What's up with this valve?

So I'm breaking down the head on my ALH to bring it to the shop for cleaning/checking. Removing all the valves to do this. One valve would not come out as easily as the others. All the others I was able to remove by hand but this one I had to press out and with it came shavings of metal on the grooves for the keepers. This valve will not insert into any of the locations so clearly there is something wrong with it. I'm sure now that guide is destroyed which isn't a huge problem because I was planning all new seals/guides anyway.

My question is, what is up with this valve? Clearly I need a new one but why? This valve also was the dirtiest if that makes a difference. Should I do all the valves or just this one? This motor only has 140k on it. To compress the springs I used one of the C clamp style valve spring compressors.

Advice? Opinions?

If your going with new guides, you should get new valves. go with the undercut valves from ID parts, when i ordered mine, it was just standard OEM but when i got them, they had undercuts on them. They are not that expensive and your going to have new wear on them and seeing as you need one, your going to pay shipping anyways.
that valve was definalty bent or mared bad. Make sure you add some zink for the new lifters if you replace them. What is the valve play on them? side to side? mine was over 2 mm, YIKES!

The area where the keepers sit got mushroomed thru normal use, you would normally file it down if it won't come out but ramming it out ruins the guides. You just need one valve.

Buy OEM valves, we've had issues with aftermarket valves breaking. All the Vendors carry the ones you need.

OK, someone's got to ask...

WHY did you pull the head?

The other thing I've seen is that when the valve spring is released and one of the keepers is one notch too deep, it will put 2 little dings in the valve stem about 170 degrees apart from each other and make it very difficult to remove.

Turbovan - I have not seen mushrooming on VW valves before - maybe if there was a lot of valve float?

I'm wondering if there was a timing incident with the attendant piston hit.

Good question KLXD

Bolts-n-Hose - were any of the lifters spidered or cam lobes damaged? An answer to UhOh's question would be good...

On second thought I dunno that the OP's problem would be the result. Thin areas of the valve would mushroom. The keepers wouldn't see any extra load.

And only one valve? Intake from #2 or #23 cylinder? There's more to this story needing telling...

The offending valve is exhaust valve on Cyl 1. There is no visible damage at all to the cam or the lifters. No marks on piston or valve face. The resistance begins exactly at the keeper grooves. I pulled the head just to clean it and also to install ARP studs. I just got this motor and I am prepping it for a swap to my toyota 4runner. There is an intense amount of "crap" on the inside of the head. Me being me, I want it to be clean when I put it in and the only way to really get that done was to break it down. Plus, I have some time to kill before spring when I can swap the motor.

I'm sure I could have just left it and put the motor in, but I cant leave well enough alone. I'm sure y'all can relate

Ah, OK!

Yeah, sounds like you're probably fine just continuing on: do, however, check piston protrusion just to make sure.

Not sure that it's necessarily warranted, but Franko6 would be the guy to touch any head work that I'd need done. If the full history of this engine isn't known then it's possible that someone had valve contact at one point and didn't fully attend to all possible issues (lifters, and perhaps cam, could have been replaced, in which case traces of a previous event might now be hidden): it's possible that a valve stem is still waiting to break.

So I more thoroughly inspected the the valve. There is a definite lip at the top of the top keeper groove. Measures about 6 thousandths larger than the stem above it. You can feel it with your fingernail. It is not present on the other valves. Seems to be the mushrooming that turbovan is talking about?

What's that valve seat, cam lobe and lifter for that valve look like compared to the others?

Fix_Until_Broke said:

The other thing I've seen is that when the valve spring is released and one of the keepers is one notch too deep, it will put 2 little dings in the valve stem about 170 degrees apart from each other and make it very difficult to remove.

Turbovan - I have not seen mushrooming on VW valves before - maybe if there was a lot of valve float?

Click to expand...

Mushrooming is the wrong word but its hard to describe what I mean typing, lol. The keepers dig in creating a burr/lip, that would be a better way of describing it.

Bolts-n-Hose said:

So I more thoroughly inspected the the valve. There is a definite lip at the top of the top keeper groove. Measures about 6 thousandths larger than the stem above it. You can feel it with your fingernail. It is not present on the other valves. Seems to be the mushrooming that turbovan is talking about?

Click to expand...

Yep, that's it.

I've had some engines apart where some had it, none had it or most have it, so its nothing to worry about but I would replace it just to be safe.

Learn something new every day

turbovan or Bolts, could you post a picture of the offending area of a valve that has this?

Fix_Until_Broke said:

Learn something new every day

turbovan or Bolts, could you post a picture of the offending area of a valve that has this?

Click to expand...

I don't have any engines apart at the moment, so I have nothing, plus it would be hard to see in a pic.

It would be next to impossible to see in a picture. Cant even really see it in person. You can feel it though. I did a quick sketch of an exxageration, just so you get the point. This is how mine is. There is a flare right at the top groove. Good valve on left. Effed valve on right.

Interesting - Thanks for sketching that up!

Still trying to think of what would cause that to happen and be "normal"

If the lower keeper grooves were oversized then maybe that top groove was taking more stress? (maybe with a loose fitting keeper?) This with a little valve float (maybe some nudging from a piston top)? Wondering if it could have been a (crappy) replacement valve.

UhOh said:

This with a little valve float (maybe some nudging from a piston top)?

Click to expand...

I wondered that myself, but if the piston nudged the valve, the force would transmit to the bottom of the groove, not the top. The only way additional external force would cause this is if the valve were forced down, but the keepers "resisted" it. An overly strong valve spring or perhaps loosely fitting keepers would make more sense to me.

Bolts-n-Hose said:

I wondered that myself, but if the piston nudged the valve, the force would transmit to the bottom of the groove, not the top. The only way additional external force would cause this is if the valve were forced down, but the keepers "resisted" it. An overly strong valve spring or perhaps loosely fitting keepers would make more sense to me.

Click to expand...

Cam and lifter are also pushing down. Think about a nudge from the piston and then a force by the cam/lifter. I'd have to agree that this is a bit freakish. Maybe an initial marginal assembly that doomed this from the start (plus marginal parts). BUT... if others have seen this then maybe it's not all the freakish (and perhaps just parts on the edge of the statistical curve). For sure, this beats having a valve break off!

I dealt with the exact same thing this weekend when i oulled my head on a few valves

ghohouston said:

I dealt with the exact same thing this weekend when i oulled my head on a few valves

Click to expand...

So its at least semi common. Did you notice it and sand them before destroying the valve guide or did you push them through like a caveman like I did? lol

I would be cautious in saying,"Get your parts from here."(or from there...)as that is not assuring you necessarily get a good part. 'Undercut' valves... maybe on the exhaust, but I don't know a good one that is not. But I know plenty that are undercut that are CRAP. But this is just the same old story.

We expect that many vendors will sell more than one version of a part and quite honestly, we've had wholesalers change manufacturer to fill an order...with Chinese junk! When I say I want a particular valve, I don't want somebody deciding for me to send whatever stock happens to be on the shelf. In case you hadn't noticed, many vendors will not say the manufacturer, but only that they sell 'one of those'. So, you get what they decide to sell that week. We are more specific. It's a reputation thing, that it's not just assembly, but the parts you put in.

As for that one valve that came out hard, it can bend from the tip top to the tulip. Sometimes, it bends right below the keepers. Sometimes it warps the entire length of the stem. But it's damaged and the only way it damaged is piston contact. When it hits a piston, the 'tell' is that it wrecks a lifter. That is the way it works.

It is entirely possible to mushroom a valve stem. It doesn't happen often, but when it does, it's impressive. We have several valve stems that hammered so directly up and down, the stem created a bulge. The biggest mushrooming was and increase in .050" on the stem(very impressive!). That wrecked the head when the bulge was rammed into the valve guide, breaking the cylinder head's valve bore.

In a single head just last week we had three valve mushroomed, .008', .007' and .005".
The heads of two valves had to be cut off and the valve stem with guide were driven out as a unit to save the head.

In your case, the top of the valve seems to have gotten whacked hard. In that is only part of the story.

If your top ring land is bulged out like that, you have to remember, the top ring sits in a cast iron insert and there are gap limits for the ring land.. .0015"-.002". With your piston so abused, it's probably a problem that needs to be addressed. Like maybe change out the piston.

If you need any more detail, let me know.

Hi Frank. Thanks for chiming in here. I think it is possible that you misread my problem. The sketch above is of the keeper grooves in the top of the valve, not the piston/ring lands. The "lip" I show in the sketch measures about .006" (total) relative to the stem above it. When it was driven through the guide, it took a fine shaving of material with it.

In regards to the impact of the valve...Is it possible for pistons to hit valves and not leave any evidence? There are no marks on the valve or piston, and the lifter is pristine.

I appreciate your input, and I certainly want to have all the information before installing the motor.

Bolts-n-Hose said:

So I'm breaking down the head on my ALH to bring it to the shop for cleaning/checking. Removing all the valves to do this. One valve would not come out as easily as the others. All the others I was able to remove by hand but this one I had to press out and with it came shavings of metal on the grooves for the keepers. This valve will not insert into any of the locations so clearly there is something wrong with it. I'm sure now that guide is destroyed which isn't a huge problem because I was planning all new seals/guides anyway.
My question is, what is up with this valve? Clearly I need a new one but why? This valve also was the dirtiest if that makes a difference. Should I do all the valves or just this one? This motor only has 140k on it. To compress the springs I used one of the C clamp style valve spring compressors.
Advice? Opinions?

Click to expand...

Since you are going to send it to shop, why not send it to Franko6? Actually, he will send you a box, pack in there and send it to him.

Ah, now I see... it looked like piston grooves. The grooves in the valve stem are round, but I can see; it's just a rough illustration. That is abnormal wear. Usually the top of the stem will deform. Not at the keepers. It might have been sticking. The normal order is the valve hits a piston, the valve will bend. That is harder to determine if a valve is bent than it is to tell if a lifter is dented or cracked. But you cannot ruin a valve without also ruining a lifter. The lifter is much more obvious.

Since you asked in the PM... A basic reconditioning is $321, cleaned, valve job, new guides and seals, surfaced and valve stems cut for proper pre-load. Average head that has ruined cam and lifters is about $600-$650. We double the warranty from 1yr, unlimited miles to 2yrs, unlimited when all assembly parts are purchased with build. We generally recommend replacing at least the timing belt and the tensioner, but that is a judgement call if the whole kit should be replaced, by when the timing belt was last replaced and the quality of the parts.

Jokila, thank you very much for the positive feedback. What we do craftsmanship and done with pride... which is not common enough.

However, we do not send boxes. We send pre-paid, downloadable UPS shipping labels with packing instructions. Following instructions does help and the customer gets to take advantage of discounted shipping rates with our label.

Bolts-n-Hose, More than likely, we would replace only the one valve. We have a lot of people who think all the valves should be replaced, but replace them with poor quality valves. The OEM valves are VERY durable.

To give you an idea, several years ago, we received a cylinder head with 611,000 miles. The lifters were so worn, that they had stress fractures; what was still good. Two of the lifters had collapsed from wear and wrecked the cam and the valves under the lifters. When we got everything apart, the rest of the valves were in excellent shape. We touched them up and put them back in.

I asked the customer if they wanted to change out the rings, rod bearings and main bearings. He said, "Why?", and I responded it was well past maintenance interval.

He said, "How much longer will it last?" '

"Is it burning any oil?"

"No..."

So, we put it back together. It made it to 730,000 miles and got T-boned. That's got to be some sorta record... I wonder how far it could have gone.

Frank, isn't it valve seals/guides that are primarily responsible for oil consumption? How can one differentiate such that one would know to re-ring? Seems that only after one installs a reconditioned head would one know for sure.

Bolts-n-Hose said:

So its at least semi common. Did you notice it and sand them before destroying the valve guide or did you push them through like a caveman like I did? lol

Click to expand...

Caveman. Already had 1 broken valve guide on #2 exhaust, and that same valve stem seal was literally gone. I will either get a new head or rebuild this one with new guides and valves. Cheap enough to replace em all in the grand scheme of things

UhOh,

The reason our diesels have vacuum pumps is because the engine does not create any vacuum of it's own. Unlike a gasoline engine, the diesel has pressure induced intake valves, so instead of sucking oil down the intake guides like a gasoline engine will do, the diesel will not draw oil down the guides. Therefore, when there is excessive blow-by, it's usually rings first, and only slightly increased by the boost pressure that loose guides will produce.

You also have to consider that the cylinder pressures for a diesel are more than double that of a gasoline engine, and once again, any problem with rings will cause oil consumption. Excessive blow-by will eventually push oil through the CCV and oil up your air intake pipe to the turbo.

Which brings to the other major oil loss contributor; the turbo. Turbos will always lose some oil, but if you have a side mount intercooler and it has 1/2 cup+ of oil in it, that is a turbo ready to go runaway on you. If you pull the turbo to intercooler connection pipe off and oil runs down to your arm pit(fortunately that episode wasn't my armpit, so I got to laugh), it is primed and the hammer is pulled back...get ready to replace your turbo or bend some rods...

I never heard back from you ghohouston... Is that the way we will leave it? As for a valve guide that was punched out by a valve, that is dicey business. If it didn't crack the guide bore, we have oversized valve guides, as punching them out that way is really hard on the bore.

Bolts-n-Hose, Pushing a lightly damaged valve through a guide will work, but there is a point that we work the other direction. If the valve takes unreasonable force to go through the guide, it can split the valve guide bore. If that happens, throw your head away. There is no fixing that. If the valve appears to stop in the guide, we cut the head of the valve off and push the guide and stem out as a unit from the head gasket side. That is your better chance.