Supragal Posted August 2, 2006 Share Posted August 2, 2006 Ok, so as most of you know my cars not run properly since I got it back from it's ordeal at the bodyshops, anyway we've diagnosed a stuck valve on cylinder 4. It's proper stuck, and stuck down really quite a way. I am trying to avoid taking the head out if I can help it but will do if necessary. I think the chances of it being bent are very low as it has just been sat there doing nothing so chances are it's just gooed up. Tomorrow night we are going to try the rope trick to push it back up and also oiling the valve stem. Any other suggestions as to how we might get this sorted? Also, what are the chances that there is corrosion or something causing the block, obviously I don't want to stuff the engine. All the other valves are fine, they push down by hand and return perfectly. Just this one. Any thoughts/comments/experiences greatly appreciated! Thanks to everyone so far too- Ian C Scooby Homer Laz & Katie Simon B etc. Link to comment Share on other sites More sharing options...
TLicense Posted August 2, 2006 Share Posted August 2, 2006 It's a non interferance engine Rosie, so it shouldn't be bent, unless something has got in there to bend it, but then you'd have known about it. Give what you've got in mind a try, it'll probably "pop" up when you raise the piston and give it a nudge. If that doesn't work it's either borescope or head off time. Link to comment Share on other sites More sharing options...
Supragal Posted August 2, 2006 Author Share Posted August 2, 2006 borsecope? is that what it sounds like? as in let me see in to see what it sticking it? Link to comment Share on other sites More sharing options...
uk-rich Posted August 2, 2006 Share Posted August 2, 2006 i would give it lots of oil, then if still tight, more oil Link to comment Share on other sites More sharing options...
Digsy Posted August 2, 2006 Share Posted August 2, 2006 i would give it lots of oil, then if still tight, more oil YOu can't get at the valve stem unless you take the seal out, though, which means camshaft out, tappet out and spring out. I'd be very careful with the rope trick. Trying to force the valve up by pushing it up with the piston might work but if you force it then you stans a very good chance of bending the stem, and then the head will have to come off. I'd have a VERY gentle go with the rope, but then take the camshaft out and investigate further. If the head has to come off the cams will have to come out anyway, so its a stap along the same road, if you see what I mean. Link to comment Share on other sites More sharing options...
Supragal Posted August 2, 2006 Author Share Posted August 2, 2006 Camshaft is already out Digsy. I don't really want to go down the £400 route of replacing all the head bolts/ gaskets/ seals etc if I can help it for a start. Well, not at the mo and it'll drive me nuts if I have to wait any longer! The bending thing is waht bothers me, was hoping someone might suggest a way that we can apply pressure flat instead of at an angle Link to comment Share on other sites More sharing options...
Digsy Posted August 2, 2006 Share Posted August 2, 2006 I see. Is the spring and retainer still on the valve, then? I'm just wondering whether it might be safer to try to tap the valve downwards a bit more to free it. I'm guessing its stuck at maximum lift. You could use a bit of wire down the spark plug bore to set the piston just below the valve head to stop it dropping into the cylinder if it pops free, then pull it back up with some pliers. Link to comment Share on other sites More sharing options...
Miguel Posted August 2, 2006 Share Posted August 2, 2006 I would Be VERY VERY careful with the rope trick if the valve is already down as the chances of the rope getting caught behind the valve and bending it are very high now unless you are ubber careful and have the inlet manifold off so you can keep an eye on the rope not getting trapped behind the valve. I would be having the bucket on that valve out ( with a strong magnet) to see if its gummed and then very gently tapping the stem of the valve downwards with a soft drift and hammer to see if the shock and tension of the spring will pull it back up. If that doesnt do it I would be having the inlet off just to see if the stem is gummed or IF its allready gone the gay way. Edited: Digsy beat me to it! Link to comment Share on other sites More sharing options...
Mike M Posted August 2, 2006 Share Posted August 2, 2006 Cant you give the valve stem a gentle tap with the spring and retainer in place so it moves just enough to break free before removing the retainer and spring. Ahh wait, that wont work if the valve spring is fully compressed already. Edited to say, migster beat me to it Link to comment Share on other sites More sharing options...
Digsy Posted August 2, 2006 Share Posted August 2, 2006 It might work. Even if the valve is at max lift there will still be some free play in the spring. Link to comment Share on other sites More sharing options...
Supragal Posted August 2, 2006 Author Share Posted August 2, 2006 Sorry I should have said. we have already tried to free it by 'tapping' it and the bucket thing is out, although that was a joke in itself. We fashioned a magnet from the door speaker and socket piece but every single time it got level with the top it just dropped back again. We were there ages- not funny! Got it eventually. The 'tapping' resulted in the valve compressing more so we don't want to push it too far. It certainly hasn't inclined it to move itself upwards at all. We are going to check where the piston is sitting tomorrow and if theres room we'll try it again. I'm only guessing but I don't think the spring has much further to compress. It's bloomin difficult to get something suitable and non marking to tap it with though as it just slips and probably has little effect. Link to comment Share on other sites More sharing options...
Miguel Posted August 2, 2006 Share Posted August 2, 2006 Are both cams out?? just be carefull that either the other cam is out or the lobes on the same cylinder are facing upwards. They can touch if you push them down too far ( ie overlift) Link to comment Share on other sites More sharing options...
Mike M Posted August 2, 2006 Share Posted August 2, 2006 sounds like it's quite well stuck, is there no way of letting it soak overnight with WD or plus gas then having another go. Sounds like the stem has dried out, i dont know what material the valves are made of but it maybe has a layer of rust on it. Link to comment Share on other sites More sharing options...
Supragal Posted August 3, 2006 Author Share Posted August 3, 2006 Good point mig. I'll keep an eye on that. Rust. I haev asked a resident expert and I was under the impression that that was a definate no no. Link to comment Share on other sites More sharing options...
Digsy Posted August 3, 2006 Share Posted August 3, 2006 Valve stem seals are usually hard chrome plated to resist wear. Of course if something gets lodged in there you might scratch through it. If you compress the spring until it goes solid you won't be able to get the valve collets off. I'd buy a spring compressor and whip the spring out now. Link to comment Share on other sites More sharing options...
b_have Posted August 3, 2006 Share Posted August 3, 2006 Head off is the only option IMO, If the valve hasn't popped back after a gentle tap it needs to be investigated. Almost certain guide/stem damage. Link to comment Share on other sites More sharing options...
Supragal Posted August 3, 2006 Author Share Posted August 3, 2006 Valve stem seals are usually hard chrome plated to resist wear. Of course if something gets lodged in there you might scratch through it. If you compress the spring until it goes solid you won't be able to get the valve collets off. I'd buy a spring compressor and whip the spring out now. Ian is generously sending his... Link to comment Share on other sites More sharing options...
Supragal Posted August 3, 2006 Author Share Posted August 3, 2006 Head off is the only option IMO' date=' If the valve hasn't popped back after a gentle tap it needs to be investigated. Almost certain guide/stem damage.[/quote'] What things could cause damage? Dried out? Seems odd that 1 out of 24 has dried out but I suppose possible if it was down when last left and it's drained. Link to comment Share on other sites More sharing options...
b_have Posted August 3, 2006 Share Posted August 3, 2006 Sabotage (sp)? Link to comment Share on other sites More sharing options...
Ian C Posted August 3, 2006 Share Posted August 3, 2006 I seriously doubt it's sabotage, way too subtle and difficult for the fuckwits who had it. The tapping was done without a load of lube in place. I'm thinking shedloads of oil and leaving it to soak, maybe WD40 to start with to penetrate, and some normal fresh engine oil on top. Then pull the retainer and spring and see if a bit of jiggling will loosen the thing up. Or even tap it in a bit further without the spring in place (piston up to avoid it dropping in too far!) I thought pliers on a valve stem is a no-no as scratching the stem can cause a fatigue fracture start point? -Ian Link to comment Share on other sites More sharing options...
Supragal Posted August 3, 2006 Author Share Posted August 3, 2006 Sabotage- maybe but I'd have thought the bolts would have come off easier if they had been freed recently. Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 3, 2006 Share Posted August 3, 2006 Sounds like a bent valve to me. Link to comment Share on other sites More sharing options...
TLicense Posted August 3, 2006 Share Posted August 3, 2006 The tapping was done without a load of lube in place. I'm thinking shedloads of oil and leaving it to soak, maybe WD40 to start with to penetrate, and some normal fresh engine oil on top. Then pull the retainer and spring and see if a bit of jiggling will loosen the thing up. Or even tap it in a bit further without the spring in place (piston up to avoid it dropping in too far!) I thought pliers on a valve stem is a no-no as scratching the stem can cause a fatigue fracture start point? -Ian Remember the valve is down. Any lube you put in there is going directly into the cylinder, and I'm not sure if WD40 is what you want in there. Rosie, it's going to be either a stuck valve, or it's bent. If it's stuck the rope trick *should* free it if your careful with it. If it's bent, then it's bent/damaged and won't pop up with gentle persuasion then the head's going to have to come off anyway so you've got nothing to loose. Link to comment Share on other sites More sharing options...
Supragal Posted August 3, 2006 Author Share Posted August 3, 2006 OK, so it's up! Gentle tapping has released it up but it's still not smooth like the others so we've doused it in oil and WD and see how it is tomorrow. Still good news- if it's up then it can't be bent Some before and after. http://img182.imageshack.us/img182/986/dsc03300gw0.jpg http://img523.imageshack.us/img523/7208/dsc03303uy7.jpg http://img182.imageshack.us/img182/2843/dsc03304ld8.jpg Link to comment Share on other sites More sharing options...
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