1.4 tdi engine knocking/tapping

A

agjb90

Member
Evening all,

Having a few issues with my 1.4 tdi and was wondering if anyone has came across similar issues,

Engine noisier than usual tractor noise lol,
Tapping/knocking especially when just started or under heavier acceleration

Vehicle is not down in power, no warning lights on, no noticeable smoking issues

Oil change with slightly heavier oil made no difference at all

In love with the car but the noise is annoying and any help would be much appreciated

Thanks 👍
 
Could be the dual mass flywheel if its a 90 or possible oil pump timing chain or just something vibrating like a heat shield
 
It's a 75bhp they don't have dmf do they?

I will try get a video tomorrow, I'm thinking it's diesel knock tbh will maybe try testing the injector loom plug for resistance aswell tomorrow
 
When my 1.4 petrol had too much piston tapping noise, I went (EDIT: 5w40 means its thicker than 5w30!) from 5w30 to 5w40, and not the other way around. Others recommended it to reduce stress on the pistons, and it'd worked great, tapping noise has been reduced significantly since, also I barely do long drives, so I'll stick with the thinner oil.
 
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i solved this problem with adding 0,5L of 2stroke semi-synthetic oil for every full tank of petrol. I am using this during winter season, as no need in hot summer days. It work perfectly.
But always wanted to know what this sound is. It seems like the piston valves is where the sound is coming form.
Next time will try to go to thinner engine oil. It makes perfect sense.
 
Howey said:
If you have put 40w in that's thicker than 30w?
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I had to look it up, yes you're right, that means its thicker.
That's odd, I've followed a recommendation, going from 5w30 to 5w40, and it did help with about the noise, but I actually thought oil has to be thinner then, but its actually thicker.
That makes me question, who thinner oil would work.
 
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Sylvester said:
30w to 40w
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It would help if you spell out precisely what oil you use now, and what oil you previously used. I very much doubt you have ever used either 30w or 40w oils, which would be ridiculously thick winter grades.
 
steve_c said:
5w30 and 5w40 have the exact same viscosity at start up.

Identifying the best oil grade for your engine is nowhere near as simple as you seem to think it.
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To be honest I've only followed this recommendation from another A2 owner, he had the same loud tapping issue, and 5w40 definitely worked for me as well. Even the neighbour had mentioned it, the car is not as noisy as used to be. It's definitely noticeable when I start the engine at 5am, after few seconds the tap-tap noise almost completely goes away. I'll keep using the 5w40 grade for sure. Cheers
 
Sylvester said:
To be honest I've only followed this recommendation from another A2 owner, he had the same loud tapping issue, and 5w40 definitely worked for me as well. Even the neighbour had mentioned it, the car is not as noisy as used to be. It's definitely noticeable when I start the engine at 5am, after few seconds the tap-tap noise almost completely goes away. I'll keep using the 5w40 grade for sure. Cheers
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Engine oil takes longer to come up to temperature than coolant - typically around 15 minutes to reach full operating temperature.

If you want thicker oil from start up you need to switch to a 10w30 or 10w40 oil.

Thicker oil doesn't run as easily, but can fill the gap between worn pistons / rings and cylinder bores. If you need thicker oil, it's best to establish the precise nature of the problem beforehand by having a professional carry out a compression test.
 
steve_c said:
Engine oil takes longer to come up to temperature than coolant - typically around 15 minutes to reach full operating temperature.

If you want thicker oil from start up you need to switch to a 10w30 or 10w40 oil.

Thicker oil doesn't run as easily, but can fill the gap between worn pistons / rings and cylinder bores. If you need thicker oil, it's best to establish the precise nature of the problem beforehand by having a professional carry out a compression test.
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There's a risk that using thicker oil can overload the, (15+, year old), pump. Also thicker oil flows slower.
Mac.
 
steve_c said:
Engine oil takes longer to come up to temperature than coolant - typically around 15 minutes to reach full operating temperature.

If you want thicker oil from start up you need to switch to a 10w30 or 10w40 oil.

Thicker oil doesn't run as easily, but can fill the gap between worn pistons / rings and cylinder bores. If you need thicker oil, it's best to establish the precise nature of the problem beforehand by having a professional carry out a compression test.
Click to expand...
Compression test is on the list as well for sure, cheers.
 
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