapping or clanking sound. 

 

 image.png.c5a82cdc270542869e213815ec368140.png   72 Fastback - 351C-4V, Fitech EFI, T56 Magnum 6 Speed, FiTech EFI, 8.8 / 4.10 LSD Rear end, discs all around. Fancy rattle can paint job. 

Link to comment
Share on other sites

The way it changes with the #5 wire pulled makes me think you have a header gasket leak. 

What do you have for valvetrain? Is your vacuum reading steady? 

 

Here's an example of a rod bearing that's bad., you'll typically hear it under the car, not as much above. 

  • Like 1

 

 

Link to comment
Share on other sites

Boy am I going to feel dumb if this is just a loose header bolt or something like that. Thought I checked that, but now I don't think I actually did. I'll check later and would love to find out that I'm just an idiot and nothing is actually broken. Also getting a little borescope / endoscope so I can get a better view of the headers and inside the fuel pump opening. Roller rockers up top, a video higher up in the thread shows this without the valve cover on. Haven't checked vacuum, but I'll have a look later. 

I pulled the distributor yesterday to check for anything obvious there. Not sure what I'm looking for exactly, but seems OK on the surface. Some up and down play that looks like it probably should be there and solid left / right on the shaft. Bearing is quiet and smooth. No chunks or parts coming out of it or anything. 

 image.png.c5a82cdc270542869e213815ec368140.png   72 Fastback - 351C-4V, Fitech EFI, T56 Magnum 6 Speed, FiTech EFI, 8.8 / 4.10 LSD Rear end, discs all around. Fancy rattle can paint job. 

Link to comment
Share on other sites

After re-reading your entire post I still have not seen where you have checked the valve lash?  I would take a few minutes and at least check it on cylinder 5 if nothing else.   I would  also bring it to tdc and see if you can push down on the rockers and if so how easy does it go down.  As mentioned above check the header gasket and If there is no issue there I would then get your endoscope and look down in the cylinder.  Try to have it at the bottom of the stroke.  See if everything looks ok on the piston and the cylinder walls are fine.      

  • Like 1

Kilgon

 

 

"The only dumb question is the one not asked"

Link to comment
Share on other sites

  Newby  here but wanted to chime in on that noise.  I noticed in the video your running the roller rockers with roller tips on them,  are they the bushed style or individual needle bearings on the fulcrum?  I've seen a lot of these aftermarket  rockers develop cracks around the fulcrum area - some of the aluminum ones I've seen from china with roller bearings are pretty soft aluminum and have no liner between the rocker casting and the small needle bearings and they wear out the aluminum castings developing a lot of slack on the rocker.      

The other potential is the roller tips on them,  if the pin is not sufficient or hearty enough it can distort, bend or wear in the rocker casing,  especially if your running a pretty high lift cam  or have high spring seat pressures.

I would check your valve train as others have advised.  Sounds like valve train noise especially as it has been progressing in your videos from what I can tell.  If nothing else it would give you a chance to check the rest of the valve train - push rods, colasped lifters and such.

  • Like 1
Link to comment
Share on other sites

Thanks, for the feedback.

OK, I was sort of hoping this thread would die and I even considered deleting it, but to hopefully save the next dude some time, Here goes...

My name is The Dude and I'm an idiot. 

That crazy sound that changed all the time and I spent hours taking crap apart, poking, prodding, stressing on, in the back of my mind thinking I might need to rebuild this thing and wasting your time on was....

A header bolt fell out and another couple were loose. 

There I said it. I'll be turning in my tools now. 

giphy.gif

  • Great post!  Let me buy you a beer (or coffee!) 1
  • LOL 1

 image.png.c5a82cdc270542869e213815ec368140.png   72 Fastback - 351C-4V, Fitech EFI, T56 Magnum 6 Speed, FiTech EFI, 8.8 / 4.10 LSD Rear end, discs all around. Fancy rattle can paint job. 

Link to comment
Share on other sites

2 hours ago, TheDude said:

Thanks, for the feedback.

OK, I was sort of hoping this thread would die and I even considered deleting it, but to hopefully save the next dude some time, Here goes...

My name is The Dude and I'm an idiot. 

That crazy sound that changed all the time and I spent hours taking crap apart, poking, prodding, stressing on, in the back of my mind thinking I might need to rebuild this thing and wasting your time on was....

A header bolt fell out and another couple were loose. 

There I said it. I'll be turning in my tools now. 

giphy.gif

:lollerz:   I can't help but laugh.  I love your line "My name is The Dude and I'm an idiot". :rofl:    Best laugh I have had in a while.   We have all been there at one time or another so don't beat yourself up over it.  At least it was nothing serious and an easy fix.  Glad to see you are up and running again.  It was a good learning lesson for us all.

Edited by Kilgon
  • Like 1

Kilgon

 

 

"The only dumb question is the one not asked"

Link to comment
Share on other sites

You are not an idiot, trust me I know some who are. Exhaust leaks can be real foolers, guess how I know. I'm glad it is an easy and cheap fix. Chuck

  • Like 1
Link to comment
Share on other sites

A couple people here did mention exhaust holes and the like (thanks!) and I crawled around under the car, poked around etc. and didn't find anything of course not ever noticing the actual bolt not there. I had just tightened up the header bolts about a month before this so didn't even occur to me that they might have loosened so fast. It just never sounded like the exhaust to me until the very end as it seemed to be getting louder and louder as time went on. This was all in the driveway as I wasn't going to be driving this thing like that. 

On the plus side I did do a bunch of maintenance and little stuff along the way so it wasn't all wasted time by any stretch. 

And, yeah, we've all made dumb mistakes like this. But we don't generally have a thread dedicated to them. :classic_wacko:

  • Like 1
  • LOL 1

 image.png.c5a82cdc270542869e213815ec368140.png   72 Fastback - 351C-4V, Fitech EFI, T56 Magnum 6 Speed, FiTech EFI, 8.8 / 4.10 LSD Rear end, discs all around. Fancy rattle can paint job. 

Link to comment
Share on other sites

4 hours ago, Bentworker said:

Slap some Nord Lock washers under your header bolts and be done with loose bolts.

 

https://www.nord-lock.com/nord-lock/products/washers/

Since I'm missing a bolt and really need to replace a few of them either way, I ordered some of these which look like they use those washers https://www.proformparts.com/product-detail/66756/wedge-locking-header-bolts-hex-head-3-8-dia-x-1in-blk-oxide-finish-16-pcs

And glad my stupidity can bring people some enjoyment

 

  • Like 1

 image.png.c5a82cdc270542869e213815ec368140.png   72 Fastback - 351C-4V, Fitech EFI, T56 Magnum 6 Speed, FiTech EFI, 8.8 / 4.10 LSD Rear end, discs all around. Fancy rattle can paint job. 

Link to comment
Share on other sites

Dude! don't beat yourself up! Remember we all are a bunch of "Dudes" who love wrenching on these sleds. $h*t happens and I personally am very glad you started this thread and shared. We followed and were right there with you. Some of us were trying to learn others with more experience were trying to help. We live and learn and sometimes we laugh at the silly simple things but it's all good bro. I wish I could have been there to see your face when you discovered the cause. I think we would have both laughed at your expense and then brother, I would have bought you a few beers and kicked back. We are all friends here man.

  • Like 1

Just remember John Wick didn’t kill all those people for a random car. It was a Mustang

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...