I think my 304 is sick

[spikey]

Well i worked late yesterday, got home and it was 92° so i pussed out and just chilled in the ac for the night.

I've been thinking and am still going to start my search with the timing cover but don't have my hopes up that it is the cause. Going through the parts i got with the jeep there is another msd distributor. I talked to the po and he said he was trying to get the ticking to go away. So I'll pull the dist. And see if there are any broken teeth as well.

I'll pick up a stethoscope tonight on my way home. I just know that the damn noise will be gone. Lol I'm sure i can get it to come back though..

When i had the valve covers off i did grab and wiggle each spring and rod. I have a 360 torn apart sitting in the garage so if nothing else shows my anything I'll cut up the covers like you said and check things out.

I appreciate all the input
Thanx

Spike

 

[jasonmark1993]

Ive never found a ticking distributor before.

I would start at the valve train and if that is not it, you can pull the tcover. If it isnt the tchain, you'll have to button it back up if you want to hear it run again.

 

[spikey]

Ive never found a ticking distributor before.

I would start at the valve train and if that is not it, you can pull the tcover. If it isnt the tchain, you'll have to button it back up if you want to hear it run again.

Ok I took your advice as with others that said not to jump straight to the timing chain. I picked up a stethoscope on my way home and fired her up. That ticking I thought was coming from the distributor was coming from the back of the motor. I could hear it at the dist. but it was much louder from under the fourth spark plug back on the drivers side. I just changed plugs, and wires plus that tick was there when I bought the Jeep. So any thoughts on what direction I should go next?

Oh here is a video of the ticking. I kept trying to rev it enough to get the slapping noise back while I had the scope out but it didn't want to come back yet so I haven't chased it down

Tick tick tick - YouTube

 

[jasonmark1993]

Is that video after the other one??

That almost sounds like an exhaust leak right there, which can cause some weird problems if its right at the head. It can also sound metallic; mostly when they are at the rear of the engine near the firewall.

The stethoscope can be used with the metal end (held against the engine at different spots) or just the plastic tube. I actually like using the plastic tube portion better as noise travels so much through the metal.

Not sure what that thing has for emissions. Is their an air pump run by a belt or a metal tube running across the engine at the back between the heads? Work the stethoscope with the plastic tube around the EGR valve also.

 

[dauntless89]

I agree with the exhaust leak. That sounds like the most likely problem at this point for the ticking.

 

[spikey]

Cool that's at least not really bad news. I couldn't get it to make the bad noise today though. I'll have to try tomorrow.
Yea the second video is from today.
I'm not going to tear anything apart till i chase down the location of the other noise. I can chase down the exhaust leak while trying to make it knock.

Wouldn't it be almost as easy to take the parts off the AMC 304 and put them on the 360 i have in the garage.. Lol

Once again thanx for the input I'll post up when i find where the knock is coming from

Spike

 

[mtnwhlr]

Yes but what about the backfiring and loss of power? It would cause that.

 

[spikey]

The timing? Or something else? I'm not driving it right now anyway so have no objection to opening up the cover. I just hate when I'm on a forum helping someone and they don't listen so I'm trying to go through the different steps to chase it down rather than just tear it apart.
I was told that the guy i got it from could warranty the timing chain so it really couldn't hurt to look.

Spike

 

[GatorBate]

What about running a compression check? if you have bad intake valves that aren't sealing completely that could cause backfiring.

check your spark plugs any loose ones?

 

[jasonmark1993]

Exhaust leaks at the head can cause backfiring, loss of power. Its weird but Ive seen it lots of times.

Maybe you have some weird situation where the exhaust gasket is fluttering around inside the header? Id be reluctant to do header gaskets if I thought I might have a serious valvetrain or other engine problem though since you dont want to do it twice. I noticed a weird looking spot on one of the headpipes; its not cracked is it?

Try the scope without the metal part; you'll probably narrow it down.

 

[spikey]

I did a compression test last week. Keep forgetting to mention that. All but one were between 117-120. One was at 105. I know that's not great but still within 15% of the others.

Lol that spot on the header was me being a dumass. After i put in the new plug wires i noticed a couple resting on the headers so i used zip ties to get them away, just didn't cut the ties back so one melted.

After work tonight I'll taker it for a drive and try to get the knocking back
Spike

 

[JR74CJ5]

The first video sounds extremely like a collapsed lifter... Sometimes they are hard to diagnose, and I have seen them collapse under heavy acceleration then return to "normal" Later. (My old Ford 351M)

It's a big job, but I would pull, inspect and clean or replace them all. and while you have them out, the push rods may show a slight bend or dis-figuration otherwise unable to be seen while installed.

When is the last time the oil was changed?

If your oil has either:

• Gotten gummed up with crud, and is temporarily clogging lifters
• not been changed for so long, it's bypassed the filter and again above.
• (worst case) gotten a hold of metal from somewhere and it's flowing through some areas (not as likely)

You can be intermittently clogging multiple lifters making the noise change from one position to the other and valves not operating correctly can be causing all of the symptoms you're describing.

Even if the oil is fine, you still could be experiencing this problem, but it would surprise me more.

The second video, I would agree with all others and assume 99% sure it is a exhaust leak... I, unfortunate, have become quite familiar with that particular sound.

Let some others comment after this, and let you know if I may be way off base or if there is an easier way to tell than just "diving in" to removing them and replacing / soaking and cleaning. And oil change never hurts, unless it has JUST been done, or you have to tear the engine apart immediately after...



~ JR

 

[JR74CJ5]

I did a compression test last week. Keep forgetting to mention that. All but one were between 117-120. One was at 105. I know that's not great but still within 15% of the others.

I know you just did this, and all would suggest the lifters are obviously working, however the noise was not present at time of testing correct?


~ JR

 

[dauntless89]

the collapsed lifter theory would fit well, except for the part where the ignition timing changed. that's what's stumping me at the moment.

 

[JR74CJ5]

the collapsed lifter theory would fit well, except for the part where the ignition timing changed. that's what's stumping me at the moment.

I thought of that... My theory (and its far stretched) is that the timing chain is not actually the issue and the distributor is just moving a little (either not held down tight enough) OR the timing chain is the issue, and its not actually jumping a tooth, but stretched some, so the timing is different each time it's checked?

So my theory is it's possible these two are unrelated, though it appears they co-exist with each other...


~ JR

 

[spikey]

Well i guess if it helps any I've always been a little off in the head. My jeep and i seem to be a good team and are a little alike...

So what direction should i go after work today? Do i try and force it to knock? Take off cover and look at timing chain to at least eliminate it if nothing else?
Oh yea, i change the oil every 3 1/2 months. So it'll be due in two weeks.

As of right now all i really know about motors is that when i blew one up in old cherokee i took it apart piece by piece to see how everything goes together. So don't laugh too hard here but if it is a valve would i find metal in any fluids? Like if i drop the oil pan or anything?

Spike

 

[JR74CJ5]

So don't laugh too hard here but if it is a valve would i find metal in any fluids? Like if i drop the oil pan or anything?

I doubt it. But not sure But if you have a broken valve it WOULD show up on a compression check...

I am not sure about my diagnosis... so it's up to you bud It's just what jumped at me when reading through everything and listening to that first video... Taking off all the rockers and pulling the rods and lifters is not the simplest and least time consuming of jobs, but neither is removing timing cover...


~ JR

 

[spikey]

Ok I started my journey with the timing cover. Mainly because of the backfiring and the timing slipping.

Timing chain - YouTube

Of course I made another video. It just helps things out..

I searched a little and found out that the tolerance is supposed to be 3/4" of slack and I measured the way my Hayes said to and ended up with 1" of slack.

I'm not sure why a double roller would stretch so fast though. The guy I got the Jeep from can warranty it for me so that's good news but could I have another issue?

 

[tarry99]

Ok I started my journey with the timing cover. Mainly because of the backfiring and the timing slipping.

Timing chain - YouTube

Of course I made another video. It just helps things out..

I searched a little and found out that the tolerance is supposed to be 3/4" of slack and I measured the way my Hayes said to and ended up with 1" of slack.

I'm not sure why a double roller would stretch so fast though. The guy I got the Jeep from can warranty it for me so that's good news but could I have another issue?

Spikey:

Roll the motor up on Top Dead Center on #1 Cylinder by taking all your plugs out and put your finger in the spark plug hole and slowly turn the motor over till the compression stroke pushes your finger off...........that's close to TDC on #1 you can also look in the hole with a light and rotate the crank either up or down till the piston is at the highest point.............. Check your timing marks at the vibration dampner and the mark on the front cover..........then pull the Dist. cap and check where the rotor is as compared to # 1 position ...........I'll bet its off a tooth on your timing chain.

 

[spikey]

Tarry99 thanks for the help but i already had her torn down before you posted.

Just a little update. i did find some aluminum shavings in the timing cover and the little lip above the crank was worn down a little. I still haven't found the tolerance for the edelbrock chain but my fsm says 7/8" is max deflection in the chain i had 1". The new chain is literally just a hair shorter so I'm keeping my fingers crossed but doubt this was the real problem.

I would have had it back together yesterday but wifey decided to fall through the ceiling from the attic so i had to put things away and take care of her. I'll post up if the knocking/ slapping comes back. Otherwise thank you all for the help

Spike