Sticking Valves

ChemCool · Post by **ChemCool** » Tue Oct 30, 2007 2:15 pm

Is that correctly stated? Is there something like that?
Tell me more please- any one out there? Noises, causes? Reasons etc.
Thanks

Gary57 · Post by **Gary57** » Tue Oct 30, 2007 2:25 pm

A sticky valve will cause the motor to miss on that cylinder.

Vlade · Post by **Vlade** » Tue Oct 30, 2007 2:33 pm

don't really think the CA18 can have sticky valves... if one think of the mechanics behind it, cam forces lifter down, lifter compresses valve spring forcing valve out...

although the lifter acts as a cushion it will still force the valve out, but if the lifter is totally fucked that it collapsed on it self it might cause a sticky valve, but even F'd up lifters like Ero's old CA18 had will still push the valves out.

I've seen sticky valves on opel corsa's but they runrockers, if the rocker falls off/breaks, the valve "sticks"

Draco · Post by **Draco** » Tue Oct 30, 2007 3:23 pm

Vlade wrote:don't really think the CA18 can have sticky valves... if one think of the mechanics behind it, cam forces lifter down, lifter compresses valve spring forcing valve out...

although the lifter acts as a cushion it will still force the valve out, but if the lifter is totally fucked that it collapsed on it self it might cause a sticky valve, but even F'd up lifters like Ero's old CA18 had will still push the valves out.

I've seen sticky valves on opel corsa's but they runrockers, if the rocker falls off/breaks, the valve "sticks"

Just a silly question because I don't know, as you say Vlade all you discribe pushes the valve out....what brings it back too seal the chamber and might that not be the problem....that some of the valves stay open a bit....?

veecee · Post by **veecee** » Tue Oct 30, 2007 3:29 pm

Draco wrote:
Vlade wrote:don't really think the CA18 can have sticky valves... if one think of the mechanics behind it, cam forces lifter down, lifter compresses valve spring forcing valve out...

although the lifter acts as a cushion it will still force the valve out, but if the lifter is totally fucked that it collapsed on it self it might cause a sticky valve, but even F'd up lifters like Ero's old CA18 had will still push the valves out.

I've seen sticky valves on opel corsa's but they runrockers, if the rocker falls off/breaks, the valve "sticks"
Just a silly question because I don't know, as you say Vlade all you discribe pushes the valve out....what brings it back too seal the chamber and might that not be the problem....that some of the valves stay open a bit....?

the valve springs bring the valve back to its original position broo. i think vlade means that because its a cam lobe on valve design, and a lobe per valve design, even a collapsed lifter wouldn't cause a sticky valve???

hmmm, or something like that?

Draco · Post by **Draco** » Tue Oct 30, 2007 3:36 pm

I got what vlade sayd,what presisely am I asking....what if the spring is broken or somehow not able to bring the valve back into position to seal properly?

Get what I am asking?

veecee · Post by **veecee** » Tue Oct 30, 2007 3:41 pm

could be...

but i think in that situation, there would be some telltale noises coming from the valvetrain, and the valve/piston interface!!!

there would also be horrible missfiring i reckon, but the noises would be prominent PROBABLY!

Draco · Post by **Draco** » Tue Oct 30, 2007 3:50 pm

And that dear watson is why I ask....he is hearing knocking noises...

veecee · Post by **veecee** » Tue Oct 30, 2007 3:57 pm

he's gonna be upset if he has to open that head up again!!!!

but what kind of noises are they, where are they coming from?

any reason to suspect they come from the head?

Draco · Post by **Draco** » Tue Oct 30, 2007 4:01 pm

Don't know presisely but he said he is hearing noises, I was just wondering if that might be something to look at....more than that, I don't know

Ero_sennin · Post by **Ero_sennin** » Tue Oct 30, 2007 4:10 pm

Draco wrote:Don't know presisely but he said he is hearing noises, I was just wondering if that might be something to look at....more than that, I don't know

hearing noises? I used to hear noises and voices. Freddie when did yours start?

widowmaker · Post by **widowmaker** » Tue Oct 30, 2007 4:13 pm

a nice tip that helped me sort a sound on my bike is to take a screw driver with a hard plastic handle and put it against the engine in various places and the plastic part on your ear. you will hear where the sound is the loudest.

works lekker

veecee · Post by **veecee** » Tue Oct 30, 2007 4:22 pm

widowmaker wrote:a nice tip that helped me sort a sound on my bike is to take a screw driver with a hard plastic handle and put it against the engine in various places and the plastic part on your ear. you will hear where the sound is the loudest.

works lekker

surprisingly, this is an extremely helpful hint!!!

i was half expecting widow to make comments about his own personal sticky valves

anyway, a screwdriver in the ear can be a very effective tool!!!!!

Vlade · Post by **Vlade** » Tue Oct 30, 2007 4:27 pm

no the noise sounds like a knock, but in a sense it sounds to me like pre-ignition, like then the timing is way too advanced

this is only when you come off the throttle, if its not that its a big-end

Charl · Post by **Charl** » Tue Oct 30, 2007 7:27 pm

widowmaker wrote:a nice tip that helped me sort a sound on my bike is to take a screw driver with a hard plastic handle and put it against the engine in various places and the plastic part on your ear. you will hear where the sound is the loudest.

works lekker

I bet you he had it the wrong way round and the bike was thinking what the fu%* is wrong with this okes head