Engine sludge? and acceleration question

[Cal5028]

Hello

I bought a mk2 aygo recently and the previous owner must have been a real slowpoke. The car has low mileage (around 6000 miles a year) and probably most were in city. Can engine sludge alter performance? sometimes when I accelerate, the car feels fine and will perform fine for like an hour and then you can physically feel it'll just remove like 10hp at random, and it won't stop doing it again for weeks. It feels fantastic when it runs perfect, but it only does for like 2 hours out of 10. engine also shakes a little when it happens.

could it be like the VVT getting a blood clot of oil every now and then, making the car just run a little worse? There was a little sludge on the oil filler cap when I bought it but that's gone after driving it moderately hard for a few months. car definitely ran a lot worse when I bought it and it steadily became better the first few months, but the last haggle with the random tiny misfires is driving me mad and it's not really been improving the last couple months.

any help is appreciated, thanks guys

oh and is it possible to add carplay to the cars? I do have the infotainment screen with backup camera

[FROSTYBALLS]

When was it last serviced, and what is the service history like?

As regards Carplay your head unit won't be compatible. The only way is to replace the head unit with one from the post facelift Aygo from mid 2018, but be aware you need the head unit with three buttons on rather than the two.

There are a couple of previous topics on this.

[Chris Boddum]

2 minutes ago, FROSTYBALLS said:

When was it last serviced, and what is the service history like?

As regards Carplay your head unit won't be compatible. The only way is to replace the head unit with one from the post facelift Aygo from mid 2018, but be aware you need the head unit with three buttons on rather than the two.

There are a couple of previous topics on this.

hello! service history is alright, with it going a little over service once back in 2016. the car was serviced back in september or so, and I was told by my mechanic to give it some good hot runs on the motorway to clear up some gunk. I did and it drives better, it's just.. not perfect. can engine sludge affect my performance? could it be fuel related?

I'll check out the threads, thanks!

[TonyHSD]

It can actually, you can check by removing the oil filer cap and look inside the engine any signs of dark red - brownish like on the metal parts, also oil dipstick if it has same formation. Check if air filter is new, “serviced” sometimes means just a new oil or perhaps not even that. Best to check yourself everything again. You can also use some petrol injector cleaner, helps a lot with cleaning and general performance. 
Once all that checked you can take it for a run , no need to drive fast or trashed out, just longer drive 1-2 hrs. 👍

[Chris Boddum]

Hi! I had a similar issue with mine. I had the chain tightened up, which did solve a lot of my issues. Seems to happen if the car wasn't serviced regularly enough.

[Cal5028]

21 minutes ago, TonyHSD said:

It can actually, you can check by removing the oil filer cap and look inside the engine any signs of dark red - brownish like on the metal parts, also oil dipstick if it has same formation. Check if air filter is new, “serviced” sometimes means just a new oil or perhaps not even that. Best to check yourself everything again. You can also use some petrol injector cleaner, helps a lot with cleaning and general performance. 
Once all that checked you can take it for a run , no need to drive fast or trashed out, just longer drive 1-2 hrs. 👍

Hello! yeah, oil definitely went black very quickly after service (within like 200 km / 120 miles) and I do mean BLACK, not dark brown or sirup, indicating that there has to be some pretty good deposits in that engine. dipstick also looks very dark. even though I've only done 8000 km / 5000 miles since the last service, I should probably just do an oil change now. I've tried with injector cleaner and Shell V-Power and it helped, especially just after I bought it (the car could barely keep 70 km/h / 45 mph because the engine kept stumbling over itself. it can do that fine now, it just vibrates a bit. incredible that I've never had a check engine light!). I imagine the oil just can't do more cleaning since it's done its job, meaning I should probably get some new oil and let it do more cleaning... I guess? 

 

[steveo3002]

take the sump off and clean it if youre capable 

[Cal5028]

1 hour ago, steveo3002 said:

take the sump off and clean it if youre capable 

yeah, I've had it in mind. I'll change the oil and see if it helps anything. 

I just took a drive in the car and yup, it's back to its old self. It feels like the performance is down 20% and it just doesn't rev as freely with few vibrations. It had worked perfectly fine for 2-3 days and while cruising at 30 mph for a while, I noticed that it quite suddenly began struggling ever so slightly and that I had to press just a bit further on the accelerator to keep it going. It really does feel like something is clogging up somewhere.

I checked the oil filler cap and there is a small amount of yellow sludge on it, but not a lot. The oil looks really dark though, and there is some black sludge in the hole down into the valve cover.

[Bernard Foy]

 

1 hour ago, Cal5028 said:

yeah, I've had it in mind. I'll change the oil and see if it helps anything. 

I just took a drive in the car and yup, it's back to its old self. It feels like the performance is down 20% and it just doesn't rev as freely with few vibrations. It had worked perfectly fine for 2-3 days and while cruising at 30 mph for a while, I noticed that it quite suddenly began struggling ever so slightly and that I had to press just a bit further on the accelerator to keep it going. It really does feel like something is clogging up somewhere.

I checked the oil filler cap and there is a small amount of yellow sludge on it, but not a lot. The oil looks really dark though, and there is some black sludge in the hole down into the valve cover.

Yes change the oil and filter, make sure when you are draining the oil that the engine is hot so that the old oil will drain freely. Also put a new set of plugs in the car. Take it for a good long run and if no improvement then consider taking it to a Toyota dealer for fault analysis on their computer.

[Cal5028]

22 minutes ago, Bernard Foy said:

 

Yes change the oil and filter, make sure when you are draining the oil that the engine is hot so that the old oil will drain freely. Also put a new set of plugs in the car. Take it for a good long run and if no improvement then consider taking it to a Toyota dealer for fault analysis on their computer.

Yeah, it'll be the oil and filter first, but I'll definitely think of scraping the sump later. I've already added new Iridium plugs to it, so that should be alright. We decided to remove the valve cover this afternoon, and there is definitely is quite an amount of sludge. My mechanic says it's not unusual for the Aygo and that he has seen "much worse", but that we agree that we need to do something. However, I spoke with the previous owner and he confirmed that the car has done many short trips at low speeds.

I think I may just need to overhaul many of the service items on it, but what are we thinking here? Obviously oil and filter (including air filter) - what about EGR valve and especially the breather hose? I've also head of cleaners that you can spray into the intake manifold - is that recommended for the Aygo as well? I did notice that the car suddenly ran GREAT in the coldest of days (-6c / 21f). It ran fine as well today at 6c (42f), but after an hour or so of driving, it VERY suddenly snapped back being its old self. It honestly ran really good first off at 6c for that very hour, which was much better than usual, so I'm not 100% sure if temperature is to be considered - still quite a coincidence if not!

[Bernard Foy]

1 hour ago, Cal5028 said:

Yeah, it'll be the oil and filter first, but I'll definitely think of scraping the sump later. I've already added new iridium plugs to it, so that should be alright. We decided to remove the valve cover this afternoon, and there is definitely is quite an amount of sludge. My mechanic says it's not unusual for the Aygo and that he has seen "much worse", but that we agree that we need to do something. However, I spoke with the previous owner and he confirmed that the car has done many short trips at low speeds.

I think I may just need to overhaul many of the service items on it, but what are we thinking here? Obviously oil and filter (including air filter) - what about EGR valve and especially the breather hose? I've also head of cleaners that you can spray into the intake manifold - is that recommended for the Aygo as well? I did notice that the car suddenly ran GREAT in the coldest of days (-6c / 21f). It ran fine as well today at 6c (42f), but after an hour or so of driving, it VERY suddenly snapped back being its old self. It honestly ran really good first off at 6c for that very hour, which was much better than usual, so I'm not 100% sure if temperature is to be considered - still quite a coincidence if not!

Another thing I would try as your problem seems to be temperature related is flushing out the cooling system. At this moment I wouldn’t recommend an engine flush, because it can be something that some mechanics are hesitant to do, as you need to strictly adhere to the instructions, otherwise it can be counterproductive.

[steveo3002]

get a few oil filters and just fill with the cheapest oil you can find , run it for a couple of days and drain it , keep doing it until it stays clean looking , diesel spec oil has more cleaning additives 

yes you can get stuff like seafoam that you spray into the inlet , this wont clean the oil system  , only the inlet tract /valves etc 

another thing you can do is drain the oil , then over night put about 2ltrs of parafin into the engine , this will soak the sump and hopefully clean it up a bit...drain and refull with oil then repeated oil changes to get rid of it 

[TonyHSD]

Use stp engine flush, it is a very good stuff and helps a lot cleaning engine internally and yes two three oil changes between 2-3k miles will help a lot. I am not sure cleaning the engine will help with performance but it’s is good for the engine itself long term. If doesn’t perform well you may need to think about something with fuel air mixture and timing, use regular petrol and add injector cleaner ( catalytic converter cleaner) works better than using a high octane fuel. 
Just experimenting one thing at a time and monitor to find out what exactly helps the most. 👍

[Cal5028]

Thank you all for the answers, I’ll take them all into consideration! It should be noted that there are no check engine lights, making this a little hard to get to the bottom of.

I did notice that the car has become a little harder to start when cold. It’s not hard, but it sometimes takes a few extra turns on the starter motor before it fires. I’m thinking EGR or O2 sensor? It’s just that there are no codes! So confusing. 

[steveo3002]

doubt egr or o2 would effect cranking /start up

have you replaced the spark plugs /air filter ...or at least inspected them?

[Cal5028]

1 hour ago, steveo3002 said:

doubt egr or o2 would effect cranking /start up

have you replaced the spark plugs /air filter ...or at least inspected them?

yup, air filter replaced in September and spark plugs in October with new Toyota iridum plugs. We did two things today, one being doing the chain maintenance bulletin (essentially removing any slack from the chain, just to rule that out as an issue) and checked for codes. I didn't hear the number he listed, but he said it had a generic code for "startability malfunction". My mechanic told me it's a generic code and that it could be many things. Ugh! I'm not worried about it not starting as it is no issue, it always starts, it's just that it sometimes takes like half a turn more on the starter and sometimes it doesn't.

It should be noted that there seems to be some difference with a tighter chain, but it's still not quite there. Could it seriously be that the difference between -6c and +6c kept the chain.. cooler? making it feel like the car ran fine? I just don't even know anymore.

Next step is replacing the oil and filter.

 

[steveo3002]

mine cranks a little longer in the freezing weather so maybe no issue there

[Billyboy81]

Could it be you have a faulty coil pack or HT lead that's breaking down when hot causing the rough running?

[Cal5028]

8 hours ago, steveo3002 said:

mine cranks a little longer in the freezing weather so maybe no issue there

Ah, sounds alright then, and it does fire perfectly fine every time

2 hours ago, Billyboy81 said:

Could it be you have a faulty coil pack or HT lead that's breaking down when hot causing the rough running?

that's actually a very interesting theory! The car has done under 40k miles though, would it sound plausible at such low mileage? I'll put an ohm-meter on them.

On a general update - we gave it an oil and filter change with 0w20 instead of the previous 5w30. Not that much of a difference, but the previous oil was BLACK. we put the old oil through some basic tests and there are no metal fragments or anything worrying in it. As the car has progressively driven better and better each day when the old oil was new, I hope that just driving it now will clear out anything in the engine with the new fresh oil.