WBX

[itchyfeet]

Valve train noise is worse now with old tappets returned, the ticking noise is gone ( due to missing spring washer on rocker shaft) but when hot the general noise is loud and very noticeable.

I wondered if it was big end but the oil pressure being 3 bar hot 2000 rpm and 1 bar hot idle is, I'm told, not indicating big ends ( Marco Mansi's interpretation, he knows his onions).

I'm interested to solve this mystery before removing engine, any ideas?

[tobydog]

Noise caused by rocker shafts/ rocker bores worn?

[itchyfeet]

Noise caused by rocker shafts/ rocker bores worn?

could be but if tappet bores worn I'd expect low oil pressure.

[itchyfeet]

looking at a cam I'm also wondering if adjusting both valves valves at TDC is wrong, the inlet will be just opening at TDC and exhaust not quite closed

this is what Haynes sys to do but I'm now thinking its wrong?

[ajsimmo]

looking at a cam I'm also wondering if adjusting both valves valves at TDC is wrong, the inlet will be just opening at TDC and exhaust not quite closed

this is what Haynes sys to do but I'm now thinking its wrong?

You have the wrong stroke in mind, Paul. It's TDC on the compression stroke, so inlet closed much earlier (around previous BDC), and exhaust won't open until around next BDC.

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[ajsimmo]

It's very intriguing that those new followers made such a difference to the oil pressure. I'm struggling to figure it out. I wonder if the pressure is lost through or around them. It's a massive difference, far more than you'd anticipate. Thanks for doing the test. It offers up another possible fix to be considered for engines that come in with BOD!

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[itchyfeet]

looking at a cam I'm also wondering if adjusting both valves valves at TDC is wrong, the inlet will be just opening at TDC and exhaust not quite closed

this is what Haynes sys to do but I'm now thinking its wrong?

You have the wrong stroke in mind, Paul. It's TDC on the compression stroke, so inlet closed much earlier (around previous BDC), and exhaust won't open until around next BDC.

Sent from my ONEPLUS A3003 using Tapatalk

Ah yes of course, what a plonker, can't have a spark with open valves

[itchyfeet]

It's very intriguing that those new followers made such a difference to the oil pressure. I'm struggling to figure it out. I wonder if the pressure is lost through or around them. It's a massive difference, far more than you'd anticipate. Thanks for doing the test. It offers up another possible fix to be considered for engines that come in with BOD!

Sent from my ONEPLUS A3003 using Tapatalk

I think its the internal tolerances at fault, they compressed far too easily when priming them.

There is a hole in the side to the upper internal cavity, this hole is fed from the oil gallery directly where the oil pressure is measured, oil passing through the tappet and out past the plunger will cause oil pressure to drop, I think a little is supposed to flow through and up push rods but these probably had too much flow.

[itchyfeet]

Valve train noise is worse now with old tappets returned, the ticking noise is gone ( due to missing spring washer on rocker shaft) but when hot the general noise is loud and very noticeable.

I wondered if it was big end but the oil pressure being 3 bar hot 2000 rpm and 1 bar hot idle is, I'm told, not indicating big ends ( Marco Mansi's interpretation, he knows his onions).

I'm interested to solve this mystery before removing engine, any ideas?

I think I have found some of the noise, I think it was running very lean on idle and the noise was pinking, it's LPG and set slightly lean on idle to stop the closed loop stepper closing down ( this is not good for burning off the lights) but somehow it's got very lean ( maybe because of winter maybe an air leak), tweaked it today and it's better, still noisier than it was. This is why you need an air fuel gauge with LPG

[itchyfeet]

I have been thinking about the oil temp sensor on this engine in the pressure relief valve plug, it's far from ideal, probably reasonable in summer but readings way out in winter, the relief valve only work when cold and pressure high, when hot almost no oil is being bypassed in normal driving because the pressure is lower, this means the temp sender is relying on conducted heat and in winter that's inaccurate.

P1030500 by Paul_Barr, on Flickr

I considered drilling a hole in the crankcase but having measured wall thickness is not enough without adding some sort of bush.

I have thought about fitting a sensor to the oil filler tube by welding a boss in but the metal tube is inly 1mm thick and welding a large boss into a relatively small tube is not going to be easy. They suffer from rust when new and plated so once welded they will likely rust faster andf the sensor is still not inside the engine.

I have thought about a spacer with the sensor in and longer studs but there is no room to move the tube away from the crankcase.

I have though about removing the oil filler tube and making a plate with the sensor in and that's what I did today as an experiment.
Still need to weld the bush in, paint it and fit it.

P1090672 by Paul_Barr, on Flickr

This leaves me with the need to fill the oil somehow and the breather tower is the obvious choice.

The oil filler tube needs a funnel any way and this funnel tends to fall out, it's a rubbish design IMO and so happy to try something else.

Add to this that some vans suffer from mayo in the tower, perhaps by short journey or perhaps by weeping lower barrel seals it seems a good idea to be able to inspect and clean.

P1090669 by Paul_Barr, on Flickr

Also all the breather towers I have ever seen are long since broken, the rubber membrane has perished and it is no longer a valve just an open breather so no loss cutting it open.
Dia 40mm hole saw then filled out to be a tight fit so no seal needed, tube is dia 42mm ish


20180220_072324 by Paul_Barr, on Flickr

next I got an old broken oil filler tube plastic part ( Thanks Mark) cut it down and added a hole to align with the vent

P1090657 by Paul_Barr, on Flickr


it's a push fit in the tower

P1090659 by Paul_Barr, on Flickr

a piece of 15mm pipe prevents the tube turning when you fit and remove the cap ( which can be quite stiff) and provides some air flow restriction.

P1090661 by Paul_Barr, on Flickr

replaced the insert

P1090665 by Paul_Barr, on Flickr

fitted

P1090670 by Paul_Barr, on Flickr

I'm planning on trying a separate PCV valve, I bought one a while ago but never fitted it, just waiting for some 19mm silicone vac hose to arrive

[Oldiebut goodie]

Going back up to welding boss into thin rusty tube - the obvious answer is to braze it in place. Sometimes the old ways are best. Of course it would mean that it isn't in the optimum position still.

[itchyfeet]

Going back up to welding boss into thin rusty tube - the obvious answer is to braze it in place. Sometimes the old ways are best. Of course it would mean that it isn't in the optimum position still.

yes good idea, I might try it but it's 35 years since I did any brazing and the tube is an expensive part to experiment on.
this bush is quite small for an NPT thread if you had an M14 it would be much bigger, cutting a hole that big in the tube would severely weaken it.

[CJH]

I really like that breather tube mod for topping up the oil - it's a much more sensible place than the stupid near-horizontal filler that VW designed that inevitably leads to slow fill-ups and oil spilling all over the bumper and the flap hinges. But for the sake of completeness I feel I have to mention the drain plug temperature sensor.





It seems to work for me. Of course it's difficult to know how accurate it is, and whether the sump oil temperature is representative, but my oil temperature gauge seems more or less pinned at the temperature setting of my thermostatic sandwich plate, so I'm quite happy that it's showing a representative temperature.

[itchyfeet]

yes but that has it's drawbacks, hard to get a torque wrench on ( I guess you use a box spanner) and they and the matching gauge are expensive, also the connection is very exposed.

Cheap gauges are not M14x1.5

This sump is M18 and many are M16

1469781832 by Paul_Barr, on Flickr

[CJH]

yes but that has it's drawbacks, hard to get a torque wrench on ( I guess you use a box spanner) and they and the matching gauge are expensive, also the connection is very exposed.

Yes, it needs a slightly modified box spanner because the sender nearly fills the recess where the sump plug fits. I used a bench grinder to thin a cheap box spanner, and I can get a torque wrench on the other end.

Cheap gauges are not M14x1.5

.

Not sure I follow. It's only a sender. Won't a cheap gauge work from the same sender?