Clio 3 1.6 16v (K4M862 VVT) strange problem

[bgdy12mst]

Hello, I'm here with a big problem. My car is a Clio 3 GT 1.6 16v 128hp engine K4M 862.
The first start of the engine sounds like that (check video -> https://www.youtube.com/shorts/8Z6y-VFxwSI), the revs oscillate and the sound of the engine is weird also the car fails to pass the emission test in my country (like the UK MOT).
The car in the video is revving alone without pressing any pedal.
Some days ago, I was to someone with the original Renault tester and I don't have any bad parameters, all things are good, with no misfire percents and no ECU errors. He checked also the oxygen sensors and there both are fine. So, he told me that there are 2 probably causes:
1. intake gasket - Maybe the car draws some fake air, but the problem is why after a maximum of 1 minute of revs oscillating all things are ok and the car can be driven well. This should have happened with the fake air all the time, so I think it's not a problem, I think.
2. solenoid? - The guy with the tester told me that I should change the solenoid with the dephaser pulley which is changed 1 year and 10 months ago with the timing belt and water pump in the same time (and after that change, I didn't make more than 7000 km with the car). I also started the car with the solenoid plug removed and it's the same.

Does anyone have other ideas? Or has anyone else had this problem?
After a maximum of 1 minute of letting the car idle, the idle is perfectly where it should be and the car has no more problems until the next day, I can start and restart engine all the day without any problem. And after it warms up, everything seems ok, and I can't figure out if I have any 'lack of power'. I also tried to disconnect the solenoid when I start the car at cold to see if it behaved differently, but it's the same.
Also, after that 1-2 mins maximum of rough idling, I can turn it off, wait for it to cool down, and if I start it the same day, the problem no longer appears, but the next day it appears again.
What I managed to figure out is that I have the value -23 on OBD2 at the LTFT sensor, and also the STFT is oscillating negative without reaching a value of 0. So, a large negative LTFT value is telling me there is uncontrolled/unwanted fuel being added to the mixture somewhere that the ECU needs to remove (thus negative LTFT) in order to get closer to the ideal 14.7:1 expected in the exhaust. What do you think? In 5000 km driven I didn't get any error on ECU.
If someone has any ideas... both O2 sensors are perfectly working
I would have left the car as it is, but the problem with the emissions test makes me do everything possible to fix it.

 

[bgdy12mst]

EDIT: In the video, the car is it accelerates by itself, without me pressing any pedal.

 

[kurai]

From your description/testing.. it may also be a small airleak, when the engine warms up, expanding it seals and runs well.
Its not picking up many rpm.. so it may be something small.

If it was my car.. I'd check theese things:

-Map sensor O.R. (they are known to leak sometimes)
-spray with a carb cleaner spray or compressed air near intake joints and observe results. Any bigger fluctuation of rpm may indicate a leak.
-cheching the side of throttle body, there is usually a part (surely on the gokd side on mk2, not sure if needing to remove airbox on mk3) showing the return spring and the shaft. You can see if it stay still or if it moves. If its still it may be an air leak, if it moves it may also be something related to it. Maybe even the carbon canister solenoid.

Those are the first 3 things I'd check.
I had a similar engine with a similar problem driving me nuts some years ago.. and not only me.. 4 garages.

 

[Ferdinand]

I agree with kurai, his first point in particular, i think its a bad mapsensor.

 

[TngRx]

Hello everyone,
I see this post years before its creation but... Did you find the problem? I have a really, really similar one (bad idle, very negative LTFT) and the mechanic doesn't find the solution...
Thanks!

 

[Beepboop]

Hello everyone,
I see this post years before its creation but... Did you find the problem? I have a really, really similar one (bad idle, very negative LTFT) and the mechanic doesn't find the solution...
Thanks!

So did you get any further? I’m having the exact same issues.

 

[TngRx]

So did you get any further? I’m having the exact same issues.

What has been done on the car : dephaser valve, dephaser pulley, spark plugs, MAP sensor, tried a brand new throttle body, and lately a head gasket machining (yes!). It helped for the consumption when engine is loaded, but the idle remains horrible. Renault did a full diagnostic of all ECUs : no DTC at all.
Last week end, the engine nearly stalled all alone when I was putting something in the trunk. And I sometimes stall it myself, at green light or when parking, even though I know the car's behavior... Next step, the workshop wants to try a new ECU. At it keeps looking for the solution. But it started 6 months ago. I have not much hope anymore actually.

 

[Beepboop]

What has been done on the car : dephaser valve, dephaser pulley, spark plugs, MAP sensor, tried a brand new throttle body, and lately a head gasket machining (yes!). It helped for the consumption when engine is loaded, but the idle remains horrible. Renault did a full diagnostic of all ECUs : no DTC at all.
Last week end, the engine nearly stalled all alone when I was putting something in the trunk. And I sometimes stall it myself, at green light or when parking, even though I know the car's behavior... Next step, the workshop wants to try a new ECU. At it keeps looking for the solution. But it started 6 months ago. I have not much hope anymore actually.

Hey thanks for the reply.

Hmm sounds like you did a lot of the same things I did which include; throttle body, evap purge valve, map sensor, IAT sensor, coolant temp sensor, vvt solenoid, knock sensor, camshaft sensor, flywheel sensor, spark plugs, ignition coils, alternator, both o2 sensors, all fuses, mass cables. Some were done to fix the issue, some were just maintenance because I liked doing it.

I do have P0300 code coming back every now and then, and a P0420 now. P0300 started after windshield wiper hose broke and got fluid all over the engine compartment and into the coils. Switched those out including plugs, but still P0300 is there once every few months.

LTFT reads at about -20% and I have the weird rpm fluctuation thingy on warmup too. Went into the cylinders with a borescope which showed surprisingly clean cylinders. No dirty valves. Compression test was not the best, but ok enough for age and mileage, at the low point of reference value.

So that leaves me with the injectors/fuel system unchecked. Also want to rule out a flooded evap canister. Cat is obviously old but not gone according to o2 readings. So my guess for the P0420 code is that it’s secondary to the main issue. Going in with smoke machine to see any cracks in the exhaust system or maybe somewhere else. When I’m taking out the injectors I will also check the PCV to see if that’s clogged but probably totally unrelated anyway…

Also, I’ve noticed the o2 sensor heater resistance being at 0ohms all the time, which isn’t the correct value. But not sure if that PID is a misinterpretation because that value shows for both of them which would be weird. And why would it do that.. It doesn’t show any open circuit codes.

Putting in a new MAP sensor did make it run a lot better. It kept stalling on me when that sensor stopped working. I made a data log one day and found that after blip of gas it started reading the barometric pressure as if we drove into a hurricane. Anyhow, I bought a Hella MAP sensor, found out this car does not like that brand at all. The Era one works fine.

So you ruled out play on the vvt pulley too, that’s nice.
So yeah, that’s my journey up until now…

 

[TngRx]

Hey thanks for the reply.

Hmm sounds like you did a lot of the same things I did which include; throttle body, evap purge valve, map sensor, IAT sensor, coolant temp sensor, vvt solenoid, knock sensor, camshaft sensor, flywheel sensor, spark plugs, ignition coils, alternator, both o2 sensors, all fuses, mass cables. Some were done to fix the issue, some were just maintenance because I liked doing it.

I do have P0300 code coming back every now and then, and a P0420 now. P0300 started after windshield wiper hose broke and got fluid all over the engine compartment and into the coils. Switched those out including plugs, but still P0300 is there once every few months.

LTFT reads at about -20% and I have the weird rpm fluctuation thingy on warmup too. Went into the cylinders with a borescope which showed surprisingly clean cylinders. No dirty valves. Compression test was not the best, but ok enough for age and mileage, at the low point of reference value.

So that leaves me with the injectors/fuel system unchecked. Also want to rule out a flooded evap canister. Cat is obviously old but not gone according to o2 readings. So my guess for the P0420 code is that it’s secondary to the main issue. Going in with smoke machine to see any cracks in the exhaust system or maybe somewhere else. When I’m taking out the injectors I will also check the PCV to see if that’s clogged but probably totally unrelated anyway…

Also, I’ve noticed the o2 sensor heater resistance being at 0ohms all the time, which isn’t the correct value. But not sure if that PID is a misinterpretation because that value shows for both of them which would be weird. And why would it do that.. It doesn’t show any open circuit codes.

Putting in a new MAP sensor did make it run a lot better. It kept stalling on me when that sensor stopped working. I made a data log one day and found that after blip of gas it started reading the barometric pressure as if we drove into a hurricane. Anyhow, I bought a Hella MAP sensor, found out this car does not like that brand at all. The Era one works fine.

So you ruled out play on the vvt pulley too, that’s nice.
So yeah, that’s my journey up until now…

Interesting, thanks for your feedback. For me, everything started by a thermostat oil leakage which destroyed the dephaser EV among other parts.
It is funny because I never got P0300 before...today... I saw the engine light flashing at a red light during some seconds. It stopped but the stored DTC is P0300.
I will check again the MAP sensor, because mine is a Hella... And after having checked internet, I fear that I installed it wrong (pushed too far down, both o-rings are "in"). The problem is that this shitty sensor always breaks when you unplug it... I will buy another one, out of caution.

 

[Beepboop]

Interesting, thanks for your feedback. For me, everything started by a thermostat oil leakage which destroyed the dephaser EV among other parts.
It is funny because I never got P0300 before...today... I saw the engine light flashing at a red light during some seconds. It stopped but the stored DTC is P0300.
I will check again the MAP sensor, because mine is a Hella... And after having checked internet, I fear that I installed it wrong (pushed too far down, both o-rings are "in"). The problem is that this shitty sensor always breaks when you unplug it... I will buy another one, out of caution.

Wow you just got the P0300?! You’re kidding? Indeed the engine light flashing.. Whenever I get that, it’s always when driving in slow traffic. Well that sucks, sorry to hear that. But all the info makes the story even more interesting because, it could be a coincidence, but I had an oil leak from the thermostat too.

When I just got the car a couple of years ago i went to the autobahn to see how fast it could go. When i got home there was oil on the gearbox and sludge started forming in the coolant reservoir. I was just starting to learn how to work on cars back then so I had the thermostat housing changed at a garage. But they were so unhulpful that I wanted to be able to fix and diagnose most things myself.

The idle surge and sporadic problems started 3 years ago, so could still be an effect of something that happened after the oil leak.

Last year I did the coolant flush and coolant temp sensor change as I started suspecting there might still be gunk on the sensor, but there wasn’t.

Hmm, I will do a double check on all the wires where hot oil could have leaked on. And extra check for exhaust manifold cracks around that place. The o2 sensor wires are somewhere around there too.

So funny to hear about your experience with the car and that it’s so similar. (But I also know it’s driving you mad sometimes). I also broke off the MAP sensor the first time ofcourse. Luckily the throttle body comes off easily. Will look at how far i shoved the MAP sensor in, thanks for the details about the o-rings, i also did not know that. What i did do was fix it in place a bit more as it was very loose. There are 3d printed parts that you can put over the sensor for stability. I now have an Era sensor. Hope that at least fixes the stalling. Which it did for me

Anyway, if I can help you with any data logs or info for you to compare, just let me know. I use the ‘car scanner’ app which actually recognizes this specific car. There are so many values that other apps don’t show. There’s also a program written in Python which mimics Renault Clip. I managed to get it working on a laptop and was able to read all values. But it was so much that I just didn’t even know what to look for. And Renault doesn’t have specific documentation for the reference values. That was a rabbithole i went into DEEP. And will only do again with more specific leads haha.

 

[Brigsy]

The p codes can lead you down the garden path with these, need clip to diagnose correct df codes really. Id be datalogging a few parameters on startup.

Flashing eml is typically faulty injector on clios of this era. With the fuel trims being out, id be looking at them.

 

[Beepboop]

Wow you just got the P0300?! You’re kidding? Indeed the engine light flashing.. Whenever I get that, it’s always when driving in slow traffic. Well that sucks, sorry to hear that. But all the info makes the story even more interesting because, it could be a coincidence, but I had an oil leak from the thermostat too.

When I just got the car a couple of years ago i went to the autobahn to see how fast it could go. When i got home there was oil on the gearbox and sludge started forming in the coolant reservoir. I was just starting to learn how to work on cars back then so I had the thermostat housing changed at a garage. But they were so unhulpful that I wanted to be able to fix and diagnose most things myself.

The idle surge and sporadic problems started 3 years ago, so could still be an effect of something that happened after the oil leak.

Last year I did the coolant flush and coolant temp sensor change as I started suspecting there might still be gunk on the sensor, but there wasn’t.

Hmm, I will do a double check on all the wires where hot oil could have leaked on. And extra check for exhaust manifold cracks around that place. The o2 sensor wires are somewhere around there too.

So funny to hear about your experience with the car and that it’s so similar. (But I also know it’s driving you mad sometimes). I also broke off the MAP sensor the first time ofcourse. Luckily the throttle body comes off easily. Will look at how far i shoved the MAP sensor in, thanks for the details about the o-rings, i also did not know that. What i did do was fix it in place a bit more as it was very loose. There are 3d printed parts that you can put over the sensor for stability.

Anyway, if I can help you with any data logs or info for you to compare, just let me know. I use the ‘car scanner’ app which actually recognizes this specific car. There are so many values that other apps don’t show. There’s also a program written in Python which mimics Renault Clip. I managed to get it working on a laptop and was able to read all values. But it was so much that I just didn’t even know what to look for. And Renault doesn’t have specific documentation for the reference values. That was a rabbithole i went into DEEP. And will only do again with more specific leads haha.

The p codes can lead you down the garden path with these, need clip to diagnose correct df codes really. Id be datalogging a few parameters on startup.

Flashing eml is typically faulty injector on clios of this era. With the fuel trims being out, id be looking at them.

Thanks. I also used Pyren to read the codes. And went to a friend who has Clip so codes are correct. Leaky injector is one of the top suspects. But I don’t think they sell any good replacement, do they? Want to take them out and have them cleaned soon anyway.

 

[TngRx]

Yes, I forgot to talk about it, but my fuel trims are completely aberrants. In idle, STFT is ~ -40%, and LTFT is ~ -20%. But when load is higher, for example on the highway, the LTFT converges close to 0%, and consumption is back to normal (7,5L/100km @ 130 kph). Consumption is very high in urban/secondary road conditions.
I also had a faulty downstream O2 sensor, it has been changed, but the car's behavior remains the same. For sure, this O2 sensor is only there to ensure the catalyst is working...
I brought the car to a Renault workshop especially to get a complete diagnostic, the mechanic tested all the ECUs, and none of them reported any error. Then he said "good luck" to solve the issue...

 

[Beepboop]

Yes, I forgot to talk about it, but my fuel trims are completely aberrants. In idle, STFT is ~ -40%, and LTFT is ~ -20%. But when load is higher, for example on the highway, the LTFT converges close to 0%, and consumption is back to normal (7,5L/100km @ 130 kph). Consumption is very high in urban/secondary road conditions.
I also had a faulty downstream O2 sensor, it has been changed, but the car's behavior remains the same. For sure, this O2 sensor is only there to ensure the catalyst is working...
I brought the car to a Renault workshop especially to get a complete diagnostic, the mechanic tested all the ECUs, and none of them reported any error. Then he said "good luck" to solve the issue...

Datazap

The fastest, easiest way to visualize, analyze, and share your automotive datalogs: for everyone from weekend hobbyists to pro tuners.

datazap.me

Here’s a data log of mine for if you want to see the fuel trims. I didn’t caputere everything I could though. Otherwise there would be too many PIDs. Data speed already wasn’t optimal. You can select PIDs when you click on them. Unfortunately i didn’t capture the time correctly. STFT and LTFT are a little less dramatic than how they were with the Hella map sensor. Everything you mention sounds very familiar.

 

[TngRx]

Datazap

The fastest, easiest way to visualize, analyze, and share your automotive datalogs: for everyone from weekend hobbyists to pro tuners.

datazap.me

Here’s a data log of mine for if you want to see the fuel trims. I didn’t caputere everything I could though. Otherwise there would be too many PIDs. Data speed already wasn’t optimal. You can select PIDs when you click on them. Unfortunately i didn’t capture the time correctly. STFT and LTFT are a little less dramatic than how they were with the Hella map sensor. Everything you mention sounds very familiar.

Do you drive my own Clio ?! It is exactly what I have.

 

[TngRx]

After replacing the MAP sensor (succeeded to unplug it without breaking it !), I thought idle was a bit better. But after some starts, especially a cold start, actually it is similar. So no progress. Are our injectors prone to leaks? Because the lambda measures too much fuel especially on idle, so they are the main suspects. But there isn't one cylinder that's weirder than the others (when disconnecting the coils one by one).

 

[Beepboop]

After replacing the MAP sensor (succeeded to unplug it without breaking it !), I thought idle was a bit better. But after some starts, especially a cold start, actually it is similar. So no progress. Are our injectors prone to leaks? Because the lambda measures too much fuel especially on idle, so they are the main suspects. But there isn't one cylinder that's weirder than the others (when disconnecting the coils one by one).

Sorry to hear that didn’t work.
What’s the mileage on your clio? I’m at 230k km. Had it since 115k. Do you run it stock? Did you change anything about the exhaust system? Mine has the mid silencer deleted by someone who welded it pretty bad. So i suspect some leaks. But nowhere near the cat. Anything else worth mentioning that might sound unrelated for now? Like is it sweaty somewhere? Is it worse right after putting fuel in it? Does it change depending on how full the tank is?

I’ve read stories where indeed the injectors were leaking on either twingo rs or clio GT.
Would be helpful if someone with a clio GT that runs well could make a data log to check their values. I’m not sure what the fuel trims on idle should be. I’m guessing some things could be normal, like running rich on cold start. But to what extent, I wouldn’t know. I’ve also heard that for a couple of cases cleaning the injectors wasn’t enough, because some electrical part within it was broken.

I want to take them out to at least clean them with an ultrasonic cleaner. Maybe I could fit some bottles over the injectors and do a spray test.

But if i take them out I’ll want to change the pcv valve too. And need to order a new gasket. Think I will order the parts today. I really want to fix it this time. Just done the brakes and pads yesterday. But it just doesn’t feel nice when you KNOW something is not right..

 

[TngRx]

It approaches 170k, and I got it when it had 90. It had an oil leak near the oil filter too, but solved. The spark plug wells are relatively clean too.
Yes, it would be nice, because maybe these trims are OK...But I doubt it, because that would mean that the car's development was really done with feet.
I will ask the mechanic his opinion about injectors and PCV next time I see him for the ECU test... On my side, I want to spend as little money as possible on this car, and get rid of it when finances allow

 

[TngRx]

And yes, the car is completely stock.

 

[TngRx]

Datazap

The fastest, easiest way to visualize, analyze, and share your automotive datalogs: for everyone from weekend hobbyists to pro tuners.

datazap.me

Here’s a data log of mine for if you want to see the fuel trims. I didn’t caputere everything I could though. Otherwise there would be too many PIDs. Data speed already wasn’t optimal. You can select PIDs when you click on them. Unfortunately i didn’t capture the time correctly. STFT and LTFT are a little less dramatic than how they were with the Hella map sensor. Everything you mention sounds very familiar.

Do you have a similar record with MAP also? Do you have the same MAP behavior: when you release throttle, MAP is ~20 kPa, but then it settles to >40 kPa in idle.

 

[Beepboop]

Do you have a similar record with MAP also? Do you have the same MAP behavior: when you release throttle, MAP is ~20 kPa, but then it settles to >40 kPa in idle.

I can make a data log for you with that specific info. Just idle and then a couple of times a blip of gas? Or do i hold it for a couple of seconds? Engine warm, cold or both? Excuse me for the excessive questions, but i’d rather have the log be useful for you. Oh the life of working in tech haha.
If i’m going to make a data log anyway, do you have any other requests?

 

[TngRx]

To keep it simple, what is the value of your MAP on idle? I wonder if 40-50 kPa is OK on this engine...
I did a log on my car also (thanks for teaching me the existence of datazap, very good tool!) https://datazap.me/u/tngrx/logs/cmnz4dwns0005l806mlkgyo69

 

[Beepboop]

Datazap

The fastest, easiest way to visualize, analyze, and share your automotive datalogs: for everyone from weekend hobbyists to pro tuners.

datazap.me

Here’s a data log after my drive home from work. I just let it idle and did one short blip at the end since you mentioned it. The MAP value started at about 39 and slightly got higher, but not more than about 42-43 as you can see in the log. I’m not sure if my car does what it’s supposed to do either. But all info is welcome at this point I guess.

I’m starting to think my injectors are leaking. I remember I did a fuel pressure test with my friend, and he said that it was good. But I remember that I thought it was ever so slightly underpressured. Maybe that and a combination of old cat being more ruined by that. Would totally explain the negative fuel trim too.

I’ll have a look at the log you made in a bit and see what your car does. Datazap is awesome indeed glad you like it.