Tappet noise or something else?

[Bikergonebald]

I recently bought a 2004 1.4 petrol 16v. It’s only done 29000mls but had stood for 7 years. I’ve been through servicing everything but it still has a noise that sounds like tappets. It improves when it gets hot so it’s not as audible at tickover.

The strange thing is that while it’s quiet(er) at tick over and when revved freely it is still noisy under load. The severity of the noise is worse as more throttle is used but disappears as soon as you take your foot off the throttle?

Is this normal for tappet noise?

I thought it might be the exhaust manifold gasket so I changed that but it didn’t fix it.

Thanks
Kevin

[littlepolo]

Noisy tappets are common across many VAG group vehicles. Very important to use the correct oil and filter and change regularly (according to conditions). If you are saying it quietens down overall when hot (normal) at both idle and when revved but then is noisy under load that doesn't sound like tappet noise (which would generally quieten down at revs because the noise cannot be heard over the engine noise). Given the low mileage I'd be surprised if it was the other problem - piston slap - but it could be. Piston slap is generally noisy when the engine is cold, quietens down when the engine is hot, and is noisy under load.

What is the service history and what oil is in it?

Is it using any oil?

[Bikergonebald]

Thanks for replying.

The answers to your questions won’t read well. It has a stamp for its first service and nothing else so I don’t know, the back street dealer I bought it from had changed the oil but I don’t know what’s in it. I intend to change it again very soon but I’ve put some oil additive in and wanted to run it for a bit to let that do something before changing the oil.

There’s no sign of blue smoke at all and the crankcase isn’t pressurising but I will research more about piston slap.
I know it’s the wrong noise for big ends or mains but what about little end noise? When is that noticeable?

If it is tappet noise what damage is it doing?

Thanks
Kevin

[littlepolo]

The most likely failure points are tappets and piston slap. The latter, although a nuisance, can be tolerated (caused by wear of the teflon coating on the pistons). Noisy tappets/wear due to insufficient oil maintenance/flow can also be tolerated (unless it's really bad - see my old engine replacement thread for photos). Unlikely to be big end or little ends.

Not sure what additive you've put in but I doubt it will work to offset wear. If the oil has congealed due the long standing period it might help. I gentle engine flush additive would be preferable to a strong cleaner due to risk to the seals. Suggest draining the oil and inspecting for fine metal particles. I use a magnetic drain plug which helps to see any deposits.

In my experience Fuchs and Quantum oils generally dampen engine noise better than Castrol Edge, Shell etc. However, Shell (Helix) is good for cleaning so you could run that for a few hundred miles, repeat, etc. and then switch to Fuchs or Quantum when the oil is looking normal.

[Bikergonebald]

Thanks for the tips. I’ll get on with the oil changes and hope it improves it. Otherwise I will live with it for now.

[bvs]

I used to have a Polo 1.4 16v and I found that using standard 95ron petrol made the engine 'pink' sometimes,we started using Tesco 99 momentum and that stopped the 'pinking',the pinking sound was totally unlike pinking on older engines and it sounded like a flat mechanical rattle which only occurred under load.They are fairly noisy engines whilst cold and as LP has already posted - use a good quality oil and filter.I always used the same brand of filter so that the 'Hex' on the filter was always the same size.I used fully synth 5w40 oil.

If you look inside the petrol filler flap it should say which grade of fuel is correct iirc ours said 98/95 which I took to mean that 98ron was the correct fuel.

[RUM4MO]

bvs correct me if I'm wrong but if 98 octane is mentioned I'd expect that the engine output would be 100PS and not the lower output version, typical engine codes were BBY for 75PS output and BBZ for 100PS output sometimes linked to an auto trans box.

Trying 98 octane is certainly worth doing over the range of a full tank of fuel, maybe go for an expensive brand if doing that, it Shell to see if it improves anything.

I've used Comma Petrol oil flush a few times, it can be left in the car for 100 miles.

[bvs]

Hi Rum...
Our engine code was AUB - 100 HP
TBH the Tesco 99 seemed to be ok - we only had one fill up where the car pinked afterwards,but I suspected that the wrong grade of fuel was in the filling station Tanks LOL