Auris rattles on cold starts

[sepekaski]

Hi everyone! I really need your help asap. My Toyota Auris hybrid 2013 has a weird sound on cold starts (kind of knocking sound) and this started when the weather was getting colder. Now it happens every once in a while but stops when the engine is warm. Any idea what is going on? I attached the link which describes the sound very well. The sound does not last long. 

 

 

[TonyHSD]

Hi,

the knocking you have is typical for these cars/engines and is as a result of misfire. There are three main reasons for misfire in this engine or any combination of all 3:

1. Egr cooler, valve, pipe and intake manifold- egr cleaning procedure is required, no need to replace parts except manifold gasket 

2. Moisture locked in intake manifold- usually present in the early gen3 engines 2010-2011, 2012 has updated intake and should reduce that happening however it is possible especially if you start stop using the car on very short trips 

3. Fuel injectors dirty, and cause extra liquid fuel to enter the combustion chambers on some or all cylinders, fuel cannot ignited and burn properly, misfire is happening 

To determine which one from the above is most likely the issue you need to answer few questions: 

What is your mileage.? 
What petrol are you using E10 or E5? 
Where and how do you use your car? Town, motorways etc , how many miles per trip? 
Have you ever used any fuel additives to clean your injectors? 
 

Best to take action and don’t leave the car knocking for too long time without fixing it as this can lead to ore serious problems like clutch damper damage, engine damage too. 
Regards 

[sepekaski]

Okay thanks a lot for your answers. The option 1 sounds most convincing to me. So it requires the cleaning of the egr system?

 

I 

[TonyHSD]

29 minutes ago, sepekaski said:

Okay thanks a lot for your answers. The option 1 sounds most convincing to me. So it requires the cleaning of the egr system?

 

I 

For the beginning I can highly recommended to you to switch to E5 99 premium petrol, and see if anything changes, my car has all cleaning procedures done, it’s all fine and with poor quality or E10 fuel still does knock on cold start from time to time, since I use only 99 E5 for two months now never had any knocking on cold. You can also use wynns injectors cleaner , important to follow exactly the instructions on the label and see how is going, it helped me before. Give it a good motorway run after the additive. 👍

[sepekaski]

Ok great. Thanks. I will start by switching to E5! Lets see what happens.

[sepekaski]

Hi! My service just checked this problem. Could not find anything even though they checked egr velved etc.. they only found dirty pistone heads. What can it be?

[TonyHSD]

2 hours ago, sepekaski said:

Hi! My service just checked this problem. Could not find anything even though they checked egr velved etc.. they only found dirty pistone heads. What can it be?

Carbon buildup from age and mileage, oil burning and egr recirculating burning of exhaust gases. Higher octane fuel, some additives and few motorway runs should fix it. , if anything else been properly checked and serviced. 

[furtula]

You say the rattle lasts until the engine warms up, but you also say that it happens sometimes, and does not last for long.

With this temperatures engine needs some time to warm up.

So how long does the rattle starts? Is it only for like 1-2 seconds on cold start when car is sitting overnight, or it lasts maybe a minute or two?

[AisinW]

It is possible that ice formation in the intake manifold when the temp is low. There is a TSB about it and revised intake manifold for 2ZR engines has been released. Check from your service history if it had been done in yours or not. Yours is 2013, I am not sure if it has old intake manifold. It is slso possible that the VVTI sprocket does not have enough oil pressure at start up. It does sound like upper part noise or valve train. 

https://priuschat.com/threads/new-service-bulletin-for-engine-knocking-at-startup-t-sb-0012-10.102200/#post1449615