That damned ticking sound

[Muzooma]

Australian 1970 bay window camper, stock 1600 DP.

Ticking noise develops a few minutes after start up.
Have searched hi and lo for the answer on the Samba.

Recently rebuilt engine after oil contamination destroyed bearings.
All new bearings, new 26 mm schadek oil pump, pressure relief pump cover, external oil filter, 30" steel shims between head and cylinders, new valve guides, stem seals on inlet valves, crankshaft not ground but within spec, crankshaft and flywheel balanced, pistons and rods weighed within 1 gram, the rest measured and within spec. Compression ration approximately 7.3 to 1.

Noise sounds just like a loose valve adjustment but it isn't. It is a mechanical sound not a gas leaking sound. It does not sound like a bearing knock. Noise starts gradually as the oil warms up a minute and a half to two minutes after start up. Am using 20W-50 high zinc. Fuel - 98 octane unleaded. Ambient temperature is 30-34 deg C. Noise is more pronounced during engine deceleration and is slightly intermittent. Thought it may have been a decking noise as the piston and rod expanding before everything else? But stripped it down (third time) and no evidence of decking plus 30" shims would stop that anyway. Sound seems to be more pronounced around no.4 cylinder. Cylinders were lightly honed, rings are ok. Piston clearance high but within tolerance. Checked distributor drive gear, wear is in correct location on gears, bottom spacer is there and spring above. Have rocked the crank back and forwards at TDC, minimal sound, oil pump gear is only significant sound but is what is expected. Fuel pump drive rod wear is in the correct location on the distributor drive gear. Sound seams to happen once every revolution but difficult to tell. Have checked springs between rockers but all seem Ok and I guess they would make noise all the time if faulty. I really thought this was a decking noise but now am completely stumped. Need a plan to eliminate possibilities.

[airschooled]

Have you tried pulling one plug wire at a time to narrow down the cylinder?
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[williamM]

Had a worn shaft on the fuel pump drive me nutter once.
_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!

[Starr1969]

Just a guess, but in my 69 Beetle, I have an external regulator that ticks just like that!
_________________
HERS: "Starr" 1969 toga white w/ sunroof
HIS: "Orange Crush" 1974 Super
OURS: 1976 Riviera Camper...needs engine work

[Muzooma]

asiab3 - Meant to do the plug wire test but clean forgot before I pulled it down, was sure it was a decking problem. Will be the first test when I reassemble tomorrow.

williamM - You mean the pin inside the fuel pump that holds the lever in place? or the rod that sits on the dizzy drive cam? I have a couple of spare fuel pump drive guides (the plastic bit) will try switching that out. Fuel pump is new.

The noise starts literally a minute and a half after start up. Is it more likely that the oil is thinning at that point and allowing something to tap or is it more likely that something is expanding and creating too much clearance?

Anybody know what parts expand first in the warm up cycle besides the obvious being the piston.

Star1969 - regulator on the bus is way over to the right on the bulkhead, noise is definitely an engine internal noise. Used a piece of hose and seems to be loudest around no.4.

Was wondering what I could do with the valve gear to test it. I have another set of rocker gear but will swap that as a last resort. Was wondering how long it takes valve gear to settle in. Have adjusted clearance a couple of dozen times, even re-domed the studs so they would adjust properly. Engine runs sweet for the first minute and a half with just the slightest normal tappet chatter. Then this other tap starts.

Pist ring gap was towards the end of tolerance but still within, can they make a tapping noise?

Guess I have to put it back together and start testing.

This engine has a secret that it doesn't want to share.

Thanks for your help

[williamM]

New pump- huuum- maybe no spring in distributor drive/ wrong fuel pump rod length for new pump?

Back to the lifters-? did you feel any slop in the lifter bores? And if you have to pull the rocker shafts, check the push rods for scuff marks and straightness.

Piston to cylinder wall clearance has to be pretty far off before it noticeably clatters over engine noise- same with small end of the rod.

Try to sound out the oil pump/ if it is hitting cam rivets you need to fix that NOW.

You might run it up to temp- and try to turn it over by hand and see if there is any tight spots.

I have put the wrong screws in a distributor only to have them tap on the weights under the points plate- but now we are really reaching out there.
_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!

[Muzooma]

I did suspect the lifter bores as the oil was initially quite contaminated.

Dizzy drive spring is not missing and had two different length fuel pump rods but the longer one is the only one that worked with this pump. The distance it rises above the spacer guide at the lowest position is about the same as the recess up to the lever in the pump. The other rod is almost flush with the top of the spacer in the lowest position and would not touch the pump lever.

Push rods are aluminium and are strait. There is scuff marks from previous build where one or two were touching bent tubes but I spent considerable time eliminate that problem on this build with care and new tubes. Will inspect that again when i put the heads on tomorrow.

Thanks for confirmation on the piston clearance. I have driven cars with definite piston slap and is a different noise than what I am getting. The small ends were replaced and are at the closer end of tolerance. The wrist pins slid into the pistons without heat but were not sloppy in the slightest. Side movement was minimal.

Cam rivets is interesting. I put a double thrust bearing set in and end play was negligible. Backlash between cam gear and crankshaft gear is almost negligible. There is considerable backlash between the brass crankshaft gear and the dizzy drive gear (maybe 30") but the wear is even and not aggressive. Will keep the rivet clearance in mind. I guess there is no way to inspect that without splitting the case. will drop the oil filler off and see if I can check with a flashlight then check when hot later.

yeahr if it was the bolts in the dizzy it would be doing that all the time? This is something to do with the oil/ engine parts getting warm.

With the heads off and using a pushrod to suck the lifters towards the outside of the engine the lifters catch slightly before they are fully seated, maybe a slight ridge at the end of their usual travel but not significant. I have used the same cam so it's not like I am trying to force the lifters past their previous wear pattern. This engine looks like it has had several rebuilds and I am not sure what cam is in it. Seem to remember it having a VW stamp on it though if that means anything. Think the engine may have come out of a 74 bug.
Trying to move the lifters sideways with the pushrod, there doesn't seem to be any play with the engine cold but maybe there could be at the cam side. I would suspect that would sound more like a knock than a tap, maybe I am wrong. If that is the problem and they are tapping as soon as the oil warms how do I confirm that?
I guess try another set of lifters, last thing I want to do is split the case. One of the VW rebuild shops over here suggested using strait 50 weight oil. I guess that wouldn't hurt with ambient temperature here usually over 30 deg C. You think that could take up the slack knowing that the engine is quiet when the engine is cold?

Other thing I was thinking is maybe the valves were hanging up a bit once they are warm as the new guides are a close tolerance. But I guess if they are slow to close that would effect the running of the engine and that seems to be completely fine. Also the symptoms were there before i had the valve guides replaced so am sure that is not the problem. I am not using a lead additive as I read that heads with steel valve seat inserts don't need it but could this make the valves hang open due to inadequate lubrication? And could that make the tapping sound similar to a widely adjusted valve clearance or would there be worse symptoms?

Lots to test. Thanks

[customcityjim]

Use an automotive stethoscope and you will find it real quick. You can also use a long screwdriver, put it up to your ear and touch different places that you think the sound is coming from, the louder it gets the closer you are to the problem.

[williamM]

You can check the cam to oil pump clearance by simply pulling the pump and looking for pump metal on the rivets.

It's interesting that the lifters want to stick for a second. There might be something to look at. as a sticky one holding a valve for a micro second and then snapping shut might be your noise. Now here is where it gets fun- get it up to temp- remove the valve cover where the noise is and start it up. You'll lose some oil ( I had a window cut valve cover I used for this-) And while its running, push on each rocker searching for one that changes the sound. While you are there you can see if one of the push rod tubes is not oiling- that would also make a lifter seize.
_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!

[wihr]

I had the rivets on the camshaft drive gear loosen up over many years. It made the "tick, tick" noise when warm until it let loose and destroyed my engine. Try isolating the noise with a stethoscope.
_________________
WIHR

1970 Campmobile "Van Ordinaire"
2009 Lincoln Town Car "Behemoth"
1969 Lambretta 150 DL "Nina"
1962 Matchless G 12 CS 650cc

[Desertbusman]

From all you've said there is a lot to comment on. But here is just a few comments:

- It's not your noise problem however shims go between the case and barrels, not under the heads.
- If contamination had destroyed bearings it might have also eaten the lifter bores. That could be your noise. If you pull it down carefully check the bores. Bronze inserts can remedy that.
- You keep adjusting the valves. Why? Are the clearances changing?
- All the piston arrows pointing towards the flywheel? Are you double sure? You can inspect in thru the plug hole. A friend had an engine built and it had the same tick symptom you evidently have. Very difficult to troubleshoot. The builder finally agreed it had some issue and pulled the heads to discover an upside down piston.
- Fuel pump pushrod setup is in your service manual.
- To answer your question- Exhaust valve is first to heat then head and piston.
- You can't try different lifters unless you split the case.
- 26 mm schadek pump is no clearance problem concern with a stock cam. With an aftermarked bolt on cam gear it could be.
- Double thrust cam bearing is good but stock single thrust is ample since rotation of the gears forces cam fully forward when running.
- A mickey mouse shop suggested straight 50W?? Do you want it good or do you want to hide and ignore the problem? People used to dump in straight STP goop to eliminate sounds so they could sell a junker.
_________________
71 Superbug
71 Westy

[Muzooma]

Great info thanks.

A frustrating day yesterday re-measuring everything I could.

I took no.4 piston off and remeasured the ring gaps but they are still in spec. I did notice the top ring has a bevelled edge on the inside of the top surface but couldn't see any markings to see which way up they were supposed to go. Am guessing they are correct as the way the bevel is would hydraulically aid their sealing ability. The ring side gap was .005", which is the upper end of spec. I measured the skirt at the lowest edge perpendicular to the wrist pin 85.41 mm and parallel 84.95. The cylinder is has nil wear. Don't think there is a problem here as the pistons still have the machining pattern on the outside surface and don't appear to have run too hot.

I also noticed that this piston was the heaviest piston as I had to remove almost all of the four lugs on the inside of the skirt when I balanced them.

I also suspected that the wrist pins might be too loose in the pistons and the wrist pins too worn at the bearing but the last time I stripped it down I put new small end bearings and this time they all feel good and tight. I could tilt the piston maybe one degree from side to side which I think I worked out was acceptable. I had to heat the piston slightly to take the wrist pin out.

I put steel gaskets in between the cylinders and heads during the last build as the heads had a slight sealing problem and I wanted to lower the compression slightly as I live in the tropics and overheating is an issue. This time I pulled the engine I was sure it was a decking problem and was going to install shims between the cylinders and case but there is definitely no decking problem as the raised lip has not been machined out of the heads and there is a good clearance between the top of the piston and the end of the cylinder (0.8 to 1.4 mm) The cylinders were seating correctly in the heads as there was clear compression of the gasket/shim all the way around. I have now noticed that the lip in the right hand head is thinner by on average half a mm than the left head. Guess that means I could have higher compression in the right head, seem to remember cc ing the heads to find the compression ratio, interesting that I didn't notice the difference, maybe there was none. I have noticed that where the cylinder has bedded into the gasket it has burred the inside edge of the gasket up towards the piston (0.3 mm) but by my measurements this would still give a 0.5 mm clearance and it doesn't look like it has been touching anyway. There is only one section where the gasket is burred up significantly and it's at no.1 piston away from where I think the noise is coming from.

Also interesting is that the exhaust valves on the left head are a mid to light brown color whereas the exhaust valves in the right head are black soot like the rest of the combustion chamber. A clear heat difference. I understand the excess soot is from the fact that I haven't had it running hard out on the road yet. Has been a long term project so most of it's time since rebuild has been spent under warmup with automatic choke trying to find this noise. Now wondering again if the exhaust valves on the left head are running hotter because they aren't closing properly however engine was running great. Maybe I should do a compression test after it's warmed up. I don't have seals on the exhaust vales as I figure they are under compression so won't loose oil there. Anybody had problems with new guides being too tight and grabbing the valve when the valve heats up? Guess if that happened they would just stay open till the piston hit them but that is definitely not happening.

Not knowing how long it would take for the valve train to seat itself into place I kept checking the valve clearance until I was certain that it had stabilized. Was a bit rusty on my technique but the last few times I am confident that I got it spot on. So no I don't think the clearances are changing now.

Pulled heads off. All arrows facing towards flywheel.

I managed to get my fingers in to move the no.4 exhaust valve lifter backwards and forwards. There is a definite ridge where the lift would be at maximum and was able to induce a slight tapping sound when I used a push-rod to push the lift down against the bore wall. There is a very good chance that this is the problem.
Seems possible that when the oil is cool and thick the lifter positions itself in the centre of the bore and misses the ridge but as soon as the oil heats and thins the lifter is allowed to touch the ridge. Knowing that the lifters ended up in different bores on this last rebuild I guess the slightest difference in lifter length, a longer one going into a bore where there was a shorter one could cause a tap.
Knowing that the lifters are not new and that they wear to the cam there could be a considerable difference in lift height and therefore length of bore wear. This could mean that just one lifter is going significantly past the wear limit in the bore but more likely more than one. Anybody out there who has relined the lifter bores and definitely got rid of a tapping noise I would love to hear your story. I figure this is something that might wear itself away and not be critical to engine longevity as long as I keep good oil up to it. I don't have the time or resources at the moment to re-line the bores but will do so at the first opportunity. Will consider using strait 50 oil until that happens.

As I don't know what cam is in this engine and think that it came from a 74 bug that a young fella had wrapped around a tree, I had a bit of a read on cams and there is some mention that cams themselves can be noisy. Some mention of how fast they come off the lift and maybe wether the spring can keep up with the fall. I'm sure that it would be a lot more chatter if this was the case but I seem to be getting only one tap per revolution. Hmm so that would mean that if the tap is coming from the lifter bores it maybe just one that is more excessively worn than the others?

Another observation, there was a thin film of excess rubber seal between the rocker shaft brackets and the heads. Could the brackets have been see sawing on this thin rubber film. Unlikely but a possibility? And if so how would heat effect when it happened. And wouldn't it be affected by all the rockers.

Ok symptoms again - tap that starts slowly from nothing a minute and a half after start up and appears to tap once per revolution and that is slightly intermittent and less excessive under engine acceleration and more excessive under engine deceleration. Then quietens slightly once case is warm maybe about fifteen minutes later, although that's not conclusive as the noise appears to change characteristics slightly if the engine is revved high or taken for a drive. Maybe clearing soot stops it quieting itself.

You would expect a tapping noise to be coming only from the parts that go backwards and forwards, ie the pistons and rods and the valve train. Everything else is rotating so would create a different kind of sound. So in all those backwards and forwards parts what is going to heat up enough in a minute and a half to start hitting something that wouldn't when it was cold. Valves expanding .... no. Push-rods expanding? ... no. Piston and rod combination .... possible but on inspection not happening.

What else goes backwards and forwards? hhhmmm. Wondering about the oil temp balance piston and spring. Could an oversize oil pump be creating a situation where the piston oscillates on it's seat? Not likely as it wouldn't be once per engine revolution but a continuous tap.

Is it possible to take the push-rods out of one cylinder and run the engine on three? That way I could eliminate lifter travel for that cylinder?? That could be a definite check. It would isolate valve train noise from piston rod noise.

I'm guessing that if the oil was contaminated it would find it's way equally to all bearing surfaces? Or would it effect those bearing surfaces closer to the source more than the rest? Don't think it would make any difference.

Ok so possibilities so far from my observations and measurements.

- Lifter bores ..... very likely
- Valve guides .... less likely
- Piston decking ....less likely
- Pistons clearance and piston ring clearance .... less likely
- Cam rivets .... less likely
- Rocker side shift ..... why would heating cause this to change?
- Oil temp balance piston ... not likely.
- Insanity .... more likely lol.


Seems there is a lot of things about these engines that the books don't tell you about. Maybe the possibilities are too numerous to mention but I get the feeling there are a few trade secrets out there waiting to be shared.

Ok enough valve chatter from me, time to put it back together.

Thank you kindly for your interest and knowledge.

[Desertbusman]

Just for fun have you refered to and understood this book word for word?

Probably not your tick tick but I don't understand your reasoning on head shims. Barrel shims set your deck height like evidently you are doing with your head shims. However you talk about sealing issues which I don't think makes sense. You are trading one sealing surface (barrel to head) for 2 sealing surfaces and double the chance for leaking. (barrel to shim and shim to head)
If you say the barrel to head seal is a problem then throwing the shim in there is double the sealing problem. Have you lapped the ends of the barrels into the head using valve grinding compound? I've never had that "joint" with leakage concerns after lapping.

Goop under the rocker shaft stands is wrong. There is a O ring on the stand studs. And the goop might prevent the proper tightening torque or else it will tighten then change once the goop heats up.

Seems like most T-1 peeps always use a new cam and lifters on a rebuild. Since that is where failures can happen, a new cam doesn't seem less important than new bearings or rebuilt straightened and resized rods.

So if 50w oil quiets the tick is masking the tick worth jeopardizing all the other components. In other words are you content with 50W lubricating bearings, gears and everything else?
_________________
71 Superbug
71 Westy

[Muzooma]

I am currently using 20W50 high zinc as I am in the tropics. Is there that much of a step up to strait 50? Wouldn't it be the same as running 20W50 when the oil is cold? How would heavier oil jeopardize the other parts? I don't know, that's why I haven't done it yet.

What I am trying to do is ascertain if the tapping noise is terminal as I have a 2000 mile journey in front of me. My reasoning is that something like the piston hitting the head with all that momentum is a terminal situation, but something like a lifter touching a slight lip at a glancing blow is most likely not terminal. I have fitted full flow filtering to take away the risk of oil contamination during any wearing effecting other parts. The 50 weight is either going to fix it or not. I am aware that strait 50 might be less inclined to travel through the oil cooler but I am fitting temp gages to make sure it won't get too hot. I didn't build it to race, just to get me there.... and back with a bit of luck.

I put the shims in the heads, they are a soft gasket white metal, to take up a badly scored surface. Looks like one of these heads had been bouncing around loose for a while or just burnt through a badly fitting rebuild, either way it really needed to be machined, past using seating compound but I don't have the machining option at this stage. Anyway the shims solved the problem and have created a good seal. I am not particularly worried about them as long as they don't burn away when the going gets tough out on the highway. I have put this engine together with many old parts closely thinking about what I can make work or not. The heads are not a matching pair but I accept that at the moment. One of them had been welded around the plug hole. Later I will try to improve what I have but for the moment I just need to get it past a self destruction possibility. I took care to balance everything I could and the engine actually runs surprisingly well and smoothly except for this one tick. I just found a video that is very similar to what I have going on.

http://www.youtube.com/watch?v=rEEoLmjFU5k&feature=youtu.be

Only difference is my engine doesn't start tapping for a minute and a half after startup. Sounds completely like valve train noise but valve lash is good at .006". Maybe I need to try .005". But what gets me is it just seems to be one tap per revolution. Am I wrong if it's similar to the one in the vid? Am also really wondering about rocker side slap but how would this be effected by heat, wouldn't it just make a noise all the time? Knowing that the valve gear is ancient, maybe the springs that hold the rockers from moving sideways are due for replacement. Is it possible to put solid shims on the shaft without replacing the whole setup? Have read something about this but don't know what it entails.

The stuff under the rocker stands is where the rubber O-ring has expanded outside of it's recess. Maybe an oversize O-ring. Don't think it is the problem but it has been removed.

[Muzooma]

I have four different books on the bus. None of them mention what noises to expect when things are past their wear limit. Guess they were all written when these things weren't that old. Maybe the one you suggested does. That would be nice.

[Muzooma]

Oh and I researched for five months over the net from everything to understanding the oil temp balance control system to the automatic fuel pump adjustment on a 34 pict 4. All of it has made good sense until I got to this tapping business. But I guess that's what you get when you play with old parts. There has been some great and invaluable suggestions hopefully giving me the right clues to locate the problem.

[williamM]

I vote for sticky cam follower=

The straight 50 wt will cut its own clearance- by that I mean it will not lube a clearance it can't get to so what ever bearing is in there will wear till the 50 wt can provide lubrication. Race motors are built with excessive clearance and less bearing material against the crank and rods- SO 50 weight has plenty of room to work there and the motor has less friction due to the smaller bearing sizes . An engine built tighter than .001 clearance needs light weight oil to fit in the close tolerances there.

You might get away with the tight cam follower bore (the ridge) by having the lifter wear its way in to oil clearance. Next time--- you can stick your pinky down the hole and feel for a ridge and maybe open it up a little with a brake cylinder hone- just don't hit the main part of the bore.
_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!

[Muzooma]

Ok I've been a bit distracted but am starting to put all the bits back together again inspecting everything very closely.

I started another post about water injection and the use of waste heat. If you want to read it it's on the bay window forum.

A few questions -

Knowing that the distributor drive gear is pushing one way against the distributor so that backlash in the drive gears can be allowed for, at what point does back lash become too much. Was looking at timing with the engine running and the timing didn't seem to be unstable but when I have the dizzy cap off on move the rotor there seems to be about four degrees of backlash and thats not including the advance mechanism in the bottom of the dizzy which looks to be a further 9 or ten degree. Doesn't seem to be any mention in the books I have so maybe it is unimportant.

Do you have to pack the new fuel pumps with the plastic cam full of grease? Thinking not, but maybe wrong.

I put the heads on and fell for the old trick of leaving the air deflector plates out so off they came for another go.

I'm pretty sure now that it is the worn lifter bores that are creating the noise. Not sure why the noise would be more pronounced while the engine is in deceleration. Maybe under acceleration the case is trying to pull away from the crank just that smidgeon opening the distance between the cam and lifter bores. Or maybe less gas pressure acting on the valves so the lifters are allowed to float that little bit higher off the end of the cam. I don't know. Must be a reason though. Any one know or can take a guess?

So will probably run a strait 50 weight oil as the crank was not at the low end of spec when I put it together and the cam was not new either. Should be Ok with the ambient temps I get here but am a little concerned with getting enough oil through the cooler. Maybe I should get a new oil balance spring or at least test the old one for tension and length. that's not hard to do.

Another thing I noticed while putting the heads back on is that the oil gallery in the end of the rockers has been welded up. Is this a later modification to increase oil pressure at the rocker shaft? Was wondering how oil gets to the valve stem heads. Isn't oil supposed to spray up over the rocker cover to aid cooling? Or does it all happen from the excess coming from between the rockers and rocker shaft?

Had a look at all the lifter bore oil gallery and valve train mods but it won't happen on this engine for a while. I have another 1600 DP that I want to build and put in my A&S beach buggy. It's a bright orange thing. I had the engine I am currently working on, before it was rebuilt, in it for a few days at the time of my dad's eightieth birthday. With the 34 pict 4 carb installed, wow! did it go, the power band was amazing, thought the thing was going to wheel stand a few times. Completely scared the day lights out of my dad but he still had a big smile on his face
Unfortunately it started making noises pretty quickly and I later found out that while it had been sitting with the sump plug out a wasp had decided to build a nest inside it. Very quick engine destruction So I think that is the issue I have now. I have measured and accounted for all the other wearing surfaces except the lifter bores which didn't feel too bad when I was putting it together but I definitely remember there was some play without oil. I went to the trouble of pulling all the plugs, cleaning the galleries and fitting screw in plugs along with the external full flow filter just to make sure that doesn't happen again by wasp or any other nasty contaminate
I couldn't imagine at the time that they would make a noise as it seemed the cam is holding them to one side of the bore with it's rotation. Maybe that's why the noise is less noticeable at higher rpm but at lower rpm the lifter slides down the back of the cam so to speak and is pushed back the other way making the tapping noise.
Then to think that there is a wear ridge at the end of usual travel which could be the sole reason for the noise. At any rate heavier oil will undoubtedly help until the next rebuild after I have done the other engine. The other case was a wasp free case haha and I have checked the lifter bores and they are all good. Is great that I have got to practice on this engine. Not sure it was going to work out as it had already been line bored to .100" so I had to search all over the net to find the last set of bearings in existence that would fit. Did an international call to a shop in Washington State and they had a dusty set out the back on a shelf, so lucky!

Cheers!

[scrivyscriv]

[Muzooma]

Thanks for the info and direction Scrivy.