I think I found my ticking noise....

For those who haven't seen my recent threads on the aftermath of a timing belt failure, I put a new timing belt kit, and a new head on my engine.

The exhaust valves had hit the pistons when the belt failed, but the intake valves did not leave a mark at all.

Well, I took my new head off again today, and now there are signs that the intake valves have been hitting! I'm not sure how this is possible. The timing belt was installed correctly, with the proper lock tools. Torsion value was adjusted with VCDS to achieve 0.0 degrees. (It was a valid reading, because I was finely adjusting it between -1.0 and 1.0, so it's not way off and reading 0).

The head gasket is a 3 hole gasket, because that's what the car came with from the factory. I measured piston protrusion and that was all normal. In fact, based on my readings I theoretically could have used the thinner two hole gasket.

So I'm not sure why the intake valves were lightly hitting the pistons, but they were.

My theory is that maybe the piston wrist pin bushings were very slightly damaged during the previous timing belt failure, and so the pistons are exceeding their normal travel and are slapping the valves. I'm really not sure what else it could be, unless the cam is not made right or something! Examining the pistons and trying to find unwanted movement at the wrist pin doesn't reveal much. If that's the problem, it's very difficult to tell.

Well, I have used pistons in excellent condition ready to go in, but I'm kind of taking a step back to figure out why the valves might have been hitting. I'm not sure what else I can do, other than time the cam properly, and install the proper head gasket based on the piston protrusions.

The connecting rod bearings and the journals on the crank look perfect, so I don't think connecting rod bearings could have anything to do with this.

If things get too stupid I'll be looking for a 2015 Golf TDI...

Valve timing would have to be way, way off for the intakes to make contact. They start to open when the pistons are on their way down from tdc so there is no "normal" chance for contact like exhaust valves which are open on an up stroke.

jettawreck said:

Valve timing would have to be way, way off for the intakes to make contact. They start to open when the pistons are on their way down from tdc so there is no "normal" chance for contact like exhaust valves which are open on an up stroke.

Click to expand...

That's what has me confused. The timing is definitely perfect. At no time was it ever put together wrong and operated that way.

I'm going to have a better look at the head. Maybe the intake valves are not sitting completely flush with the head when they're closed. They should be, right? When the piston is at TDC, there's basically no room for anything to be sticking down below the surface of the head, if I'm not mistaken.

One (outside possibility): oil pump pressure relief valve is jammed, causing high oil pressure, which will cause the hydraulic lifters to over-extend and thus valves meet pistons. Oil pressure gauge reading at operating temperature is the usual diagnostic.

Rare, but possible, and still a bit hard to explain only the intakes being affected.

It's really either that or the crank/cam timing is wrong, despite everything that's telling you otherwise. For sure with the crank locked at TDC both lobes of #1 are pointing up?

Once you've eliminated the obvious it's time to speculate on the unlikely.

Well, mystery solved. I looked at the new AMC head and my old head.

The intake valves on the AMC head actually protrude slightly when they are closed. I mean, it's not just a few thousands, it's an obvious amount, like a millimeter, give or take. The exhaust valves sit flush.

On my old head, the valves are actually slightly recessed when closed.

This explains why there was no damage to the lifters on the AMC head. I replaced them once, thinking they might be the problem, and the ones I took out were fine. The pistons were hitting the valves when they were closed, so the lifters would be unaffected.

Maybe AMC does not realize that North American BEW engines have no valve reliefs cut in the pistons, unlike most European versions.

What a $hit$show.

So, I guess what I can do at this point is take the exhaust valves from the new head and put them in my old head. The intake valves on the old head are fine as they didn't hit when the timing belt slipped, only the exhaust valves did.

Another good reason to have Franko6 rebuild an existing head whenever possible, I guess.

That's what what I was wondering, why not replace valves in the original instead of taking a chance on an aftermarket unknown.


I am not sure I would trust the exhaust valves from the AMC head, or at the very least measure the stem length and dress them down if needed.

EEK!

If the aftermarket guys got THIS wrong what else did they get wrong?

Careful here....

If it’s new, what’s the warrantee period on that AMC head? I’d be giving them a call to see about a replacement, and tell them what the error is in their design.

KyleMillione said:

If it’s new, what’s the warrantee period on that AMC head? I’d be giving them a call to see about a replacement, and tell them what the error is in their design.

Click to expand...

Or certainly in their execution.

KyleMillione said:

If it’s new, what’s the warrantee period on that AMC head? I’d be giving them a call to see about a replacement, and tell them what the error is in their design.

Click to expand...

At this point I just want to get the thing running and be done with it.

I’m going to take the lifters, cam, cam bearings, valve stem seals, and probably the exhaust valves from the new head, and put them in my old head.

The old head actually didn’t sustain much damage and what I should have done in the first place was just replace those parts. I thought a whole new head was going to be easier.

I’ve just finished putting new main bearings in, which actually was a waste of time because the old ones were fine. I’m about to put different pistons in too, along with new bearings and rings. Again, a waste of time. It’s all in the name of TDI fun.

At least look at the intake lifters and valves very closely.
They don't respond well to mechanical compression.
And make sure the lifter bores in the old head are OK.

Well I’ve got the bottom end rebuilt. I managed to concoct a great way to protect the oil squirters and crank while honing the cylinders. I took a piece of stiff foam packing material, about an inch and a half thick, cut it into a very snug fitting circle, also put a plastic circle made from a Kozy Shack pudding lid on one side to protect it, and poked a hole in the middle with a looped zip tie though a washer to help pull this contraption out of the cylinder. I cut a notch halfway though where the oil squirter goes.

With this thing in place, I could hone away like a madman. When finished, I just grab the loop in the middle and pull it out, along with all the debris. Then I give the cylinder a wipe with a clean cloth.

After all the honing was done, I sprayed it all down with brake cleaner, followed by WD40, and then a little oil in the bores for installing the pistons.

The pistons all went in beautifully. The crank spins without any unusual resistance. It feels very much like it did with the old pistons in place before I started. I’m using Liqui Moly assembly paste.

Piston protrusions measured between 0.038 and 0.042, so only 0.004” between them. That should be okay for a two-hole head gasket, right?

I’m not sure what’s normal, but I measured the length of my exhaust valves and found that they are between 88.28mm and 88.33mm.

I have taken one out of the AMC head so far and it has a length of 88.91mm, making it about 0.6mm longer. They have a part number of 3504-LAF on them. I suspect they are probably not made by AMC. They likely just get them from a supplier and install them, same as if I bought an aftermarket valve from a vendor. Therefore, I might as well use them.

I think I’ll save myself the aggravation of swapping valve guides, as there doesn’t seem to be much difference between the new and old ones anyway.

Personally I would not use anything from the AMC head or the old one.
You are doing a lot of work. Don't take shortcuts.

Maybe call Franko6 and discuss what you are planning.
See if he has any knowledge about the AMC heads.

Your trying things I use to do before I learned not to.

^^^ Same here. I would not risk any of the AMC parts on your "old" head, and I agree contacting Frank is the thing to do. Why take a chance on having to tear into the motor as soon as you light the engine up?

All the exhaust valves from the AMC head were exactly the same length, to 1/100th of a millimeter. My old valves, which had hit pistons, were of varying lengths.

So I'm more comfortable with the ones that haven't hit anything. They were already working fine on my car with the AMC head, and I would have kept using them too, if it wasn't for the annoying ticking noise which lead me to take the engine apart. The pistons hitting the protruding intake valves was the ticking problem. Exhaust valves were unaffected.

At this point I'm waiting for a head gasket, head bolts, cam cap bolts, injector seals, etc to arrive in the mail. Once I have those, nothing will stand in my way!

Mike_04GolfTDI said:

I’m not sure what’s normal, but I measured the length of my exhaust valves and found that they are between 88.28mm and 88.33mm.

I have taken one out of the AMC head so far and it has a length of 88.91mm, making it about 0.6mm longer. They have a part number of 3504-LAF on them. I suspect they are probably not made by AMC. They likely just get them from a supplier and install them, same as if I bought an aftermarket valve from a vendor. Therefore, I might as well use them.

I think I’ll save myself the aggravation of swapping valve guides, as there doesn’t seem to be much difference between the new and old ones anyway.

Click to expand...

Somehow, down the road (perhaps even far down the road) I think perhaps this isn't going to play out all that well. Hope I'm wrong as usual.

jettawreck said:

Somehow, down the road (perhaps even far down the road) I think perhaps this isn't going to play out all that well. Hope I'm wrong as usual.

Click to expand...

Hate to say it but me to.

Today, since I’m still waiting for parts, I took out my intake valves and cleaned 14 years worth of EGR crud out of the head, and off of the valves. I don’t think it will make a noticeable difference, but it’s better than leaving it to break off and jam a valve open some day.

I should have it running next weekend.

jettawreck said:

Somehow, down the road (perhaps even far down the road) I think perhaps this isn't going to play out all that well. Hope I'm wrong as usual.

Click to expand...

I couldn't have said it better myself. I would fix the original head with new quality parts, or have someone competent do it (Frank06). I would package up the AMC head and send it back to them.

pdq import repair said:

I couldn't have said it better myself. I would fix the original head with new quality parts, or have someone competent do it (Frank06). I would package up the AMC head and send it back to them.

Click to expand...

The only things I'm using from the AMC head are the exhaust valves, lifters, and the cam.

Since I can replace the cam myself in under four hours, I'm not afraid to use the inferior cam at least until it starts to wear out. It would be a shame to toss it in the garbage without at least using it for a while. When it wears out, I"ll just buy a cam from Frank and put that in.

The exhaust valves that I'm using have never struck any pistons, so there should be nothing wrong with them.

The lifters are INA black nitrided lifters. I don't think you can get better ones than that.

I'm not expecting any catastrophic problems.

Edit: I found who makes the valves. Looks like a company called Tecnilaf (http://tecnilaf.es/en/tecnilaf.html).

It seems they make valves for just about everything. Here's their catalog: http://tecnilaf.es/catalogo.pdf (Large PDF)

I see no reason to suspect there would be anything inherently wrong with their valves. They've been making them for a long time, and they are on OEM supplier, so any new car you buy might have their valves in it.

My/our reservations aren't with the "parts". It's with putting them back in a head that had an "event" and hasn't been expertly inspected and checked out/refurbished.
Carry on.

jettawreck said:

My/our reservations aren't with the "parts". It's with putting them back in a head that had an "event" and hasn't been expertly inspected and checked out/refurbished.
Carry on.

Click to expand...

Oh, I see. Well the head sustained no damage to the lifter bores, sealing surfaces, valve seats, or valve guides.

All that really happened was my timing belt slipped a few notches. The car still ran, but had an obvious lack of power.

Franko6 has seen pictures of it and he said he normally wouldn't even remove a head like this. Just put new lifters and a cam in it and it should be fine. What I'm doing is probably overkill. If I had listened to him in the first place, and just done that instead of replacing the whole head, I would have saved myself a lot of trouble, I'm sure. Some people just need to learn the hard way...heheh

It’s running perfectly! Now for a little break-in drive.

Edit: I drove around for about 10km and it seems fine!