Problem with hydraulic cam followers

[Incorrigible]

I've been trying to cure a bloody annoying top end rattle, and am now wishing I'd never bothered.....

I've removed and inspected the cam followers, and they seem fine. However after bleeding and refitting them they seem to have adjusted themselves. The adjustment is via a one way valve and spring in teh follower centre (as with most of them) but it adjusts the centre out to such a point that I now no longer have any compression (all exhaust valves are slightly open all the time)

Any suggestions short of buying 8 new followers ?? I just need a way of holding the self adjuster in place until its all assembled

[rev-erend]

Ben - I'm no expert here .. but is it possible that you have used oil that is too thick when pumping up the lifter and it's causing the lifter to stay fully extended.

[stevieturbo]

So its went from a rattle, where the lifters are too loose, to them being too tight, and holding the valves open ??

Did you defo re-assemble them properly ?

Have you tried replacing them ?

Is it every exhaust valve....and if so, why only the exhaust valves ? What are the inlet valves like ?

[Incorrigible]

Thanks for the replies

Have I definitely re-assembled them properly ?

Dunno, but pretty sure I have, there's only 3 bits after all

What's the inlet like ?

Haven't bothered taking it to bits. I want to get this side fixed first. Also fairly sure the noise was coming from no 4 exhaust, annoyingly I think I've found the cause of the rattle; the belt tensioner is intermitantly going slack which was causing backlash in the cam angle sensor

I've re-assembled them with jizer instead of oil (thinking that would be at thin as oil could ever get) and still the centre remains pumped up, the one way valve prevents the fluid from getting out (does it's job as far as I can see, although my assumption was that they'd adjust themselves down as well as up ) assembling like this would still cause the lack of compression

I've also tried running it with the centre piston with air in it. At least the engine runs like this but obviously I've now got the rattle I thought I was curing in the first place

So to answer your question, it went from a completely unrelated rattle to one I completely understand that I've caused myself

There's a description of some bloke doing exactly what I'm doing (with similar tappets) here he seems to think that the one way valve works both ways but I can't quite see how

Edited by Incorrigible on Tuesday 16th October 21:05

[rev-erend]

Ben

It's FUBARed..

Have a beer

[Incorrigible]

Still in the workshop, but the pub's calling

Think I'll sleep on it

[stevieturbo]

Hydraulic lifters do pump up, to remove any clearance...and then be quiet.

But on the other hand, most will also bleed down very slowly, if oil pressure is removed, due to the action of the spring forcing against the follower.
Some bleed down easier than others. Some pump up, and need to be bled down manually ( ie, in a vice or press ), although I think these types are less common in modern cars. I know some old Vauxhalls were a nightmare in this respect.

[Mr2Mike]

Incorrigible said:

I've re-assembled them with jizer instead of oil (thinking that would be at thin as oil could ever get) and still the centre remains pumped up,

Jizer? As in the degreaser you use to strip oil and grease off engine parts?

[Incorrigible]

stevieturbo said:

Hydraulic lifters do pump up, to remove any clearance...and then be quiet.

Yeah, but it's a spring that sets the clearance (pushes the tappet onto the cam, ie no clearance)

stevieturbo said:

But on the other hand, most will also bleed down very slowly, if oil pressure is removed, due to the action of the spring forcing against the follower.

Some bleed down easier than others. Some pump up, and need to be bled down manually ( ie, in a vice or press ), although I think these types are less common in modern cars. I know some old Vauxhalls were a nightmare in this respect.

These don't seem to want to bleed down at all, even with a very light liquid in them and in a vice (I've even tried thinners when jizer didn't work)

All I can think, is that I need to temporarily dissable the one way valve during assembly. Then bleed all the air out of the rest of the tappet.

[That Daddy]

What engine is it?

[Incorrigible]

Lotus Elan (new one)

Lifters look really standard though

[That Daddy]

Incorrigible said:

Lotus Elan (new one)

Lifters look really standard though

Whay K series

[stevieturbo]

Incorrigible said:

stevieturbo said:

Hydraulic lifters do pump up, to remove any clearance...and then be quiet.

Yeah, but it's a spring that sets the clearance (pushes the tappet onto the cam, ie no clearance)

Oil pressure sets the clearance. The spring is only there to keep things right during assembly...or when empty of oil.
In fact...when oil pressure is present, cant see any need for that spring at all.

[dilbert]

Sounds like you have too much oil in them, or perhaps air?
I'd have thought they are assembled dry and completely compressed, then dunked in oil where the spring then "does it's stuff" by pulling some oil in. A long time ago I did a CVH head on one of my old cars. I seem to remember that the followers were pre-assembled in the box with the new cam. I suppose that means I know nothing really!!


Edited to add, I don't think they came with any special clamps, they were just there, and I threw them in. It was a bit rattly for a minute or so, and then the whole thing went on to do another 50K to my certain knowledge, and possibly more!

I'm not sure about putting them in if they're already too big. I guess the ideal, is that you put them in and they're a bit too small.

Edited by dilbert on Wednesday 17th October 18:40

[rev-erend]

Silly question from the mechanics bible.

Did you compare the old and the new parts..

[thong]

put it back together,then turn each pair of valves in turn to full lift,this will then squeez out the excesive oil you have in the lifters.

[stevieturbo]

You would probably need to leave them for a few hours for the valve springs to squeeze the oil out.

Old SOHC vauxhall engines simply wouldnt. They had to be compressed manually.

[That Daddy]

stevieturbo said:

You would probably need to leave them for a few hours for the valve springs to squeeze the oil out.

Old SOHC vauxhall engines simply wouldnt. They had to be compressed manually.

Or left overnight assembled,this is a common complaint with this motor after doing the headgasket for example

Edited by That Daddy on Thursday 18th October 22:35

[That Daddy]

stevieturbo said:

You would probably need to leave them for a few hours for the valve springs to squeeze the oil out.

Old SOHC vauxhall engines simply wouldnt. They had to be compressed manually.

Or left overnight assembled,this is a common complaint with this motor after doing the headgasket for example

Edited by That Daddy on Thursday 18th October 22:37

[Incorrigible]

thong said:

put it back together,then turn each pair of valves in turn to full lift,this will then squeez out the excesive oil you have in the lifters.

That's the problem, the oil just doesn't squeeze out. As I said I even tried using jizer instead of oil to no avail

However, I have found the problem. Over the years (and about 100,000 miles) a very small film of what can only be decribed as "crap" has built up on the very central piston. This was rendering the piston air tight, hardly suprising that oil couldn't get out. A quick whizz with some 1200 paper and we're good to go.

Although just to be on the safe side I used Mechoil to fill them with rather than engine oil (to make sure they would reset)