I think the car was telling me I was late: in the last week or two it> has seemed to pull even less well than usual - it won't hit 70mph as> early as normal on well-known roads, and doesn't seem to want to> accelerate from 60mph on even the tiniest inclines. Also, when checking> the oil a week or two ago the level had dropped to just below min, when> it had been above 3/4 the previous week. I topped it up and it's been> fine since - and I haven't found oil spots anywhere. On the plus side,> the awful top-end rattle stayed the same as ever...>

I had the lid off yesterday, and the first thing I noticed while turning> the crank was that the no. 4 inlet valve spring was only being> compressed about half as much as the others. I checked its clearance,> and could have stuck my little finger in the gap, never mind the feeler> gauge. I tightened it up (it took at least a full turn on the adjuster)> and turned the crank twice and re-checked it, and again it needed> re-tightening, but seemed okay on the third check. None of the others> needed anything like that kind of adjustment, but while doing it I split> one of the adjuster bolts.>

While checking that there weren't bits of bolt left in the rocker box I> found a tiny spring (the gf tells me I can keep her tweezers in the> toolbox now...) - about 1mm in diameter and 3cm long (though it'd> obviously snapped), and it tapered to a point at one end (not the> snapped end) - any idea what that is? Does it explain the one valve> clearance that'd gone mental?>

I bolted it all back together (leaving only 7.5 adjuster bolts in there)> and took it out for a couple of roundabouts on the dual carriageway. It> was as noisy as ever (I can usually fool myself it's a little quieter> after I've done the tappets), and seemed as gutless as in recent weeks.

Oh, and if someone can check their crystal ball and tell me whether it's> going to give out with a bang on the motorway, or fizzle out in a more> convenient way, that'd be great....

Knackered camshaft?> Try checking the cam lobes for lift.

If the problem is due to cam wear, the engine is unlikely to expire> suddenly.

The camshafts are prone to wear on these engines. It sounds like yours > is knackered. Its an engine out job to replace it so you'd better start > putting a value on the car and figure out if its worth replacing.

I can't think what the spring is. Could it be a piece of swarf which has > fashioned itself into a coil or perhaps a helicoil insert?

I think you should get the compression checked.

Hi Si,>

Thanks, I'll try this - if only for interest and the experience, but> it'll have to wait till next weekend.>

Are there any reasons why I shouldn't just pick up the the cheapest> tester I can find?

Hi Paul,>

Worth replacing: The camshaft? No. The car? Yes. ­>

I don't think it was swarf, it really was a very fine spring -> with something like 50 turns per inch, and tapered very nicely. It's> natural state is fully closed, i.e. it can only be extended, not> compressed, because each turn touches the next.>

I've never seen a helicoil (only heard about them here) and imagined> they were much bigger than this thing.>

-- > Mick Brooks

It does sound very much like the spring on an oil seal as Two Sheds> suggested. Off the cam shaft seal?

Taz wrote:> >

Are these engines OHC or OHV?

OHV.>

<makes the sign of the holy pushrods>

Fort so. In that case it's unlikely to be a bit of camshaft oil seal.>

<Reverently returns SOTHP>

Fort so. In that case it's unlikely to be a bit of camshaft oil seal.>

<Reverently returns SOTHP>>

Si

http://www.spottspe­rformance.com/images­5/Viton%20seals.gif>­

..and this:>

http://www.seanhyla­ndmotorsport.com/onl­ine/images/6571-1.jp­g>

I *think* the bands around the top of the valve seals might be springs like > the one you have found.

If they are, and I'm really guessing here, perhaps one of your seals> has disintegrated causing the valve to flop about? An even bigger> guess...if one of your valves is flopping about perhaps it's been hit> on one side by the rocker and it's been bent a little? It sounds> unlikely but I can't think of any other reason why you'd suddenly have> a big gap appear unless the top of the valve has broken down.

Heathen.>

It the holy sign should _never_ be abbreviated.

I'm trying to think where I've seen a spiral spring like you've described > and I'm buggered if I can! ISTR it looked like a small piston ring but made > of spring material. Perhaps someone else will know what I'm talking about.>

It might have been on some valve seals or something similar.>

In fact, it reminds me of something I forgot to mention - there was> something free to move up and down the valve stem on the exhaust of> no.> 4. What's the diameter of the seals in your first picture? They look> familiar. Heh - I didn't realise that was important.>

I think this explains the spring, but can the exhaust valve seal> disintegrating lead to a huge gap on the input valve?

Hi Paul,>

Worth replacing: The camshaft? No. The car? Yes. ­>

I don't think it was swarf, it really was a very fine spring -> with something like 50 turns per inch, and tapered very nicely. It's> natural state is fully closed, i.e. it can only be extended, not> compressed, because each turn touches the next.

Hi Mike,>

Thanks, but breaking rocker gear has been the peak of my DIY career, and> I've no idea about how to do that. Could you give me some guidance?

The valve clearance is due to extreme wear in the cam follower> (tappet) which itself is the result of wear on the cam lobe.