TIGUAN 1.4 TFSI KNOCKING NOISE

[Caitlin]

Hey everyone, 👋

We have a 2014 Tiguan with the 1.4 engine and 6 speed box. It's only done 40k miles witn a full service history but had started making a rythmic knocking sound when on power at the low speed. It sounds like that knock older diesels make at low rev pull away but of cause this is petrol!! Or like it's running on three  but again it's not.


It's engine speed not road speed dependant, there are no codes and it's still got all its power. It's only on throttle and only really noticeable when under load. If you rev it at idle it's not really there.

We've changed the oil, filter, plugs and gearbox oil. I've had two mechanics look at it, the first thinks it's crank failing and the other disagrees but didn't know what it was. Both ruled out the cam chain which this engine is known for. I thought the gear oil made it quieter but over a longer rev range but hubby's not so sure.

There was no fleck in the engine oil but there was in the gearbox oil. With the car on stands, neutral and running, If you stab the throttle so it shoots up to 2k revs then the noise comes just one or twice but it sounds like it's in the gearbox - surely it's not doing anything though in that scenario? Clutch? Why would it be there when engaged though? Ahhh!

Kinda at a loss as to what to do now!

[johnnyroper]

I have had similar sounding noise on an a3 with that engine, turned out it was water pump. Simple test of briefly running with belt off and noise went away.
That was inly really noticeable when under load.

[SirDavidAlhambra]

Just a thought, but could it be due to low quality fuel? Might be worth putting in some premium unleaded from a non-supermarket source and see if that helps?

[SirDavidAlhambra]

Also could it be a driveshaft/CV issue, something like that slipping? I suspect not this however.

[Caitlin]

Thanks for the replies xxx

So we took the belt off and sadly the noise is still there.

We then put some of this in
 

And its a lot quieter. Finally we disconnected the hall sensor and cam adjustment sensors on the top and it's all but gone. I'm wondering what that means though! I assume its not ideal to drive it like that long term?

[johnnyroper]

If it's gone with those sensors disconnected then I would be suspecting timing chain or cam adjusters to be at fault.

[Mirez]

That sounds suspiciously like what I'm dealing with on a low mileage (35K) 2013 Audi A1 CAXA engine 1.4.
Mines rod knock caused by shite components, the shells on the conrod have elongated allowing excess play in the big end bearing. Fortunately, it looks like a new set of shells will save it but it's disappointing for a VAG engine with full service history.

It's short (mainly because I wasn't planning on sharing it) but you can see how sloppy the conrods are at the crank. There should be some side to side play of course but this is just loose! Cylinder 1 is just about ok, 2 and 3 are loose and 4 has some up/down play which I suspect is the cause of the noise.

Doesn't look to have damaged the crank:



Minimal wear:



I can't explain why disconnecting the VVT sensors reduces the noise but it did the same on this engine and I nearly went chasing a cam issue instead.   

[SirDavidAlhambra]

As a wise man once said, "Never skimp on buying quality components, for it is the labour that is the real cost of a repair."

And as a friend of mine used to say, "It does my head in replacing junk that doesn't work!" (What he meant was, never buy rubbish as it gives you more of a headache in the longer-term. He was a man of great foresight.)

[johnnyroper]

35k and bottom end is worn, that's shite and not what I would expect at all.
Saying that after messing about with a cayc engine today I can quite safely say a lot of vag stuff these days is not the best.

[Mirez]

I know, only reason I bought it was that it was low mileage with fsh so thought it would be sound. Supercharger pulley failed on dad's Tiguan last month and that's only on 17k. VAG has definitely had the bean counters in!

What's up with the CAYC? Those are normally either EGR or Injectors. Time consuming or expensive basically 😉

[johnnyroper]

Certainly appears like the bean counters have much more of a say, suppose they are have to recoup after the emissions gate costs

Injectors knackered, smoked like a trooper and ran like a dog. Such a clattery engine aswell absolutely zero refinement.

[Mirez]

Surprising as my Golf that had that engine was quite refined. Did he decide to do the injectors in the end?

[johnnyroper]

Well sort of after picking himself up off the floor and having a few beers once finding out the cost of them, the decision was made to fit 3 eBay cheapo's along with the one that was just a pass. Van will be moved on then and replaced with something else.

[Mirez]

Fair enough, they are crazy money so I'm not surprised! Let me know if you still want to code them.

The shells have arrived so I guess that's this weekends job. I'm in Scotland at the moment in a Peugeot 3008 which is actually really nice, I may trade the A1 in for one if it continues to be a pain!

[johnnyroper]

Managed to do it with a foxwell eventually, it asked for a security code and then needed an extra 0 adding at the end to make the 6 digits 7 and also some messing about with ignition and pressing cancel on scanner before they would save. Bit of a faff but git it done in the end. Less clattery now though.
Sure the Audi will be fine once you have done the shells this weekend,assuming you don't get snowed in up there.