Aygo rough idle

[ifama_k]

Hello everyone, hope you're all well and keeping safe. 

I've purchased an aygo recently and it has a rough idle at the very start. Once you put your foot down and bit the engine idles smoothly. Things I've already done. 

Cleaned throttle body 

Cleaned MAP

Cleaned PCV valve 

Changed spark plugs (denso)

Any suggestions on what it could be? 

Any help appreciated. 

Regards Mal. 

Edited March 22, 2022 by ifama_k
Made mistake. Maf instead of map

[Dave the aygo]

Does it do it all the time or only when it's cold my last one use to shudder when pulling off from cold when it got warm it was ok

[flash22]

Mileage ?, i would suspect a plug or coil, the 1KR doesn't use a MAF it uses IAT and MAP sensor, see if it has any codes stored

the standard plugs are copper so are done at 50-60k  miles

[ifama_k]

4 minutes ago, Dave the aygo said:

Does it do it all the time or only when it's cold my last one use to shudder when pulling off from cold when it got warm it was ok

Hi Dave, it's all the time. It seems to be running a bit rough at idle but once you rev it. It's fine. 

[ifama_k]

1 minute ago, flash22 said:

Mileage ?, i would suspect a plug or coil, the 1KR doesn't use a MAF it uses IAT and MAP sensor, see if it has any codes stored

It's the sensor behind the throttle body. Plugs have been changed and leads seem okay. Yes that's the plan to get it booked in. Just looking for a toyota specialist near me. 

Just seeing if there's anything I can check before I take it in. 

[ifama_k]

Apologies 

The mileage is 66k and the car is a 2014 with ftsh up until 52k 2019 and then 2 private after this. 

[flash22]

Swap coils 1 and 2 around and see if that makes a difference, it maybe a lazy injector - some injector cleaner in the tank wouldn't hurt

[ifama_k]

1 minute ago, flash22 said:

Swap coils 1 and 2 around and see if that makes a difference, it maybe a lazy injector - some injector cleaner in the tank wouldn't hurt

Thanks, I've already run a bottle of fuel system cleaner through half a tank full. I'll try swapping the coils over and see what happens. 

[ifama_k]

37 minutes ago, ifama_k said:

Thanks, I've already run a bottle of fuel system cleaner through half a tank full. I'll try swapping the coils over and see what happens. 

No luck with swapping the coils over. Swapped 1 and 2 and then 2 and 3. 

[flash22]

Must be a vacuum leak as soon as it warms up it seals

[ifama_k]

2 minutes ago, flash22 said:

Must be a vacuum leak as soon as it warms up it seals

It's rough all the time. Doesn't matter if warm or cold. Worst at 1500rpm once you go over 2000rpm it's smooth. 

[flash22]

It needs a proper diag and a look at the live data to see what's going on

[Cyker]

The Aygo I drove was very rattly at low RPM, almost like a diesel, but got smoother the faster it revved.

Do you know anyone else with an Aygo you could compare it with to make sure this isn't just the normal 3-pot rattle?

Might be one cylinder has a bit lower compression than the others, or one of the engine mounts is a bit dodgy?

[steveo3002]

agree it needs plugging in

what would swapping coils do ?  transfer the miss fire to a different cylinder?  dont see how it would prove anything 

[Guest]

9 minutes ago, steveo3002 said:

what would swapping coils do ?  transfer the miss fire to a different cylinder?  dont see how it would prove anything 

If the problem was a faulty coil it would move the misfire to a different cylinder.

This is a very common fault finding technique, especially on VW cars (but it's applicable to all makes) because they had real problems a few years ago with faulty/unreliable batches of coils.

[Gray86]

BG44k is the best injector cleaner on the market - I’d recommend a can of that in the tank, and see where you go from there. Sorted many rough idling issues for me 

[flash22]

Thinking this through, it could be a EGR issue

[ifama_k]

Apologies for the late reply. Being a new member TOC wouldn't allow me to message until 24h had passed. 

[ifama_k]

22 hours ago, flash22 said:

It needs a proper diag and a look at the live data to see what's going on

Booked in with a toyota specialist for next Thursday. 

[ifama_k]

21 hours ago, Cyker said:

The Aygo I drove was very rattly at low RPM, almost like a diesel, but got smoother the faster it revved.

Do you know anyone else with an Aygo you could compare it with to make sure this isn't just the normal 3-pot rattle?

Might be one cylinder has a bit lower compression than the others, or one of the engine mounts is a bit dodgy?

No sorry I don't know anyone else with one. First time in my life I've driven such a small engine. I assumed it was supposed to be like that until my daughter who I bought the car for pointed it out.

[ifama_k]

6 hours ago, Gray86 said:

BG44k is the best injector cleaner on the market - I’d recommend a can of that in the tank, and see where you go from there. Sorted many rough idling issues for me 

Ordered some today. Thank you. I've used this before on my diesel engines. Really good product. 

[ifama_k]

2 hours ago, flash22 said:

Thinking this through, it could be a EGR issue

We're is the egr located on this engine? Can't seem to find it. 

[flash22]

iirc its right rear/side of the engine bolted to the head under the air box

 

[Gray86]

On 3/23/2022 at 4:19 PM, ifama_k said:

Ordered some today. Thank you. I've used this before on my diesel engines. Really good product. 

Guessing you used BG244 for diesel. Just as good a product 👍

[ifama_k]

Hi guys, apologies I haven't replied or been on here. I caught covid again and already suffering from lung damage from when I caught it last September it knocked me for 7. My health is not good at the moment and I'll have to look into the car when I'm doing a bit better. For now I'm too ill. 

Thank you for all your help and advice. 

Regards Mal.