Lumpy running 1.33L when maintaining a constant lower speed.

[Mooly]

A possible problem with my oil burning 1.33L. Mileage is 94k

I've detailed the symptoms below but my initial thoughts are it may be a sluggish or contaminated/faulty O2 sensor, the one upstream of the cat. Would anyone have any thoughts on that? There are no warning lights on.

The last few days have had me noticing what is definitely 'lumpy' running when maintaining a constant speed of around 30mph in 4th gear. Hard to describe, its a bit like imagining someone has a stretchy rope attached at the back and is giving it a pull every few seconds. If I accelerate really really slowly from such a speed (as slow as possible acceleration) then the effect goes. Motorway is fine. It also seems good during the initial warmup phase for a couple of miles from cold and then it begins.

I've topped up with E5 petrol (about a 50:50 mix E10 and E5 just now) just to see it it made a difference and have also added Wynns cat and Lambda cleaner. So far no difference at all.

Also tried ECU reset and was surprised this time just around how long it took to stabilise the idling speed. Even after a couple of miles and it was on the point of stopping, idling at just 400rpm or so. Another couple of miles and it became more normal. Idle quality is now good (steady with no hunting) but perhaps a little low still (no more than 800rpm). Acceleration and fuel economy seem normal and other then this 'lumpy' running at slower speeds it all seems super smooth and silky. I suspect after a motorway run the effect isn't as pronounced for a mile or two, possibly because everything will be hotter than town driving.

I also removed and cleaned the MAF sensor but it was absolutely spotless and nothing at all came off it.

[furtula]

Checked the state of throttle body, maybe dirty/sticky?

[Derek.w]

Have you replaced the spark plugs ?  just in case one is going bad.

Are any of the old ones oiled up?.

Is the gap on the plugs to wide? then replace them.

[Mooly]

9 hours ago, furtula said:

Checked the state of throttle body, maybe dirty/sticky?

I haven't looked at that that might be outside my comfort zone tbh. The inlet side where the MAF sensor is was super clean. Not even any deposits even if you wiped a finger in there. Totally clean.

 

8 hours ago, Derek.w said:

Have you replaced the spark plugs ?  just in case one is going bad.

The plugs are genuine and about half way through their life. When they were replaced the electrodes were perfect text book condition but the threads were wet with oil. The oil consumption is a whole lot worse now than it was back then.

[furtula]

You don't have to take the throttle body out, should be able to just remove the hose clamp, pop the hose and give it a look.

Thought about Italian tuneup?

[Mooly]

2 hours ago, furtula said:

Thought about Italian tuneup?

Hehe, it's certainly not lacking in that department.

It gets red lined at least every other day on average which sounds really brutal but I've started doing this when its not going to annoy anyone more as a matter of trying to keep things clear. If it wasn't such an oil burner then I wouldn't do this so aggresively. So sometimes foot hard down and 1st gear up to the redline, and sometimes 3rd gear joining a motorway for example. Sometimes I will do a couple of miles on the motorway in 4th rather than 6th.

I took the PCV valve out this morning (that's an easy one) and it seemed essentially OK. Free and rattly but I gave it a clean with high pressure iso (isopropyl alcohol). It was pretty clean though.

About 35 miles covered this morning with around 22 miles on the motorway. It doesn't seem quite as bad, noticeably so really. Not perfect but better. I wonder if the Wynns additive and Esso E5 is having an effective. Shell seems to be the one that gets recommended which I'll try next time I think. Its run 99.99% on Esso, latterly E10 

I'm also (and this will develop bad habits if I'm not careful) deliberately not using engine breaking when slowing down just now. That is when it really really smokes (when you come back on the gas) and so I'll try and spare the sensors from that.

 

[TonyHSD]

Does your 1.33 engines has an egr valves and small holes inside the intake manifold similar to 1.8 hybrids? 

The theory is that at certain speeds and loads let say 25% engine load the throttle plate gets closed and the air supply goes via egr only. Since the egr air passages are blocked and very limited there is almost no air supply while engine creates a strong vacuum that fully opens the pcv and sucks oil from there, a lots of oil that gets burned. This theory makes a lots of sense in 1.8 2ZR-XFE and when I was opening and cleaning my throttle body and replaced pcv first time at 60k miles I found a lots of oil was seating at the bottom of the manifold below the throttle body. At that time the car has had no oil consumption. I am planning soon revisiting and changing pcv, cleaning intake manifold and egr system. We will see what I will find now, over 100k miles since last check and clean. 👍 Pcv valves may look good but I believe after some miles it is a good idea to get changed for new as it’s basically a spring loaded valve that spring will get tired and may not open or close properly. Those pcv valves only gets blocked on neglected engines with a lots of carbon buildup. 

[Mooly]

1 hour ago, TonyHSD said:

Does your 1.33 engines has an egr valves and small holes inside the intake manifold similar to 1.8 hybrids? 

I honestly don't know on that one Tony.

I tried blowing through the PCV valve after cleaning it and find you seem to have to blow fairly hard before it snaps shut. It was free 'free rattling' when given a shake, in fact it sounds like there is a weight in there, perhaps to pre-bias the valve. It was all much cleaner than I expected.

1 hour ago, TonyHSD said:

Those pcv valves only gets blocked on neglected engines with a lots of carbon buildup. 

Well neglected it is not but carbon build up is one of the listed symptoms of the oil burning issue.

One other thought I was whether it was a dodgy fill up of petrol at the time. I'll only know that by running it to empty now and then trying the Shell V Power as a test. 

 

[Mooly]

This is an interesting read:

Toyota Auris 2010 - TR 5dr 1.33 VVT-i - Carbon Build EGR Valve after 4 Years | Technical matters | Back Room Forum | Honest John

[TonyHSD]

46 minutes ago, Mooly said:

This is an interesting read:

Toyota Auris 2010 - TR 5dr 1.33 VVT-i - Carbon Build EGR Valve after 4 Years | Technical matters | Back Room Forum | Honest John

That’s an interesting read.  Thanks.
I used to have often short knocking on cold starts previously but since over a year now maybe two I only had these happened very occasionally. The things that changed with the car is that I started to use E5 99 mostly and sometimes exclusively Tesco momentum. I know it’s a supermarket fuel but it’s classed as premium at slightly higher price and I can feel the car is driving much better, engine has more power and it’s quieter than if I use e10 from any other petrol stations. When I first cleaned my egr system was bad, not as bad as I had seen in other cars but was clogged with hard black matter, carbon or whatever is called. Since the clean up the car drives better and those engine knocking almost completely disappeared. Now I had traveled over 100k miles and will soon open to check and clean again just as precaution, I don’t  get any symptoms of blockage in the egr like I had before but just to be on the safe side. Will put a new pcv at the same time. 
It seems like you do have an egr similar to mine and if it was me I would be opening and checking and cleaning plus new pcv replacement just to see if this will make any difference. https://japancars.ru/index.php?route=catalog/toyota&mdf_id=7063&area=EU&cat=166510&blk_id=2501
 

[flash22]

Pull the plugs, a fouled plug will not fire cleanly a worn plug will also fail under load

when were the plugs last done ? If they haven't been changed, they are overdue at 94K - it may also be running the old part number plugs - what Toyota and Denso changed the spec of due to poor running especially when worn

 

SC20HR11 replaced with SC16HR11 (hotter plug), the 1.33 runs better with Denso plugs

[Mooly]

2 hours ago, TonyHSD said:

The things that changed with the car is that I started to use E5 99 mostly and sometimes exclusively Tesco momentum.

I think at this point I'm going to at least wait until I have another fill-up with fresh fuel and I'll use E5 as a trial. At the moment its no more than half and half in the tank plus the Wynns.

Thanks for that link, really useful.

1 hour ago, flash22 said:

when were the plugs last done ?

Here and with a picture😉

They are the later hotter plug

 

[flash22]

Pull the plugs and see if they are fouled, and look for track marks on the porcelain, check the boots on the coils and make sure the plug wells are dry (rocker cover gasket/seals)

do a few WOT snaps, and see if it returns to idle or stumbles/falls flat on its face

[Gray86]

Shell v-power is very good at cleaning internals (they are boasting a new formular too now), as is BG44k which is the most potent injector / fuel system cleaner 

[TonyHSD]

Throttle bodies on any car gets dirty and ready for cleaning as quick as 50000 miles or so. In some cars it’s or a problem at all and they can keep going for a lot more for others it does cause some problems like rough idle, lumpy drive, engine fluctuations at low rpm. Simple clean can sort most of the issues. Maf sensors usually always look clean however they have a thin oily film, a shoot of specialist spray will make them even cleaner. 

[Mooly]

Thanks folks. I'm going to run the tank down before going further just to be sure nothing weird iis going on with the fuel and to let the additive do its thing.

11 hours ago, flash22 said:

Pull the plugs and see if they are fouled

Would the crush washer seal again if they were put back? 

Also remember it doesn't do this problem from stone cold, its only after a couple of miles it starts to become apparent which is why I was thinking a sluggish 02 sensor. Starting is absolutely instant.

18 minutes ago, TonyHSD said:

Maf sensors usually always look clean however they have a thin oily film, a shoot of specialist spray will make them even cleaner.

I was surprised when I looked at mine. There was nothing on the internal plastic part that is in the airflow. I wiped a finger on it to see and nothing. I really couldn't believe it tbh but I still gave the sensor elements a good squirt with iso (isopropyl alcohol).

[flash22]

Once up to temp it will go into closed Loop so uses both sensors to trim the fuel, watch the fuel trims and o2 voltages to see what's going on

 

[Mooly]

So...... the story so far.

 

On 4/14/2023 at 6:50 PM, flash22 said:

Pull the plugs and see if they are fouled, and look for track marks on the porcelain, check the boots on the coils and make sure the plug wells are dry (rocker cover gasket/seals)

It worse than that Jim. Boots, plug wall etc etc perfect pristine condition. The plugs were in a shocking (bad bad bad doesn't even touch the sides) state. These were genuine Toyota plugs bought from Mr T and only half way through their life.

I waited until I had new before even looking (good job as it turns out) and ordered from Opie Oils (brilliant service and way cheaper for the Denso's than Mr T was 4.5 years ago)

Some scary moments this morning, not least because it wouldn't start after replacement... keep reading.

The insulators on the old plugs have started to fail... they are just absolutely shot on three of the four plugs. The pointed Iridium tip looks like it has had a rasp on it to file it down. When I changed these at 60k the 'original from new' (and the cooler 20 heat range ones) looked perfect in the tip and insulator department. The centre electrode was still pin like.

I hope the insulator damage hasn't caused any valve/piston damage but it seems to be running well.

 

 

 

 

So new plugs fitted and tightened as per the fitting instructions with each plug which do not give a torque setting but give an angle tighten instead. 1/4 to 1/2 turn, presumably from as tight as you can initially get them with fingers.

I turned them 1/3 of a turn from finger tight.

Job done and... it wouldn't start. Turned the key, seemed to fire and then the starter just seemed to spin for about 3 seconds even after releasing the key. Panic as you do. Try again. Same. It seemed to be spinning fast... think... it's like there is no compression.

Have I got the plugs tight enough?

Think logically as I haven't screwed anything up. I was super careful. All I have done differently this time is angle tighten and not use a torque wrench. No torque figure is given. 

Out with the torque wrench that only goes down to 28 N/m which is a bit higher than the max figure I researched last time. As back then, I wound the wrench a little below its minimum marked values. Hmmm, there's a lot more turning needed to get the wrench to click.

Phew... it fires up and seems so far to be running very very smoothly.

Question. What did I do wrong or misinterpret with the angle tightening? Everything hinges on how tight they are before you decide to do the required angle. I used as tight as I could by hand gripping the then and long plug wrench.

I also think I will switch to Shell E5. Previously I've 99.5% used Esso E10

[flash22]

Looking at those plugs, it's running hot or very lean, I would flush the cooling system and change the stat - I take it the fans kick in as they should

Take a look at the fuel trims and CTS readings

[Mooly]

Thanks @flash22

The deposits seem to be ash from what I can glean from looking at various images of plug problems. Cause in my case would surely be the oil burning.

I also wonder now whether the hotter plugs Toyota switched to might be OK for 99% of users who do primarily short runs but actually might run too hot under high speed higher load running which would be me.

Maybe I need to accept its time to start looking to change although hopefully it will be good for a while at least now.

2 hours ago, flash22 said:

I take it the fans kick in as they should

All seems OK in that area. Temp gauge never ever goes over normal under any use.

The idle speed is an interesting one. It was OK before and rock steady but the new plugs have triggered a new 'learning cycle' and the revs are higher now but I think more how it should be.  They come down to around 1100 rpm and then smooth fall to about 950. When the A/C kick in it idles up as it should. The last week or two and the revs have been a bit low (despite ECU reset) at around 800 (barely) and the idle up period was not very marked. It all seems a lot better, more normal to how it used to be now.

Oh yes, one other thing. I'd also noticed a definite raspy noise under low to mid range revs under moderate acceleration, again just in the last few weeks and that has gone now. It wasn't really like an exhaust noise, more like induction noise of some sort. Perhaps related to misfiring seeing how bad the plugs were.

These were the originals at twice the mileage:

https://www.toyotaownersclub.com/forums/topic/186870-133l-1nr-fe-engine-current-spark-plug-recommendation/?do=findComment&comment=1492618

[flash22]

Those plugs are a mix of symptoms heat, lean, detonation, oiled and ashy (possible fuel contamination ?)

[TonyHSD]

The results of oil burning and perhaps E10. This e10 it’s not a good one. I can feel the engine sounds bad accomplish by tiny vibrations and weak performance immediately after I fill up with it. Fill up with E5 from Tesco and the car drives and sounds much better. 👍

[Mooly]

3 hours ago, flash22 said:

Those plugs are a mix of symptoms heat, lean, detonation, oiled and ashy (possible fuel contamination ?)

Could be. My ancient Haynes book on engine management has a page of pictures of plugs and the cracked insulators are said to be caused by detonation. Now detonation is a listed symptom of the oil burning issue because of hot spots of carbon build up. What was noticeable as well was the fact that on removing the plugs the threads were not wet with oil like they were at 60K. No explanation for that.   

I must say it felt a totally different drive this morning, super smooth in all respects at this point. I will stick with the E5 at this point though.

I would still like to know what I did wrong with the angle tightening. Obviously my starting point was from far to low an initial tightness but they were as finger tight as I could get them. Where did I go wrong?  

Which reminds me and this is totally unrelated... on page #2 (on my PC) is a Podcast on petrol and E5 vs E10 and on page #5 is one on EV's vs petrol. Its a BBC do-dah. Its a good listen.

Sliced Bread presents...

[TonyHSD]

4 minutes ago, Mooly said:

Could be. My ancient Haynes book on engine management has a page of pictures of plugs and the cracked insulators are said to be caused by detonation. Now detonation is a listed symptom of the oil burning issue because of hot spots of carbon build up. What was noticeable as well was the fact that on removing the plugs the threads were not wet with oil like they were at 60K. No explanation for that.   

I must say it felt a totally different drive this morning, super smooth in all respects at this point. I will stick with the E5 at this point though.

I would still like to know what I did wrong with the angle tightening. Obviously my starting point was from far to low an initial tightness but they were as finger tight as I could get them. Where did I go wrong?  

Which reminds me and this is totally unrelated... on page #2 (on my PC) is a Podcast on petrol and E5 vs E10 and on page #5 is one on EV's vs petrol. Its a BBC do-dah. Its a good listen.

Sliced Bread presents...

The fuel might be the culprit. Here I have my plugs changed last year at 60k miles interval. As far as I remember I was using mostly E5  99 momentum from Tesco. I did switch to it when we had moved from e5 95 to e10 95 September 2021 .
 The plugs also has rusty threads similar to yours and this might have played a role for not been tightened well first time. These has 17Nm by the book, although I always been doing them at at 25Nm by the old standard. 

[flash22]

The plugs have crush washers, if you don't crush them you can lose some compression and suck in air, leaning the mix out

oem spec for the plugs is 20 Nm or 15 ftLb