The ultimate tappet thread

[Ben Lessani]

Hey ho troops. My car is bugging me again, the tappets have been noisy on and off for the past 2 years, they've been progressively getting worse as time has gone on.

I stripped them off the car at the weekend, numbered them, degreased them, cleaned thoroughly in thinners and bathed in oil for 20 mins. Before the clean, the plunger was rock solid, no movement whatsoever. After cleaning them up (no broken springs), they were just like new units, plently of rebound. When squeezed with oil in, it shot out the little hole with no problems.

I put them back in to the car, the cam was torqued properly, and set about building up the belts and rocker. I started the car, have run it up to temperature (tappets VERY loud), hit 80-100 degs oil temp and brought the revs up to 3.5-4000 RPM on an M'Way to get the oil pressure up to max.

I calmed it and brought the car back in under 2k, been driving over the space of 1 hr and just parked up.

The tappets are louder than ever before, so loud it sounds worse than a Ford push rod piece of s**t. Oil was Forté flushed and changed 600 miles ago with genuine VW filter.

Its either low oil pressure in the head (blocked channels, bad pump) - if so, is there any way of testing it? Is the amount of oil normal in the pic below if the car was stationary for 12 hrs.

Or the tappets are well and truly finished, even after a refurb (which I find hard to believe).

I've never had the oil pressure warning light on, nor the buzzer. My step dad does have an Audi coupé - so I might pinch his oil pressure gauge to quickly test my own.

What's going on

[Diamond Hell]

Although they may seem fine, it's possible that they are knackered and that you're not seeing that when they're cold.

Why don't you just replace them, if you're keeping the engine, that is....

[Ben Lessani]

I have no quarms replacing them, hardly big money. Its just that I thought I may as well give refurbing a try - most folk tend to have a good success rate considering there is very little to go wrong on them.

No reccomended diagnostic checks to make sure oil is getting to the tappets?

DH, the engine stays, for now

[DarnPB]

I would replace them if I were you. They may have been cleaned and I take my hat off to you for giving it a go.  (Just read your projects thread.) But they are old items and they don't last forever.
One more thing you can try, if you have the balls. Start the engine and bring up to temperature. Then rev it to peak revs and hold it there for about 3 seconds. This may force the oil in into the tappets. (I have had a little success doing this with aircraft piston engines and car engines alike.) But try it once and no more, otherwise you can damage the cam!

TBH though, the tappets are either shot or you have fitted the spring in the wrong position during re-assembly are not hydraulic locking as they should.


I hope you did not use a magnet to extract them from their bores! That WILL knacker them straight away.

[Ben Lessani]

i filled my magnetic parts tray with degreaser and chucked all the little bits in it, i let them sit for a little while whilst i started banging the next tappet.

 :embarassed: :embarassed: :embarassed: I think I killed them then. I'm a spaz sometimes.

I didn't think it was possible to fit the spring in the wrong position, there's only one way for it to go in. eBay tappets it is then, I'll drive round with these rattley cam killing buggers for the next 48 hrs, if it allieviates, I'm all set, if not, new tappets.

[DarnPB]

Yup, ther're knackered then. If you use a magnet, it magnetises the tappet and the ball bearing, although spring loaded against its seat, will be held off its seat magnetically. You can get them de-goused, but TBH, it's not worth it. Now you know what the trouble is, don't try the high rev method!

[Ben Lessani]

Darn it. Well that means that I'll have to do the stem seals whilst I'm at it, so I'll buy all the tools and bits and set about it this weekend.

How much do lairy cams go for these days

[Mew]

I'd try and spend as little as possible on the engine if you plan to go 16v soon. I very nearly chucked in a 2.0 bottom end, kent cam and tsr manifold onto mine, but knew a 16v would go in anyway so just waited a bit, rather than waste the time/effort/money. I then managed to get a complete car for £150, cost me £140 to get it back to Oxford. I then sold most parts and made my money back, still have a set of 15" RAs and also a 2.0 16v engine.

There's a little bit of encouragement

[Ben Lessani]

I'm taking the cam off again - I'm going the risky route and clamping the timing belt for speed.

If the bits are magnetised, I'll replace the ball bearings with some of my spares and see if I can get the plunger to lock. I'm determined to make them work.

Never say die!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

If you magnetize something yourself, usually you can whack it with a hammer to randomize the dipoles or do the same with a butane torch since heat will randomize the dipoles.

Will my magnets demagnetize if I heat them?

Yes, if you heat them beyond 170 degrees Fahrenheit (80 degrees Celsius) the magnets will quickly loose their magnetic properties. Sustaining these temperatures for a length of time or heating the magnet significantly higher than this will permanently demagnetize it.  Other types of magnets such as Samarium-Cobalt have higher heat resistance.

[DarnPB]

I'm taking the cam off again - I'm going the risky route and clamping the timing belt for speed.

If the bits are magnetised, I'll replace the ball bearings with some of my spares and see if I can get the plunger to lock. I'm determined to make them work.

Never say die!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

If you magnetize something yourself, usually you can whack it with a hammer to randomize the dipoles or do the same with a butane torch since heat will randomize the dipoles.

Will my magnets demagnetize if I heat them?

Yes, if you heat them beyond 170 degrees Fahrenheit (80 degrees Celsius) the magnets will quickly loose their magnetic properties. Sustaining these temperatures for a length of time or heating the magnet significantly higher than this will permanently demagnetize it.  Other types of magnets such as Samarium-Cobalt have higher heat resistance.

If you whack them with a hammer, you will damage them.

If you heat them up, you will also alter their hardness values.

Its not just the balls that are affected. Its the whole unit. GSF do tappets and they are not dear, so do the job once and do it properly. You will only be taking the engine apart again.

I once found metal in the oil filter of an aircraft piston engine, so I decided to look further. Everything checked out OK, so I went for the tappets. I found one with a magnet stuck inside it. The magnet was from one of those telescopic magnetic pick up sticks. Anyway, this caused the destruction of the cam shaft. The result was that I had to remove the engine from service and send it for overhaul, at the cost of 12k.
The report came back from the overhaulers that the iron filings from the camshaft had taken out the big end and the main end bearings as well as the oil pump. As a result, the propellor was also sent for a check over as a precautionary measure. Thankfully, that was ok.

Fit new tappets!