Valve Adjustment Struggle

[focodave]

Charlie,
I feel your pain.
Really I do.
My engine just seized up tighter than a drum and it had what sounds like identical symptoms to your engine's.
I, too, didn't know what amount of noise was normal for these engines.
I adjusted the valves. The valve-train was dead silent afterward.
The noise still persisted.
I've rebuilt several muscle-car V-8's in my day and they have all been bulletproof for many many miles, so I know what I am doing when it comes to bearing clearances, cleanliness, etc.
I suspected I had a horrible piston-pin problem or severe piston slap due to a worn cylinder.
It almost sounded like a rod knock, but I didn't want to believe that.
I continued to drive it because the noise only really occurred when the engine was warm and under heavy load (and around 2500 RPM), so I drove it "gently" for about 500 miles after the noise began and she finally seized up on me this past weekend in the middle of a horribly busy intersection.
I haven't torn the engine down to see what caused it yet, and I don't want to scare you.
I am just sharing what may be a pertinent story.
Bottom line is that if it doesn't sound right, it probably isn't right.
I'm dropping a completely rebuilt engine in mine in the next couple of months and it is going to cost me some serious $$, but that's what I get for pushing my engine when I should have torn it down earlier.
Dave

[georgeramos]

there id definitely a distinct "chatter" that starts almost exactly 13 seconds into your video. I cannot say personally but would suspect that someone has had this happen before...

[blurple124]

George: I'm glad you can hear it, too - That means I'm not completely bonkers.

Dave: I know you weren't trying to scare me, but it's too late... On the other hand I'm glad you mention this. Are you planning on looking into the seized engine to find the culprit? If so, I would really appreciate you letting me know what you find. I'm at a loss for this diagnosis, and would rather not do an engine tear-down. Granted, that would be far better than having to put in a new one.

Stay in touch, and thanks for the info!

[SpecialTool]

Just a thought, but how about poking around with a mechanic's stethoscope to pinpoint the exact area of the noise. Watch out for moving parts!

[focodave]

George: I'm glad you can hear it, too - That means I'm not completely bonkers.

Dave: I know you weren't trying to scare me, but it's too late... On the other hand I'm glad you mention this. Are you planning on looking into the seized engine to find the culprit? If so, I would really appreciate you letting me know what you find. I'm at a loss for this diagnosis, and would rather not do an engine tear-down. Granted, that would be far better than having to put in a new one.

Stay in touch, and thanks for the info!

Here's what I found (see photos below)
It was the #2 rod bearing.
Not pretty!!

[blurple124]

Um.... how do I choose the right face for this one? or maybe this?

That scares me a lot. Did yours sound like it was coming from the valve train at first? Is there a test that I can run to determine whether it is a rod bearing or not?

[focodave]

Charlie,
I know that most of us want quick, easy answers to most things.
My answer is probably longer than you want to hear, but here it goes:
At first, I thought the noise was my valve train because I have read lots of things about these engines getting "noisy" in the top end (especially on high-mileage cars) and requiring occasional valve lash adjustments to keep them quiet.
I guess part of me wanted this noise to be as simple as too large of a valve lash.
My engine has 120K miles on it and the car has had a few previous unknown owners before me.
Coupled with the fact that my Fiat 4-banger is the only Fiat I've ever really been able to listen to up close, I did not have a reference for what is a quiet Fiat 2 litre and what was a noisy Fiat 2 litre.
The funny thing is that, in the back of my mind, this noise sounded like something more major. I thought, perhaps, that it could have been a worn piston-pin bushing or even severe piston slap in the cylinder, and in the very back of my mind I thought it sounded like a rod bearing -- but I did not want to believe that.
I adjusted my valves and they sounded very quiet afterward, but I still got the knock at about 2500 RPM and only after the engine warmed up. Also, the noise only happened when the engine was under a heavy load or being revved from idle to, say, 2 or 3 thousand RPM.
So then I knew, in the back of my mind, that I had to think about tearing this engine down to find out what was going on.
But I desperately wanted to drive my car this Spring, so I decided to "baby" the engine with the hopes that I could drive it for quite a while without any problems.
Well -- you can see the result of that in the photos above. The engine seized up tighter than a drum while I was in the middle of a very congested intersection!
How can you test for a bad rod bearing?
It's not easy. You can possibly get an indication from oil pressure readings, but you would have had to know the oil pressure when the engine was "good" to be able to have a baseline to compare the pressure to now.
Rod knock is a pretty recognizable sound. It is going to be a fairly loud knock that sounds like it is coming from the bottom of the engine (I guess that would seem obvious) but it is difficult to know for sure unless you do some major disassembly of the engine to check it out.
And who can define "loud"?
From what I have read, these engines do seem to make some noise even when they are in really good shape.
It's pretty tough to convey what "loud" is or isn't on a message board discussion.
What I know is this -- I have enough engine rebuilding experience that when I heard the noise in my engine, I knew in the back of my mind that I had a serious problem. I just didn't want to believe it.
Again -- don't want to scare you but if you have been around engines all of your life like me, and you hear something that sounds pretty serious -- you can bet that it is probably serious, if you have checked all of the easy things and they seem OK.
Dave

[BEEK]

focodave,

what i see when i look at your pictures is: the oil pan was damages and the pump had been broken. the car was driven for some time with a broken pump. this began the bearing damage. someone replaced the pump, you can see by the fact the oil pump does not have the oil stains as the inside of the block. then oil pressure was back to normal, but the damage had already happened.

what i also see is one of the worst spun bearings i have seen, the bearing was totaly gone from the bottom side as the crankshaft was running directly on the rod cap.

good news is a crankshaft, new bearings and a rod will fix the problem.

[wizard124]

Beek:

Nice detective work! Thanks for sharing your insights with us hobbiest types.

[focodave]

Ha!
Agreed.
Good detective work, Beek.
I looked at the oil pump closer and discovered "2L" written on it in black magic marker, appearing as a marking someone other than a factory person in Italy would have written on it.
With the oil pump looking new(er) than the rest of the motor, I think you nailed the history of this motor.
The P.O. must have gotten this all "fixed" just before he decided to sell it to me!
Oh, well -- I am glad it happened as I am now going to put a fresh motor in the car and go from there.
I'll probably be even more proud of it now, since I am becoming very intimate with it.
This, in my mind, is all part of buying a 30-year old car who's history I know nothing about.

Charlie, it looks like your thread was on the verge of getting hi-jacked here, so back to you.

I certainly hope this (spun bearing) isn't what you are going to be dealing with...

Dave

[md88plt]

That Valve Adjustment Tool video is assome except I would add card board. Use the card behind the tool against the cam bx so that the tool stays in place as you rotate the cam. Otherwise, in my expierience the the tool slides just enough so that you cant get the shim out. Just my 2 cents.

[blurple124]

Well I certainly appreciate the long response. The more information I have to address this issue the better.

I adjusted my valves and they sounded very quiet afterward, but I still got the knock at about 2500 RPM and only after the engine warmed up. Also, the noise only happened when the engine was under a heavy load or being revved from idle to, say, 2 or 3 thousand RPM.

The way you describe your sound doesn't quite match what I am hearing. I am no mechanic and I have very little experience listening to engine noises, so I don't think this is grounds to rule anything out. The noise I hear is the chatter heard in my video, which doesn't seem like a knocking to me. This noise grows louder as the engine warms up to temperature, at which point in increases with engine speed (which makes sense). Once the engine is warm, the noise is there from idle and does not seem to be affected by engine load. It is a pretty consistent noise with out thumping or knocking like you seem to describe.

I will poke around with a mechanic's stethoscope when I get back home and have the chance to. Hopefully my description above will help others decipher the problem at hand.



Thanks to all!

[KidDingo]

Hey Blurple,

Just wondering if you figured out the noise issue? I have a similar sound and am thinking its the no. 4 exhaust valve. Before I start running around gearing up for a valve adjustment, I wanted to see what others have found and done to remedy the situation.

[RoyBatty]

If you are able to verify in fact that you have valve clatter and the cold clearances are not loose.
Then pull the cam covers and measure the valve clearances with the engine warmed up for a comparison.
As I stated on the first page of this thread. You may need to install a different cam tower.

[blurple124]

I never did resolve the issue, although I have not had any issues with the car's engine performance.

The idea of checking clearances while warm is a good idea. I will have to do that when I get a chance.