Hydraulic Valve Adjustment and Associated Noise - kinda long

[vwlover77]

I don't see what the point of a different pushrod length would be. If I'm undertanding this right, Strop can back off the adjuster and get clearance between the adjuster and the valve. He can also tighten the adjuster, contact the valve, and then go another two turns. He's not running out of thread on the adjuster in either case. So, the pushrod length he's got sounds just fine.

[spiffy]

My thought was that it would keep the valve closed and allow for proper pre-load of the lifter, just a shot in the dark though

[Strop]

Still pondering this issue..... What would be the ramifications if my timing scale was off and I adjusted the valves BTDC or ATDC? Wold either of these conditions cause my problem?

[Strop]

Still pondering this issue..... What would be the ramifications if my timing scale was off and I adjusted the valves BTDC or ATDC? Wold either of these conditions cause my problem?

Been driving with the adjustment just a tad above zero lash. Runs OK, a bit noisy, however, power is not as good in the top end as it once was.

Gonna get it right one way or the other....

El Stropo

[vwlover77]

Bring your Camper out to the Oktoberfest in Berea this weekend and see if some of the VW experts will take a look at it.

http://www.bereaoktoberfest.com/leakoil_vws.php

[Sylvester]

Bring your Camper out to the Oktoberfest in Berea this weekend and see if some of the VW experts will take a look at it.

http://www.bereaoktoberfest.com/leakoil_vws.php

You Buckeyes have all the fun.

[Strop]

Bring your Camper out to the Oktoberfest in Berea this weekend and see if some of the VW experts will take a look at it.

http://www.bereaoktoberfest.com/leakoil_vws.php

What day and time will you be out there???? Sounds like it could be a good time.

[Sean Gallagher]

I'm getting there by 12 noon on Saturday September 1st, but I would imagine many bus folks from LEAKOIL will roll in a little later. I could be pleasantly surprised by a few early arrivals. It's the first year we are trying it, but it looks like fun:

http://www.bereaoktoberfest.com/leakoil_vws.php

[vwlover77]

I plan to arrive mid-Saturday afternoon (which I guess means I'll miss the "VW Show"). Not sure exactly what time because of my daughter's cross-country meet on Saturday morning. But, I'm planning on camping out Sat night with my daughters.

[vwlover77]

Still pondering this issue..... What would be the ramifications if my timing scale was off and I adjusted the valves BTDC or ATDC? Wold either of these conditions cause my problem?

Been driving with the adjustment just a tad above zero lash. Runs OK, a bit noisy, however, power is not as good in the top end as it once was.

Gonna get it right one way or the other....

El Stropo

Let's reason this out.....

If the timing scale is off, slightly, we can assume that the lifter could be slightly "on the ramp" of the cam lobe, instead of "on the flat".

To adjust the valve, you loosen the valve adjuster fully, and then turn it gently until it just makes contact with the valve stem. The lifter would be fully expanded because there is no pressure on it from the valve spring.

Because of being "on the ramp" of the cam, the end of the pushrod at the rocker arm is protruding a bit more than it would otherwise, presenting itself to the rocker arm as a "longer" pushrod than it should.

Then, you tighten the adjuster 1.5 turns further, which is supposed to compress the lifter and center it in its travel while the valve stays shut. This centering is taking place from the starting point of the fully expanded lifter.

So far, so good.

But, when you run the engine, the centering of the lifter is off because the adjustment was made with what appeared to the adjuster to be a "longer" pushrod.

So, when the cam is truly "on the flat", the lifter would have to expand further, perhaps to the limit of its travel, to take up the slack in the valve train. If it cannot take up all of the additional slack, I would think you would hear the valvetrain hammering, the same effect as having a lifter that won't pump up.

There's no way this scenario could prevent the valve from closing fully, in fact, just the opposite.

I'm coming to the conclusion that your valve spring is weak or broken, because it cannot resist the pressure exerted by the fully pumped-up lifter and opens the valve instead of compressing the lifter when you try to adjust the valve.

[Amskeptic]

There's no way this scenario could prevent the valve from closing fully, in fact, just the opposite.

I'm coming to the conclusion that your valve spring is weak or broken, because it cannot resist the pressure exerted by the fully pumped-up lifter and opens the valve instead of compressing the lifter when you try to adjust the valve.

Very good analysis at the top.
Very wantonly reckless speculation at the bottom

A lifter will happily open a valve if :
it is pumped up and the metering ball is slightly stuck,
it is pumped up and you adjust the screw too rapidly
(give it ten minutes to see if it properly bleeds down and
closes the valve if it does open when you screw down)
and my favorite. . . . . .
it is already totally collapsed. (Ritter and I ran into this one)
Pull the lifter and see if the plunger is up against the circlip or down the well. Up against the circlip is pumped up, down the well is collapsed. A lifter should have a moveable plunger that is up against the circlip. If it is healthy and young, you will have to push hard to get it to move down, but it should spring back up to the circlip.
Was it you, vwlover77, who had the rash of broken internal lifter springs?
Colin

[vwlover77]

There's no way this scenario could prevent the valve from closing fully, in fact, just the opposite.

I'm coming to the conclusion that your valve spring is weak or broken, because it cannot resist the pressure exerted by the fully pumped-up lifter and opens the valve instead of compressing the lifter when you try to adjust the valve.

Very good analysis at the top.
Very wantonly reckless speculation at the bottom

A lifter will happily open a valve if :
it is pumped up and the metering ball is slightly stuck,
it is pumped up and you adjust the screw too rapidly
(give it ten minutes to see if it properly bleeds down and
closes the valve if it does open when you screw down)
and my favorite. . . . . .
it is already totally collapsed. (Ritter and I ran into this one)
Pull the lifter and see if the plunger is up against the circlip or down the well. Up against the circlip is pumped up, down the well is collapsed. A lifter should have a moveable plunger that is up against the circlip. If it is healthy and young, you will have to push hard to get it to move down, but it should spring back up to the circlip.
Was it you, vwlover77, who had the rash of broken internal lifter springs?
Colin

Wanton? WON-TON? Hmmm.. Chinese for lunch would be good....

I know Strop has done the ten-minute bleed-down thing with no effect. This lifter is on Viagra!

I have seen the lifter in person (but not the Bus). It is new and clean inside and out, with a metering disk instead of a check ball. The spring was intact. (And yes, that was me with the broken lifter springs).

I hope I can take a look at it in-situ this Saturday!

[Sean Gallagher]

I'll better bring my tool box, (and my floor jack), in the event you guys get really adventurous.

[Strop]

There's no way this scenario could prevent the valve from closing fully, in fact, just the opposite.

I'm coming to the conclusion that your valve spring is weak or broken, because it cannot resist the pressure exerted by the fully pumped-up lifter and opens the valve instead of compressing the lifter when you try to adjust the valve.

Very good analysis at the top.
Very wantonly reckless speculation at the bottom

A lifter will happily open a valve if :
it is pumped up and the metering ball is slightly stuck,
it is pumped up and you adjust the screw too rapidly
(give it ten minutes to see if it properly bleeds down and
closes the valve if it does open when you screw down)
and my favorite. . . . . .
it is already totally collapsed. (Ritter and I ran into this one)
Pull the lifter and see if the plunger is up against the circlip or down the well. Up against the circlip is pumped up, down the well is collapsed. A lifter should have a moveable plunger that is up against the circlip. If it is healthy and young, you will have to push hard to get it to move down, but it should spring back up to the circlip.
Was it you, vwlover77, who had the rash of broken internal lifter springs?
Colin

Wanton? WON-TON? Hmmm.. Chinese for lunch would be good....

I know Strop has done the ten-minute bleed-down thing with no effect. This lifter is on Viagra!

I have seen the lifter in person (but not the Bus). It is new and clean inside and out, with a metering disk instead of a check ball. The spring was intact. (And yes, that was me with the broken lifter springs).

I hope I can take a look at it in-situ this Saturday!

Well..sorry I missed meeting up with you guys in Berea, I would really have appreciated having someone else listen to my engine and possible assist here.....

Maybe we could meet up somewhere else in the near future....

How was the event?

thx

el stropo

[vwlover77]

I'm still on the hook to arrange a meeting with you, me, and Sean Gallagher at Whitey's in Richfield!

Geez, with the kids back in school and running 2 cross-country meets a week, it's tough to plan anything!

The Oktoberfest was fun - check out the comments and pictures on the LEAKOIL site:

http://www.odinpowersailors.com/leakoil ... .php?t=161