(2015) Aygo engine runs best when cold and not as well when hot?

[Cal5028]

Hello

I recently bought an Aygo from 2015. Runs and drives great, but I think it might need some engine / injector / fuel system cleaning. 

The essence is this - it runs very well when cold and I'd say 95% well when hot. The issue is that it idles fine and if you accelerate moderately to hard, it'll do so without any hesitation. A gentel acceleration will make it vibrate a bit in the engine, though, and when maintaining a speed and when the revs are below around 3000 (say city driving), it seems to.. vibrate a bit from the engine? Not a misfire as such, but it feels like it's not igniting all cylinders at 100% - more like maybe 95%? The engine vibration stops when accelerating and it stops when above 3000 rpm so it's PERFECTLY smooth at motorway speeds or when accelerating moderately.

I've driven it 700 km the past week or so and it has become a lot better making me believe it just needs cleaning. The previous owner was an elderly man who didn't drive it much, so I imagine it's just full of carbon.

Does anyone have better ideas? Does it sound like spark plugs might need changing? Else I'll just add some additive to the fuel and see if that clears it up.

Cheers!

[gampla]

Any codes?

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[Cal5028]

3 minutes ago, gampla said:

Any codes?

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Nope no codes and it's not ACTUALLY misfiring - all cylinders feel to light up at all times, it just feels like it's missing the last few percentages to become absolutely 100% smooth. Would it throw an engine code if it was "bad" or so? I'm thinking of changing the spark plugs and adding fuel cleaning additives at the moment.

[gampla]

Nope no codes and it's not ACTUALLY misfiring - all cylinders feel to light up at all times, it just feels like it's missing the last few percentages to become absolutely 100% smooth. Would it throw an engine code if it was "bad" or so? I'm thinking of changing the spark plugs and adding fuel cleaning additives at the moment.

Pull fuel pump fuse remove lead and spark see if you have strong spark on all

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[Cal5028]

2 minutes ago, gampla said:

Pull fuel pump fuse remove lead and spark see if you have strong spark on all

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Will definitely try! It seems to run fine for the first 5 minute or so at 100% and no hesitation on acceleration, and it just seems to hesitate a small amount when hot - sounds like it could be spark related, but I'm not sure if a clogged up fuel system / dirty injectors would do the same.

[gampla]

Could be anything from spark to fuel filter to air filter ecu needs fuel pressure and air flow to calculate the perfect mix at high speed to will need more fuel to match air intake

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[Catlover]

How many miles has car done? Are services up to date and done as required? Have plugs been changed, if so what mileage?

[Cal5028]

8 minutes ago, gampla said:

Could be anything from spark to fuel filter to air filter ecu needs fuel pressure and air flow to calculate the perfect mix at high speed to will need more fuel to match air intake

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I'll try with new spark plugs and some cleaning additives and see if it makes a difference. Thanks!

[Cal5028]

6 minutes ago, Catlover said:

How many miles has car done? Are services up to date and done as required? Have plugs been changed, if so what mileage?

It has done 26,000 miles, all services up to date (last service around 2 months ago). Plugs have never been changed and are therefore around 5 years old. 

[gampla]

It has done 26,000 miles, all services up to date (last service around 2 months ago). Plugs have never been changed and are therefore around 5 years old. 

I would also change fuel filter and use fuel like BP ultimate

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[Cal5028]

7 minutes ago, gampla said:

I would also change fuel filter and use fuel like BP ultimate

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I've filled it up with Shell V-Power and it already seems better from just driving it around! Making me believe it just needs a proper engine clean.

[Catlover]

Give it a good blast on the Mway or whatever you have where you live. Hold onto lower gears longer to keep revs higher. Try to blast any much out of engine and exhaust system.

[steveo3002]

might well clear up with a proper service and some longer runs , premium fuel will help too

[fordulike]

Original plugs are long-life and IIRC, don't need replacing until 50k+ miles. I had mine done at around 35k miles, as I didn't want them seizing in the block with age. They were in rude health, so no worries there.

Had a slight vibration around the 2000 rev mark, which was cured with some Wynns Catalytic Converter and Lambda Cleaner and a blast on motorway.

[Cal5028]

Update on the situation! 
I decided to give it some love, so I changed out the old spark plugs with some new Toyota Iridium plugs. It cleared up nearly everything! Car runs much stronger and without the hesitation earlier.

I’m still getting a little engine shake / throttle hesitation at just around 2000 rpm, just like fordulike talked about above. I’ll make sure to try some lambda-cleaner!

[Cal5028]

Edit: If anyone has any good ideas on how to give the rest of the engine a good tune-up, any suggestions would be great! I've changed the spark plugs and with its recent service, it got new oil, filter and air filter. I'm thinking of removing the O2 sensor / lambda to give it a good clean. I imagine the car has been mostly town driven, meaning it just needs a good clean out. 

[fordulike]

As it's had a recent service, then I would do a few runs where you use the whole of the rev range. 2nd gear up to 6000 rpm is fine and these engines love to rev. Only do this when the engine has warmed up though, and good idea to stick some of that Wynns stuff in first.

[furtula]

I had similar issue with my car, it was sluggish, underpowered. As soon as you start it, it felt like it had much more power, but once warmed up, it changed, and became sluggish.

I attributed this to mostly city driving, stop start, very slow, and low in rpm's.

Moved to a more rural area, where in my commute i even drive up to 70-ish, and the car changed back.

You can also try reseting the ECU, taking the Battery off for 10 minutes, then reconnect, let it idle for 10 minutes, then take the car for a drive.