Renault Clio III 2007 1.6L 16V no O2 sensor signal

Test drive results with little hose disconnected: no noticeable changes, shaky idling: www.dropbox.com/s/m75336jz2dir957/idling...20no%20hose.png?dl=0

I did swap between disconnecting the hose and pulling off the air filter, but made no difference about the idling.

Only thing barely noticeable is that after the test drive, the car idles smooth (Trims are LTFT -25%, STFT 10-20%): www.dropbox.com/s/2arqau90rjcn5vr/idle%20after%20drive.png?dl=0

This is how it looks when I step on the throttle and feel the car sluggish: www.dropbox.com/s/90peu3c7fktk5sa/low%20...%20-%20lean.png?dl=0

Regarding that hose, haven't found confirmation, but I think that hose is some kind of oil pressure vent. It has very little suction, and the joint where it meets the intake hose has traces of oil indeed.

On the shot where you step on the throttle it starts at 0 on the rear 0/2 ? Was it at 0 or did you just turn on your scan tool?

It seems to be 0... or ALMOST 0... like 5mv maybe. Certainly not the scan tool turned off (See the RPM and intake PSI, it's reporting fine at that same moment)...

What does your psi say with key on and engine off on your tool

About 14.5 PSI ... which matches ambient pressure (1013hpa) (I'm in Cancun, at sea level).

At idle though, the conformity values indicated in Renault's manual are 240mb - 410mb ... but the tech scan tool reads about 440mb.

can you show me what the trims are like at idle with the oil filler cap removed at idle , car warm , is there a lot off gasses coming from the oil filler

Will check as soon as I get the chance tonight and report back...

A few thought so far

Yes that pipe is the crank case breather and the pipe draws in a small amount of air at idle drawing through crank case fumes into the manifold ,this is not any good for spraying in the carb clean but you could put it into the hole you pulled the pipe from in the inlet pipe albeit infront of the throttle body

So there where a number of things from your tests I've noticed
Both 0/2 respond to the fuel and I'm sure if you put it into a good vacuume place it would have shown up better ,including the lean condition .... I think on your car you have a manifold temp sensor ( grey normally ) at the front of the inlet manifold this would be an OK spot to pop it out and do the test

So on the first tests when you added the carb clean the trims where great and you said the only difference you had was the hose was left off ,so with contaminated oil from fuel washing into the oil from misfires it can creat a rich condition ,also on your screen shot of (after drive idle )the long term is at about -23 averagebut short trim is about +8 average maybe ,so this means total is about -15 a lot better that before so I'm thinking some of the problem could be to do with the oil contaminated / maybe high level of oil from fuel ?this I think would be a symptom of the problem but not the main cause ( maybe an oil change with the correct level wouldn't be a bad idea )

On your screen shot of (before grounding rear o/2 )again the fuel trims are good !they end up at 0 long term and -7 short turm ,so this condition seems to change and improve with engine rpm ? But the thing is before adding the carb clean it was showing great trims ..so what changed and how are they linked is what I'm thinking !!

Regarding the noise you recorded when doing the compression test ...valve issue has more effect at idle ,..I wounder if that noise you heard could have been a valve being forced back on its seat ?the only other thing the noise sounds like is the throttle plate shutting ,it's difficult to here on the video what do you think it sounded like ?

I'll give it some thought tonight and catch up tomorrow

www.dropbox.com/s/1xal5jvaqlpio5o/File_001.mov?dl=0 -- last second of that video, sounded like the pop you hear when you pull the thing you push of a syringe... or like when you open a bottle of wine...

Thanks a lot Chris.

goo.gl/photos/9S4QFLHgS82G3pbh9 -- a shot of how it looks with the oil cap off at idle.

When I took off the cap, it sounded like there were some pressure in there. It kind of hissed.

Tried to monitor fuel trims, but for the 2-3 minutes I left it running, I only noticed a slight decrease of rear o2 voltage (say 700mv).

Is that normal? I was afraid of letting it run like that for longer.

Forgot to ask: should I have connected the crank hose back before opening the oil cap? Cause it was disconnected when I took that shot.

Here is what I logged of fuel trims:

Another observation: during the last test drive with the crank hose disconnected, after trying to keep revs high for as long as possible, it was the first time I noticed the rear o2 spent a few seconds at about its expected voltage (480mv). Notice the positive effect on the short term.

Hi so I've been giving this some thought and I can get away from the fact that 1) the problem greatly inpvoves with higher idle and 2) in your shots where you added the fuel and later when you removed the pipe the fuel trims where great ??
Without this I think I would have checked fuel presure probably done a injector balance test and maybe secondary ingnition waveform to see if each cylinder has a lean condition or 1 very rich and others not but at this stage I think we are missing something simple !!


Becouse even at idle you can see before your tests it's been good , I can't see what happened then as I'm not there but something your doing improves the situation!

So I thought of a couple of things to check

1) when engine is warm sit in car and look at fuel trims take a screen shot then increase the revs to 1000 rpm take another screen shot then go to 2000rpm and take the last screen shot , if you can include throttle position in graph also that would be good . This will show if it is only at idle
2) im wondering if the throttle body could be causeing this issue ( this may depend on result from 1) can you remove the induction / air filter pipe so you have clear view of the throttle plate , when you turn ignition on does it open or move and if so how ? Also is there play in the throttle flap ? / loose before you feel the motor restriction. Then with it at idle if there is some play there and you lightly touch the flap to open very slight what are your trims doing at this point?
3 ) with its all back together watch fuel trims and move or press in the areas where you would disconnect the crank breather / small pipe and hold each time to see if stft changes this can be where you rest your hands to support your weight when doing it or on the pipe or I let itself / wires to throttle body / loom ect anything that could have been done to see if you see that change , take your time you may get lucky .. only last week my other halfs car had a bad dashboard vibration at 2500rpm it seemed to come from a pulley at the back of the engine I removed it and it was worn so I replaced it and the noise went for a week . Then returned I remove the pulley and it also now has play in it like the other one but not so noisy when spun so I take it off the car refit and all good for a day but comes back again ,so I remove again and run it without a pulley ...but still there ...long story short the pipe I'm leaning against to support me to lean behind the engine runs into behind the dash it was missing a clip .. let me know how you get on

Crank hose off during tests?

Fuel trims with no hose at different revs:

1200rpm: drive.google.com/open?id=0B5tO7ldKqnssZDJNX01Wczc3MFk

2000 rpm: drive.google.com/open?id=0B5tO7ldKqnssZHJTTUFsU21WNWM

3000 rpm: drive.google.com/open?id=0B5tO7ldKqnssY200OEt2alpQV00

I think what makes the condition improve is the exhaust reading by the downstream o2, that's the one it seems to influence LTFT the most.

I also got a P0300 random misfire in a too lean event (LTFT went below -30% and short term went lean too).

Should I do the test with the crank hose connected?

Also, don't want to make the mistake of jumping off to conclusions, but let me know when it's appropriate to share more details on the last timing belt change job I did with the help of a friend.

In short, we set the timing belt once, and when turning the crankshaft pulley by hand to test for restrictions, there was a hit inside the engine. We checked and somehow, one of the cam tree got out of alignment, so we had to redo the timing and on the second try it seemed to fit. No mechanical restrictions and all reference points seemed in place once the belt was tighten.

And when I started the engine just after that, I got an "Antipollution anomaly" message at the dashboard. It took about 50km driving until it disappeared by itself. During that period was that I sent injectors to the lab for cleaning thinking of a leaky injector or something (car was giving low mileage and some gas smell). I never confirmed it was really the issue, just found some dirt in one of the injectors (cylinder 4 I think).

Let me know if you need any more details...

Sorry this test was with all hoses conected

Sorry for confusion the test with raising idle was with the pipe work conected just to see really when the problem improved as the screen shots showed about 3500 was good so just interested if it improved just off idle ect .so if you would redo that sorry

Re cambelt I would be very interested ,if you get a chance to do the tests first so we know where we are if that ok then please fill me in

Sure no problem. I'm just doing them...