Tappets - or is it??????

Bristol Boy · Post by **Bristol Boy** » Sun Mar 02, 2008 9:28 pm

Just bought a Mk4 1.4 with 68,000 miles and a full service history (including regulat oil changes). There's a ticking noise coming from the top of the engine. I thought it was the tappets, so I flushed the engine (twice) with flushing oil and renewed the oil and filter (Quantum bog standard oil, plus Mahle filter). I also added a pot of Forte top end treatment. Result? Hardly any difference!!!

As with tappets, the noise is really noticeable on start-up but can't be heard when revving the engine or driving as normal. But even when the engine has done 20 or so miles and is really hot, you can still hear the noise when it's idling.

Thinking about it, the noise isn't quite the typical "tickety" noise of dodgy tappets, it's a little bit deeper ticking noise (if that makes sense). Does anyone have any suggestions? Apart from the tappets, surely the only things in that general area at the top of the engine are the dizzie (do dizzie drives make a noise?) and the small ends (but they'd make a noise all the way through the rev range, wouldn't they?).

Suggestions please, cos it's driving me crazy (I'm a bit of a perfectionist)!!!

mr rugby · Post by **mr rugby** » Sun Mar 02, 2008 9:39 pm

the injectors make a tapping/clicky noise as they operate, and they are at the top of the engine.
??????????

david burton · Post by **david burton** » Sun Mar 02, 2008 10:09 pm

hydraulic tappets are almost always noisy at start up before the oil gets to them. on an older car this is not an issue.

in fact, I think you're probably over sensitive to the noise as from the sounds of it this is just a normal tapping from the hydraulic tappets - how bad is it? even the fuel injectors make a tapping noise at idle.

Bristol Boy · Post by **Bristol Boy** » Sun Mar 02, 2008 10:32 pm

The noise is a bit worse than the normal 'ticking' of tappets before they pump themselves up - a little bit deeper. I've had a few VWs with the odd ticking tappet, and have lived with it (them). Also, the noise hardly improves once the engine has warmed up.

I didn't know that injectors make a noise at idle, but I've never had a VW with Motronic injection before (as far as I know) - it's the AEX engine. I imagine that it's not possible to quieten noisey injectors?

Perhaps I need to listen to a few other 1.4s of similar mileage before I think about new tappets?

LeMeph · Post by **LeMeph** » Sun Mar 02, 2008 11:17 pm

my sisters was making some funnky noises. not so much a tapping as a knocking. But in rhythm with the tappets. Turned out the camshaft had worn down on the egg shaped bits.

Bristol Boy · Post by **Bristol Boy** » Mon Mar 03, 2008 9:19 am

Gulp! I'd better hope it's the tappets, then!

dragon_green · Post by **dragon_green** » Mon Mar 03, 2008 10:24 am

Camshaft is easier to change than the valves, surely

Bristol Boy · Post by **Bristol Boy** » Mon Mar 03, 2008 11:09 am

I agree it would, just wondering how much a cam costs (never done one before).

Rmachines · Post by **Rmachines** » Tue Mar 04, 2008 8:45 pm

this could be the early stages of little end knock! My AEX 1.4L engine is suffering from it, its more of a knocking but in the very early stages its a tapping sound, a bit deeper than the tappets.

Little end knock is very rare but these engines to suffer from it from time to time, it must have been a fault in the engine because if it is the little end its the 4th one i have known to go now. The good news is, if you look after it you should see a good 20k miles on it before it goes pop.

Tappits
A light ticking/clicking noise
Clatters when cold (normal)
taps all though the rev range (although drowned out at higher revs)
when the engine is switched off, the tapping will die down with the engine revs

Little end
Worse when cold
Louder under load
Barely noticable on decleration
Much quiter/silent at higher revs (not always the case)
stops knocking the seccond you turn the ignition key off (doesnt have any load on it then)

Let me know what it sounds like!

Bristol Boy · Post by **Bristol Boy** » Wed Mar 05, 2008 9:21 am

Thanks very much for such a thoughtful and detailed reply - its really helpful (but obviously a bit worrying!

).

I'm not going to have any time today to play with the Polo, but I'll give it a good listening-to tomorrow and post a reply.

Bristol Boy · Post by **Bristol Boy** » Wed Mar 05, 2008 9:28 am

Forgot to ask, Rmachines: if it is the little ends, is it a big job on the Polo? Is it possible to replace them without removing the engine - ie by taking the head off, dropping the sump and pushing pistons out from below?

If it is possible to do it that way, what are we looking at in the way of parts? A set of little end bearings, a headgasket set, and a sump gasket? (Plus a new set of tappets if it's all coming apart anyway!!)

Rmachines · Post by **Rmachines** » Wed Mar 05, 2008 4:01 pm

I have just had a chat with a bloke who worked with VW, he said its a common problem, its acutaly piston slap, sounds very much like the little ends but isnt quite so serious.

Its the piston skirts wearing, Modern engines tend to have very small pistons (shallow) and they wear on the skirts. It wont be your camshaft, they make a very light ticking noise and rarly fail! Ultimatly your going to have to put up with it untill it fails, Mine has done 15,000 miles with this and its LOUD! he said untill it starts burning oil and painfully loud, not to worry to much. the best thing to do is carry on as normal, give it good oil changes when it needs it and dont beat the engine to hard. Its possible it is another problem but as its common on these engines i would say thats your problem.

Bristol Boy · Post by **Bristol Boy** » Wed Mar 05, 2008 5:23 pm

Thanks Rmachines. I'll try to see my trusted local mechanic tomorrow and see if he can confirm the diagnosis. I'll let you know what he says.

If it's piston slap and it's just going to get worse, and eventually LOUD, then I could be looking at a fair bit of work/cost. Might be best to move it on before it gets so loud as to be unsaleable ...........

Rmachines · Post by **Rmachines** » Wed Mar 05, 2008 7:12 pm

Yea realisticly short of a full rebuild its a new engine job. sell it while you can or put up with it, it will eventualy start burning oil!