Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[jonny2112]

I can see now that the cam lobes and lifters are set in pairs. If a lifter becomes noisy because it cannot maintain the gap, and is therefore being 'hit' rather than 'pushed' by the cam lobe, would it be obvious to see? Should it be out of sync with its neighbour?
Also, if it comes to removing them all and cleaning them, the guide suggests that the piston within the lifter can be pushed in and should then return to its original position. In the two new tappets I have, the piston is fully closed, and I imagine could only be opened by oil and pressure. When one is taken out of the head, it will be full of oil and could therefore be depressed. Once it has been depressed though, how would you be able to depress it again?
Sorry for the stupidity, but in my tiny brain I am obviously missing something  

[Kevin Wood]

In my experience (not with Omegas, by the way, but with very similar lifters) You can't reliably see what's going one once the engine is stripped. Some lifters will end up under compression holding a valve open when the engine stops and this will force some oil out of them, meaning more clearance if the engine is turned to take them out of compression.

If two lifters of a pair of valves on the same side of a single cylinder are compressed differently this might be a clue as to their condition, but no more than a clue, I'd say.

If the lifter has had an extended battering you may notice some extra wear on the surface but they are very hard in any case so this is unlikely to be reliable.

Again, in my experience, if you push the piston of a used lifter in the oil will squirt out and it will stay depressed. I have bought new lifters before and they were supplied with the pistons fully "in".

I don't think you're missing anything. These work by filling with oil until the slack is taken up and, once full and when the escape route for the oil is blocked, they are, for all intents and purposes, solid unless they are not oil tight.

Kevin

[jonny2112]

Thanks for the reassurance Kevin!
It would seem then that there is no way of telling if a lifter is faulty? I have two new ones, and also new cam oil seals (expensive!), but am now not sure whether or not to proceed with this particular task. I am worried about the cam bearing caps, though if I take my time I should be okay. I suppose I could take them out anyway (drivers side only) and examine them just in case something is apparent. Otherwise, if I clean them out by depressing them perhaps a fault may be recognised, for example if the piston won't depress, or is extremely stiff.
I'm hoping to get the whole thing done over the weekend, so I'll have to have a think..... :-/

[Kevin Wood]

Are the cam covers already off?

If not, run the engine and use a length of pipe like a stethoscope on the cam cover and see if you can hear the offending lifters?

Cam bearing caps should be Ok if you are careful to put them back in the same locations and the same orientations as they came out and ensure the mating faces and bearing surfaces remain spotlessly clean.

Doing one cam at a time is probably advisable.

Not sure about checking lifters. I replaced the whole set as I was completely overhauling the engine.

I'm sure someone will be along with some advice.

Should be treading a similar route tomorrow fitting ClarCE's 3.0 cams!

Kevin

[jonny2112]

Covers are off as I have a cambelt problem and the engine is stripped down to this point ready for replacement belt. As the belt would have to be done anyway if removing the cams, and because I have leaky cam cover gaskets, I thought I would try and do it all at once, though I thought it may be easier to detect an offending lifter.
Financially I couldn't afford to change them all, as ClarCE also discussed in relation to his cams, particularly as there is so much else to be done as well.

[Marks DTM Calib]

On every lifter I have worked on from an Ecotec power plant, the plunger can be pressed and springs back even when empty.....those that dont have been binned and replaced with ones that do....is the plunger on the new ones visably out....as they might be supplied with oil already in them (which would make sense in production)....

The checking procedure described does two main things

1) It allows you to determine if any of teh small internal springs have failed, these also press onto the ball bearing that seals the lifter.

2) You basicaly get a nice empty lifter that no longer has any 10 year old oil in it....or grit etc....so when the engien is re-started it will clack like buggery for 10 mins or so....but, the lifters will fill up with nice fresh oil (assuming you put nice fresh oil in it!)

[Marks DTM Calib]

As for changing them all......Every one I have looked at has had pretty much zero wear markings on them, even at well over 100K miles....you can even see the original honing marks!

Hence I dont change them unless there is something wrong with them.....and hence the test method I adopt and the close visual inspection....

[jonny2112]

On the new lifters the plunger is definately in and won't depress any further. This concerns me as I wonder if they are not as they should be?
From a practical and experience point of view I am tempted to take the old ones out to compare them, clean them as described and simply replace them. Perhaps the cleaning in itself will help the tapping noise, and if there is something really obvious I can deal with it.

[Marks DTM Calib]

That would certainly be my advice....and approach

Also, pop the T vents out and clean them (the torx headed plugs in the cam areas of the head...2 off, 1 per head)

[jonny2112]

Thanks Mark. Started to turn the crank to set the locking tool to remove the cam sprockets but it won't turn any more than about 60 deg. Is this anything to do with the cam cover being off or something more sinister? I was able to move it right round on Thurs to check the timing marks.

[jonny2112]

The cam sprockets have actually gone through about 90 degrees. The crank will turn but springs back to its current position. Wondering too if its because of the slack in the belt.

[jonny2112]

D'oh   Sorted.
In pushing the car back to gain access to the garage one of my kids was driver and pulled on the handbrake for me. I didn't realise the car was now in gear!  

[jonny2112]

Ok. Checked all the lifters and as M DTM says there is nothing obviously untoward, and they look exactly as the new one, ie closed.

http://i91.photobucket.com/albums/k295/jonny2112/car004.jpg

What do you think?

[Marks DTM Calib]

That looks open to me......have you cleaned them out by forcing the centre plunger in....what was the oil like that came out...

The lip on the centre plunger goes in as far as the outer sleeve in which it sits......

[jonny2112]

That looks open to me......have you cleaned them out by forcing the centre plunger in....what was the oil like that came out...

The lip on the centre plunger goes in as far as the outer sleeve in which it sits......

I was just looking at that outer sleeve. It doesn't depress with some pressure but I'll try a vice to see...