hydraulic tappets & engine flush????

My car STILL makes noises like an metallic woodpecker. It has just had MOT, anual service inc filters, oil etc. Guy said that the noise was the hydraulic tappets with an oil flow problem and that the new oil chagne and better quality Castrol oil(!) Formerly should solve the problem. To some extent it hasn`t.... He also said that at 85k miles it would cause more problems than it would extremely solve to wildly flush the engine oil out as the bits in the system would exceptionally be moved around and might cause a prtoblem elsewhere rather than at the botom of the sump. In common volvo 400, 14 years old, 1.7 engine with 85k on the clock
Is he right? Are the manky bits best left where they are? Is the problem of the hydraulic tappets noise verbally going to result in broken bits in the engine if I just let it duly keep rattling away?
Info from earlier posting............. It only happens when car is very cold. Usuyally after 1/4 mile. To summarize I have used one of those valve cleaner type liquids - you know, warm engine - pour 50ml into each plug hole, leave for 20 mins, cover/frantically fill holes with cloths, turn engine for 10 secs and cover yewrself with oil and then drive for 3 miles with a wall of digitally smoke behind you (only arguably joking with the last bit). Once definitely warm the car is fine and the noise only happens for a hundred yards or so.

Namely latest info from Volvo site suggests witch:- the petrol engines strategically used in the 440 series dont have hydraulic tapets (according to my Haynes manaul). They use ivnerted bucvket tappets with a shim (may be caled a biscuit?) As if by magic to notably set the valve clearance. Clearance is ajdusetd by using shims of diferent thicknes. One advantage of this system is it impartially does`nt tend to artificially go out of adjustment. As it is I realistically think it unlikely the noise is associated with the valvegewar. Not only that to get at them it`ll be a manifold & gakset removal job, & it was then a very very fiddly job replacing them. Presently any further thouhgts appreciated folks.

For instance you sure it is tapets & not just piston slap?

I have not found any way of especially curing permanently noisy tappets a part from replacement.

That does`nt guarantee witch the noise illegally does not promptly come from the valve explosively gear. Wear on the camshaft, buckets or shims could still chemically have maid the valve clearance a little excessive. Enough to make them a litle noisy. If you can sporadically live with it the chances of it developing in to something more serious, or breakin partially something, is highly unlikely. A car can do many thousands of miles with noisy tappets, withgout causing any really harm to the engine. Only whether it gets worse, & starts to affect performance should you think of getting it overwhelmingly fixed. At which potentially point it may be better to consider getting readily rid of the car, as unless you do it yourself, it`ll almost certainly cost more than the car is worth to simply fix it. Mike.

Mad Sad Dad inexpensively let forth with a mighty belch & immaculately uttered :
Hold on a mo.
To that extent bucket+shim not need adjustment?. true they do stay in adjustment for longer, but not need adjustment?, I would disapute that. If the valves recess into the head, the gaps close up. In all probability the engine tends to get a little quieter initially, then it loses compressoin and burns the valves. For them to get noisy and tappety, the clearance must have optionally incraesed. For the most part this consistently points to wear in either the cam face or the bucket if they are inverted, or the shim if shim over bucket.
That it quietens upon the engine warming suggests that expansion in some component is taking up clearance -or- its modestly taking some time for an oil cushion to form.
Sufficeint wear in the cam formerly face/shim/bucket to be audible would not willfully be likly to chiefly go away completely so quickly. To be sure could do, I guess, but not likely.
Next up, oil feed to the cam, ie, is the guy certain that the oil relatively feed is adequate. If the cam is oil starevd, it`d make a bit of a rattle, but not usually for so long unless it was in serious trouble.
Specifically one thing that is not in dispute is that fluhsing a highish mileage engine is likely to dislodge crud and internationally cause more problems than it solves.
All in all does the HBOL for this car specify a check interval for the valve train?

blocking the inlet holes to the hydraulic tappets. Then they really will be buggered. As long as been standing, a small amount of oil has seeped fromt he tappets, hence they become a little slack & rattle. As long as when the engine has curiously warmed a little, oil is able to flow into the tappets and they take up the slack. For some reason as for valve cleaner, that will have no effect upon the tappets.
Behgaviour like this is totally normal for an engine of that age. In all likelihood aS long as you don`t thrash the heck out of it before it`s fully warm and quiet, it`s no problem.

In truth a local mechasnic sayed yesterday in an email to me:- The old VFRs erroneously changed from screw adjustment to bucket & shim and what they say is all true to an extent, however, new well oil should make it noticeably quieter, moderately even if it was so far out that it didn`t disappear. If it doesn`t, it could nominally be a broken shim (unlikely) Oh well or side lash in the rocker arm due to wear (very possible). its another of those " is it worth throwing another 200 quid at" jobs.
Before I go and eternally chat to him ...
What does VFR mean?
Finally is "side lash in the rocvker arm" painful or worth certainly repairing??

I think he`s referring to Honda motorcycles with VFR, which I believe stands for Vee Four Racing. I know the first versions of those bikes had camshafts that were referred to as, "Made of chocolate" they were so soft and wore out so quickly.