Hard knocking/ticking sound *Updated w/ pics*

[72Ladybug]

Hello all.

I'm new here and I'm finally breaking down to get some more advice on my situation. I purchased a 72 standard beetle in August from a pawn with a glimmer in my eye and excitement in my heart to finally own a "bug". I'm pretty mechanically inclined after years of working on a Yamaha VStar but I still have far to many gaps in knowledge to be comfortable moving forward.

The car came with quite a packet of work and purchase records. A rebuilt engine with just over 5000 miles on the odometer was put in in 2009. According to the previous owner, who I met in traffic one day, the odometer was not original and was put in shortly after the rebuild. The valves/timing and a carb rebuild were done only a month before I purchased it.

As everything seemed up to date and the engine sounded solid, I drove here for a week before I had some extra time to dig into the car. When I went ot do my oil change (no recent record), I decided to check the valves and found light rust on 3 of the 4 springs on cylinders 1/2. On the exhaust valve of cylinder 2. While the spring was broken, the whole spring was still held in place by the retainer and the valve was in spec.

https://www.thesamba.com/vw/gallery/pix/1732585.jpg

The engine was pulled and all springs on that side wee replaced and the valves and timing were set. The valve stem on the broken spring slide smoothly and solid. It didn't seem to have anymore play the the other valves. Cylinders 3/4 all had clean intact springs. The engine was put back in and I've been happily driving since September until I decided to fix some rusted sections in December. In the process of this, it was mentioned to me by another bug owner that the knocking/tapping he heard seemed to loud and appeared to be coming from the passenger side of the engine. I had always noticed a bit of tapping that was often louder when I first started it up but the valves were in spec. Additionally, it seemed to clear up a bit as the car warmed and she drove like a champ. This got me delving into engine sounds and trying to find similar issues. Over the last 2 weeks I've reset my valves with little to no change in sound. The car now has 6700 miles.

I have not done a compression check but the engine pulls strong from high to low rpm and through all gears. She also shifts cleanly with smooth clutch action. I have begun to notice the sound is most prominent when cold and while at idle. While warm and at idle, I can limit/stop the knocking/tapping by giving it a touch of gas.

I found this thread:

https://www.thesamba.com/vw/forum/viewtopic.php?t=512885&highlight=rocker+arm+advice+needed

It seems to match my situation which has me concerned I have a bit more work and a lighter wallet to look forward to. Reading through it reminded me I recall seeing one of my rockers that was offset from the valve stem and had some wear on the screw, when I had the engine out for springs. I will post pictures in the morning.

The sound after a cold start --> https://youtu.be/9ZAqh5DqTKs

Idling after a 15 minute drive --> https://youtu.be/9ZAqh5DqTKs

Thank you!

[72Ladybug]

Update

I rechecked the rockers and valves this morning. I found the intake valve adjusting screw on cylinder 1 was worn and not striking flush with the valve stem. The rest of the adjusting screws appeared flat and fairly centered on the valve stems. It is not nearly as bad as the link I previously posted.

[VW_Jimbo]

Welcome to the Samba and Volkswagens!!!

Sounds like you got the Baptism by fire routine, as is way too common in this hobby! Lots of different ideas and hands all converging onto one poor car!

Glad to see you found a solution! If I am remembering correctly, the valve adjustment screw is to strike the top of the valve stem, off center, so that the valve rotates around. From your description, it sounds like you have centered the adjustment screw. If that is the case, it may be worth looking into and verifying. Or maybe another more knowledgeable member will chime in on valve stem to adjustment screw geometry. Fingers crossed.

Good luck and remember to have fun! Post some pictures up of your new to you, Bug!
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[72Ladybug]

Thank you VWJimbo.

I knew what i was getting into. I was just foolish to think id be lucky enough to be problem free from the go. I intend to replace the screw but im not convinced that would make such a racket. I hope others chime in. If thats all im up against lll be letting out quite a sigh. I was hoping to find a solid bug to keep alive for a couple years until i had more time to undertake an overhaul. Since she is to be my daily, i need a fairly reasonable fix or ill have to drive till it dies and consider a replacement. Just dont have much free time to spare at the time...

Ill get some pics up in bit. Camping with the family this weekend and giving the bug a rest.

[volksnhousin]

Make sure the right amount of washers and clips are on the rocker shafts. There are two normal washers and one wavy washer in the middle for every rocker.

http://egan.me/static/files/engine/build/rocker-arm-apart.jpg

Investigate and experiment with the washers and make your problematic rocker look like the good working rockers.

[VW_Jimbo]

Agree with volksnhousin, then also go back and adjust the valves, engine dead cold. Check your oil, 30 weight or equivelent, and that it is at the correct level. The warning light on your speedo, red and green, come on with the key in the on position and go off when the engine is above 850rpms? Light flickering is normal at times below something like 700. Hard to remember all of the details!

If that is all good, post up a video, after adjusting those valves. Lets hear the difference.

Also, a cylinder drop test may be valuable. Your engine noise, to me, does not sound like a rod knock, but a drop test would let you know, or at least let you know if it is only one cylinder making the noise, and which one.
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[72Ladybug]

[72Ladybug]

Update time.

I bought some new screws and found the one I thought was particularly worn really isnt all that bad.

Here is the rocker alignment. All the suggested washers appear in place but alignment is still poor on driver side.

Screw is hitting bottom outside of valve stem.

Here is another on the same side, which, I believe looks pretty solid. Opinion?

The push rods on the passenger side are all to the side of the push tubes.

On the driver side all are right in the center.

Insight is appreciated. Can I just add washers to improve alignment? I'm also concerned the adjusting screw appears to be not only to the side but also the bottom of the valve stem, which makes me concerned the rockers are bad.



[/img]

[mukluk]

[VW_Jimbo]

[Vanillagurilla]

Get yourself a solid rocker shaft kit, 2 packs of 0.010 shims and 1 pack of 0.030 shims and build it. Once it's done, it's done. Nothing to break or move over time.

[72Ladybug]

[mukluk]

The mount block between the rocker arms should have a split in it like in the pic below, the split faces up when the rocker assembly is installed.

_________________
1960 Ragtop w/Semaphores "Inga"

[72Ladybug]

Wow. Alright. I see what you mean. It definitely doesn't match up, especially compared to the driver side.

Only the split on the rock is on the bottom side on the driver side. The split is on the top on the driver side (which is the problem side). What does it mean if the split is on the bottom of the side that is evenly aligned? Just a unique setup, possibly?

[mukluk]

The rocker arm mount blocks have a built in offset to help set proper rocker arm geometry, installing them in the incorrect orientation will mess that up. The split type blocks must be installed with the split facing up and the beveled edge away from the head.
_________________
1960 Ragtop w/Semaphores "Inga"

[72Ladybug]

[mukluk]

Would you replace your steering wheel if it was installed off kilter? Do you throw away and replace your shirt if it is inside out? No, you would remove and put it back on the correct way... same thing applies in this case. I cannot fathom why it would be a bummer that it's in need of some easily corrected maintenance.
_________________
1960 Ragtop w/Semaphores "Inga"

[72Ladybug]

[Floating VW]

It's possible the deck height of your engine was changed during the rebuild, or perhaps a different cam grind or aftermarket lifters were used, and this has thrown your valve train geometry off a little. You may need to check and re-set it (this should have already been done by the engine builder, but unfortunately, it slips through the cracks sometimes).

After you get your rocker shafts mounted correctly, take a magic marker and "paint" your valve stem and tappet faces. Turn the engine over by hand through one rotation, and take a look at the marks left on the faces. Here's what I look for when checking valve geometry:

You can also use this method (image borrowed from the gallery). At half-lift, the tappet should be in a straight line with the valve stem:

If you find that your geo is off, there is plenty of info here on the samba on how to set it up correctly.

I don't think it makes much of a difference if the tappet strikes the valve stem dead on in the center, instead of off to the side a little bit. Apparently, it's the up and down motion of the coiled valve spring that rotates the valve, not so much the off-set of the tappet on the valve stem.

Also, while you've got it all apart, it might be a good idea to take some vinegar and clean all the rust off your rocker shafts and arms. Clean metal = happy engine!

Good luck.
_________________
"It's time you started treating people as individuals, rather than mathematically predictable members of an aggregate set, regardless of how well that works."

[72Ladybug]

I think ive got this sorted out now. I spoke to a local pro and he was able to not only show me but provide some additional insight. Ive always spoken to the head mechanic/owner but today i met a his som who has been servicing this car since before i owned it. While the first dude was helpful he did not express much concern. The guy today said the engine has made the sound as long as he's seen the car which was shortly after the rebuild. He is concerned its internal and said he's only ever heard this sound on 1 other bug that is still driving fine after some years. He thinks it was in the rebuild. Possibly a worn seat for the rocker lifter or a loose cylinder swing pin (if i remember correctly). Ill be looking into more about these over time. He suggusted either a full tear and investigation or drive until something becomes more apparent. Even with a complete split it may be a worn case at which I'm basically getting a new engine. Im going to reassemble and drive.

I also learned my rocker positioning isnt all that bad and the reasoning for the split being up is the collection of oil for the block. I was under the impression the orientation would have an impact on rocker positioning. Ill flip both up and get her back on the road.

Thank you for all the insight. I think i just needed to see it in person.