Belt Skipped a Few Teeth

[18Fiatsandcounting]

Sorry this is causing so much grief... So I assume it's the crankshaft that appears to be hitting something, and not the camshafts?

To answer your question: If the belt is off by 1 or 2 teeth, it won't cause the rotation problem you're experiencing. It might not run very well, but there shouldn't be an interference problem. Now, if you're off by 5 or 10 teeth, that's a different story.

Before you pull the head, I'd try taking out the spark plugs and shining a strong light down the hole. If you see a valve laying on top of the piston, that's not an ideal situation. Perhaps you can see what's going on through one of the four plug holes?

-Bryan

[CharlieB]

Hahaha, no not ideal but...

I have a cheap boroscope that I finally have a use for.
This is the #4 cylinder.
Is that what I think it is?

[18Fiatsandcounting]

Gulp... That looks to me like a valve, with 3 issues: 1) it should be aligned with the indentations in the pistons (and it's not), 2) it should have a visable area around the seat where it seats (and it does not), and 3) it shouldn't stick that far out into the combustion chamber (and it does).

At this point, it looks like a valve head broke loose and is wandering around inside your #4 combustion chamber, desperately trying to find its way home and crying out, "Charlie, help me...." in a very small voice.

I hate to say it Charlie, but you've got some really wrong with that cylinder head and valves... I'm thinking maybe you're right: It's time to pull the head off that bad boy and see what's going on. Doesn't look right to me.

-Bryan

[CharlieB]

That should be my new avatar photo.
I started soaking the head bolts, etc... in pb blaster last night. I'll spray them again this afternoon and tonight just to be on the safe side. That worked well the last time I took the head off. I guess it's too early to order parts, correct?
Thanks Bryan

[18Fiatsandcounting]

I looked at the picture again just now in the light of day, and that's exactly what it is: a valve head, laying upside down on top of the piston, with a piece of the valve stem laying off to the left. My guess is that we have found your problem...!

Well, if it's any consolation, this might not be the end of the world. On my '69 many years ago, I had a galling issue with some new valve guides, and they "welded" themselves to the valve stem about a month after I had the new guides put in. In my case, this happened at 6000 rpm, and I ended up with 4 bent valves and a broken one like you have. But, new guides all around, all new valves, and a valve job on the head and I was back in business. The car runs fine to this day, 30 years later.

Yes, I would hold off on parts. Probably you'll need exactly the parts I mentioned above, plus gaskets and such, but this all depends on the condition of the combustion chamber inside the head. The top of the piston looks OK from what I can see, and of course you'll need to inspect the walls of the cylinder bore.

-Bryan

[CharlieB]

Thanks Bryan,
I hope to get start pulling the head tonight. I'll share some photos of the culprit(s).

[CharlieB]

Ok I got the head off and here is what I found.

I removed the end of the broken valve that was on top of the piston. It left a small indentation on the piston.

Here is the spring at the broken valve, itis stuck in a much higher position than normal.

Here is the broken valve from the bottom of the head.
Sooo, first question is how should I go about removing the broken valve?
I have not cleaned anything up, except I wiped down the top of the piston where the valve broke. There seems to be a lot of carbon (see the other piston in the photo). Is that normal?
I know it's hard to tell much from these pics, but I can take more. I wasn't sure what else I needed to show.
Thanks for taking the time to help with this.
Charlie

[18Fiatsandcounting]

Well, I have to admit, it doesn't look as bad as I had feared. Yes, you have a dimple in the top of your piston, but my guess is that you can just live with this. I can't see the whole combustion chamber part of the cylinder head, but from what I can see, it doesn't look too bad. Answers to your questions:

1. The easiest way to remove the remaining valve is to take it to a shop and have them do it. If you have a valve spring compressor, you might be able to do it yourself. Place the broken valve head on the valve seat and hold it in place with duct tape or the like. Then, using the valve tool, compress the springs until you can remove the 2 retainer collets at the end of the valve stem. Once those are out, release the tool and the valve shaft should slide out in the direction of the combustion chamber.

2. As for carbon buildup, yes, it is normal. Some spirited driving for several hours can often fix this, known as the "Italian tuneup". With the engine under load at 5000 rpm for a few hours, a lot of that buildup will slowly disappear. Your buildup does look a bit oily, so it might also be time for an engine rebuild. That's up to you. But, you will probably be fine with a new valve, possibly a new valve seat, and possibly a new valve guide. And a new head gasket, etc.

PS: Don't let antifreeze sit too long in the cylinder bores. It will rust the sides of the bore.

-Bryan

[CharlieB]

Well that doesn't sound so bad. I'll just have a shop remove the broken valve and install the new valve.
So can I get away with just replacing the broken valve, the valve seat and guide and head gasket and other gaskets?
I don't think a complete rebuild is in the budget for now.
Will the overextended spring at the broken valve need to be replaced? Or will it spring back to it's normal length when the valve is removed?
I'm glad you mentioned the antifreeze on the piston, I'll take care of that.
Thanks again Bryan,
Charlie

[aj81spider]

It's over extended because there's no valve to push against. Normally the valve head would be pressed against the seat and the spring would be partially compressed holding that tight. Your valve head is gone so the spring can extend much further than normal.

I'm with 18Fiats - this looks very fixable and you can probably do it yourself.

You can probably remove what remains of the valve yourself (although a shop is also an option if you're not comfortable with that). You might not even need a valve spring compressor (although they are cheap on Amazon). Unless there's a burr holding the valve shaft in it might just pop out the other side with a little push. If there is something holding the shaft in the compressor is easy to use and will give you access to the retainers.

[CharlieB]

Thanks AJ, that makes sense. I have a compressor tool somewhere, may as well try it myself.
Thanks again
Charlie

[18Fiatsandcounting]

If you have a valve spring compressor, give it a try. For the lever type compressors, normally they push against the valve head and the retainer collar at the top of the springs. Since you don't have a valve head in place anymore, that's why I suggested putting in the broken valve head temporarily, just to give something for the tool to push against.

Valve guides are surprisingly durable, so you might just need a new valve and perhaps some valve grinding (lapping) compound to grind a better valve seat surface.

As AJ noted, your springs are probably fine. Remember that there are 2 springs for each valve. Also, don't put your face directly in line with the compressed spring(s), because if they let loose, they could do some personal damage. Always point them away from you when removing.

-Bryan

[CharlieB]

This is the type of tool that I have, as soon as I can find it I'll give it a shot.

Thanks guys
Charlie

[CharlieB]

Ok I found my tool but I can't get the broken valve out. I crank it down and nothing happens. Taping the end of valve on the bottom of the head is impossible, unless I totally misunderstood what you meant Bryan. Any other options besides taking it to a shop?

[aj81spider]

That tool hooks on the spring coils then when you screw it down it supposedly pushes the top down. I was a novice, but could never get that kind to work either. I used one like this - which is the kind Bryan is talking about when he says to tape the valve head back in the seat so it has something to push against.

https://www.amazon.com/Spring-Compresso ... 178&sr=8-8