Surging symptoms ?

[Stecha]

Mine is a late 2008 Mk1 petrol manual Aygo
Its done around 65000 miles
Engine seems fine, serviced myself
So, it seems to have an odd surging like thing sometimes happens
Normally or usually it can be flat as a pancake, especially on gradients
Its not brakes btw
Sometimes, it seems to want to surge / take off, even on a gradient
All a sudden its "whoa" & "yes" lol, its most un Aygo like
So, what's likely to be wrong or maybe right ?
I think atm unlikely to be fuel pump
Maybe relevant may not be, but, I run a OBD cheapo digital gauge thing, that says normally temperature is 84C
So far there doesn't seem to be any rhyme or reason to it
And btw its does it AC on or off, so not that either
Thoughts ?

[TonyHSD]

Hi Steve, 

when you scanned the car have you found any trouble codes or all was clear? 
Often on petrol cars when having idle issues or acceleration without any faults stored happens to be because of a dirty throttle body. If you car has never had it clean it’s a good idea to start from there. You can buy any carb and throttle body spray and clean soft towel( cloth) , undo the body and clean thoroughly. If yup haven’t done this job yet best to watch some videos on YouTube first to get familiar with the job. Also you can clean MAF/MAP sensor which maybe located close to the body onto intake manifold. This sensor cleaning is only few short shots and let it dry. After mounting the body, turn off all electrical accessories, lights, heating, ac, music, everything. , start the engine and let it running for 15 min , do not turn steering wheel during this time too. Best practice also is to disconnect 12v Battery negative terminal before start any work and then connect. The ecu will need to reset itself and then re learn after cleaning procedure. That’s pretty much all. I am not sure this will help your situation but as preventative maintenance is recommended on older cars. , 50000+ miles 👍

[Stecha]

Hi Tony

Thanks for your suggestions

There were no codes when I checked it a few weeks ago

I did do all the things you mentioned when I first got it a year or so ago and only done less than 5000 since then

But, I will try them all again soon to make sure

Thanks

[TonyHSD]

1 hour ago, Stecha said:

Hi Tony

Thanks for your suggestions

There were no codes when I checked it a few weeks ago

I did do all the things you mentioned when I first got it a year or so ago and only done less than 5000 since then

But, I will try them all again soon to make sure

Thanks

Hi, 

if you have done all that most likely it’s something else then. Perhaps try different fuel like E5 99 and see if any difference. Some injector cleaner in the fuel. I had once some pulsating on hard acceleration and I fixed it with using wynns catalytic converter and lambda sensor cleaner. 

[Stecha]

Thanks, That Wynns stuff sounds like a good idea

[fordulike]

14 hours ago, TonyHSD said:

Perhaps try different fuel like E5 99 and see if any difference. Some injector cleaner in the fuel. I had once some pulsating on hard acceleration and I fixed it with using wynns catalytic converter and lambda sensor cleaner. 

I use the Wynn's stuff twice a year and it appears to be good stuff. Preventative maintenance is high on my list when it comes to running a car.

Also, I never jumped on the E10 train with my Aygo. I'd rather not chance that the E10 causes problems further down the line, when it's too late. BP or Shell premium E5 fuel for me every time. The Aygo is pretty economical anyway, so doesn't really save much cash by switching to the E10.

[Hybrid21]

14 hours ago, TonyHSD said:

Hi, 

if you have done all that most likely it’s something else then. Perhaps try different fuel like E5 99 and see if any difference. Some injector cleaner in the fuel. I had once some pulsating on hard acceleration and I fixed it with using wynns catalytic converter and lambda sensor cleaner. 

I used to run all my previous vehicles on Shell Vpower with no problems, swear by it. 👍

But use Esso E5 on the RAV4, certainly would never use supermarket fuel 😃

[Stecha]

I have been using E10 with Millers Ecomax

Regardless, my car isn't as flat as it was originally, there has been a small gradual improvement, since I got the car

[Hybrid21]

I would tend to use better fuel than spend money on additives.

[Stecha]

Yes

This is my first petrol car for at least 20 years and always used Millers with them, as it works well, at least on Diesels

[TonyHSD]

Wynns products are very good and helpful. I have been experimenting a lot with many products especially engine oils, additives, filters, wipers, tyres, brakes etc and also been in the trade with cars and parts and I found some additives actually work. The best indeed is to use quality fuels, however this is not possible always and here is when fuel additives can actually help. I tend to keep redex for petrol in the boot and when I noticed the engine doesn’t sound and perform well after refuelling I just add 125ml to the tank and can notice immediate effect. Wynns catalytic converter and lambda sensor cleaner helped me twice when I had pulsating issues, very important when using any additives is to follow instructions exactly. , in that add was 30ltr of fuel max. Driving continuously on motorway for 30 min or more also is needed, this rises the exhaust temperature and burns any soot accumulation. 👍 

[Guest]

11 hours ago, TonyHSD said:

I tend to keep redex for petrol in the boot and when I noticed the engine doesn’t sound and perform well after refuelling I just add 125ml to the tank and can notice immediate effect.

Same here, when the engine response 'feels' more sluggish and/or low/mid range torque is less I add 1 measure of Redex the next time I fill the tank.

[Chris Boddum]

Just here to vouch for Wynns cat and O2 sensor cleaner. It helped a lot with some surging / vibration issues I had a while ago.

[Stecha]

Thanks all. I will get some Wynns, soon as I can

[Stivino]

I had the same symptoms on a Chevrolet Lacetti, it was the EGR valve.

The EML light didn't come on and there were no fault codes.

[Stecha]

14 minutes ago, Stivino said:

I had the same symptoms on a Chevrolet Lacetti, it was the EGR valve.

The EML light didn't come on and there were no fault codes.

Egr, the most stupidest idea ever IMHO,

Thankfully, there isn't one yay 😀

[Stivino]

You're lucky as I think some of them have something like this.

[Stecha]

I have to say, one of the reasons I bought my Aygo was because there's no EGR,

[Guest]

The latest Aygos with the dual VVTi version of the 1KR-FE have a heated EGR valve.

[Cyker]

Heated?  Why's it heated? I would have thought it'd get plenty hot on its own given how hot exhaust gasses are!!  

 

 

[TonyHSD]

31 minutes ago, Cyker said:

Heated?  Why's it heated? I would have thought it'd get plenty hot on its own given how hot exhaust gasses are!!  

 

 

He probably meant cooled egr., similar to other Toyota models. 

[Cyker]

Ahh that would make sense!

 

[Stecha]

Another reason was, No Dual Mass Flywheel - a con IMHO

Do the new Aygos have a DMF ?

[Guest]

12 hours ago, TonyHSD said:

He probably meant cooled egr., similar to other Toyota models. 

The marketing bumpf says heated, don't ask me why I'm no engine designer!