Engine start noise

[VAskodas]

Hello, does anyone has this issue of engine making noise at start just for a couple of seconds? My Octavia 3 1.4 TSI making this noise especially when engine is “cold”. If I stop briefly and then start the engine there is no noise. If I leave it for about 1 hour for example, the noise is back same as before. Is it good or bad thing I don’t know. Some say it’s normal others say it’s common issue on VAG vehicles but not specifying what it is. 
Thanks in advance. 

[Blue8793841]

They say it's normal but it is not. There is too much movement on the wastegate actuator causing the noise. Something to do with pre heating the catalyst for emissions. That doesn't mean the turbo wastegate and actuator should make noise 🤬

[VAskodas]

Thanks for the reply.  That’s something. It make sense to me since the noise is generated during “cold start” and not when the engine is hot enough. 

Generally I my self do the repairs on my cars but Unfortunately I don’t know anything about waste gates and turbos so if you have more info on how to check this it would be great. 
Thanks. 

[Blue8793841]

If you want to check very important to make sure engine is cold and has not been started for hours! I burned myself badly just from driving car into garage for 30 seconds. Just grab the rod at the back of the engine and you will be able to shake it back and forth, in and out. Sometimes the only repair is a new turbo if the wastegate side is worn. If it's the actuator you can try putting a new one and resetting the adaptation. As there is no fix the problem will soon happen again. The larger 2.0 TSI have a clip you can add to the actuator rod to help stop the noise but I am not sure if you can fit it to the smaller engines.

[VAskodas]

Thanks. Very helpful information. Now I know at least in which direction I should get my self to find possible fixes or repairs. 
I will update this topic as soon I have something to add for discussion. 

[Blue8793841]

Yeah well it could be anything tbh, not saying it will be that but it's an easy place to start.

[VAskodas]

I found the waste gate rod and yes it has a significant play on both sides. I will upload a photo of what am I seeing and a video sample. (See here)
 

My guess is this is just a normal wear of moving parts. This is expected from this type of designs. 
 

Now, the fun part is how to resolve this with least effort possible 😁. Any thoughts?

[Blue8793841]

 

You can try putting a thicker 'E' clip to stop some noise but this won't account for wear in the actuator or waste gate, should still quieten it down a bit though.

[VAskodas]

1 minute ago, Blue8793841 said:

 

You can try putting a thicker 'E' clip to stop some noise but this won't account for wear in the actuator or waste gate, should still quieten it down a bit though.

This is exactly what I’m thinking but then again it will affect the vertical rotation of the joint putting more mechanical stress on the movement and my thought stops there. Maybe I’ll try putting some thin flexible metallic piece inside the joint to increase the overall thickness….im not sure about this but I’ll update as soon I try it. 

[Blue8793841]

It should be fine, VW actually do a special grease to lubricate the pivot as they are common to seize up. I used a ceramic high temperature grease on mine to stop it happening.

[VAskodas]

Maybe I’ll try putting a galvanized or stainless steel Grover to not only holding the forces between rod and plate in a way of spring but release the mechanical tension of the joint and it can also spin if necessary and still holding moving parts so they don’t rattle. 
 

I may be very well wrong about this but it just came to me now. 

[Blue8793841]

I think you might have a hard time as the shim would have to be very thin

[VAskodas]

Hi guys. I might found the reason behind the brief engine start noise on youtube comment.  
and i quote: "It appears that this is the oil pump gathering up oil after a period of engine rest, and that its ok and known about. This fits as it does not make this sound when you restart after only a short engine 'rest' when the oil has not had time to drain from the oil pump."

Link to the video here. 
 

This was my issue. The engine whining noise at start. The discussion went to another problem i also have which is the waste gate rattling noise and it is addressed here well. Thanks for that. 

[Blue8793841]

So the whine you think is the oil pump? Or lack of oil pressure to some engine part causing the whine?

[VAskodas]

1 hour ago, Blue8793841 said:

Or lack of oil pressure to some engine part causing the whine

Well i think this is what the comment states. When the engine is not running for a while and the oil drains down to the oil sump the next start up requires oil pressure build up so the oil can reach all engine parts. 
And apparently this process generates this noise during start up according to comment on youtube. 
 

On the other hand if this is a normal thing then it is a bad design. Thats my opinion. At least we know (not 100% ofc) what is causing the noise. 

[Blue8793841]

To be honest I work at a dealer and pretty much every TSI we have in has a rattle at idle for between 5-30 seconds maybe. I've just though it was normal. Cars from 10k to 100k.

But if it has suddenly appeared then maybe it would be worth investigating.

[Ootohere]

Well it is not normal. Because those that do not do it are not abnormal. @Blue8793841are you a technician, fitter or an apprentice at a dealership? 

[Blue8793841]

We don't know what exactly the noise is. We have nothing to go by. If the op could upload a video then there might be a chance we can help diagnose the problem.

[Ootohere]

If customers asking at dealerships about noises or other issues were not regularly told 'They all do that'  or 'Never heard of that before' more people might put trust in them.

@Blue8793841 Are you a Master Tech or Technician at a VW Group Dealership?

[Blue8793841]

No I'm not a technician at any VAG dealership. We don't know if he's referring to the catalyst pre heat or not.

[VAskodas]

To clarify things about the topic, my issue is a brief engine whine noise at cold engine start. I dont know if it is related to catalyst pre heat or oil pump for 100%. 

 

The mention about waste gate rattle was just a misunderstanding of the statement "engine start noise" of the title. That's on me.  But the info was useful anyway cuz i'm having this issue also. 

 

Anyway, i will upload a video of the issue so anyone can clearly understand what the issue is. 

Thanks.