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

You we need new caps again for the end of the cam but otherwise no exspense to have a look , we may have missed something but it's got to be the next logical step !

Will get spare caps to take a look at them after I do the test of disconnecting the VVT valve.

At this point I'm kind of satisfied we've looked everywhere. If we missed something, it'll be a very effective lesson, hehe.

After all, I already took a wiring loom apart for no reason!

Another thing I would have done was a cylinder balance test , I'm guessing you won't have the tools and you say you had the injectors tested

Does your scan tool show your injector pulse width ?im guessing not Just woundered if all where the same for each cylinder

Probably a waste of time but it could narrow the search if you unplugged 1 injector at a time and watched the fuel trims each cylinder should have the same effect but if say a valve got bent you may see a difference and if one of the injectors flows a lot more again you may see a differeance ,just an idea ?

Bittersweet update:

Exhaust camshaft slightly off the mark after setting the crankshaft at TDC.

This time I got help to redo the timing belt, and now it idles smoooooth as a baby's arse

I'm still monitoring fuel trims to see if it relearns by itself. After reassembly, LTFT is -40 and rear O2 reported +700mv but nearly at the end of the first test drive it started settling closer to 550mv.

Manifold pressure is also at about 5.8psi at idle (vs. 6.1) and RPMs are smooth.

If nothing strange happens in the next few days, I'll move on onto fix the coolant leak I have (need a spare thermostat casing) and maybe an oil change is in order as well.

Fingers crossed!

Well good news I see !! :or should I wait a few days for an update on your trims ? im guessing there was no signs of the belt jumping and the tenshioner was still located in its notch ,do you know what went wrong on the timing job for next time ?

That is what frustrates me the most: I have no clue what went wrong during the procedure!

I'm thinking maybe the camshaft gear got misaligned because of the belt being a little bit looser at the top than at the bottom? Even then, I can't explain why didn't that become apparent during the final inspection.

Tensioner looked fine.

I'm really hoping for fuel trims to correct themselves during the next few miles. If not, well, I think I would open a new thread.

(Although I think my mistake with the catalytic converter will come back to bite me pretty soon... damn!).

Chris, thank you very much for all your help and patience with this issue. If you ever come to Cancún, please let me know... I owe you a few pints for sure!

If your LTFT is to change and you've solved the main issue your short turn would have change straight away and shouldn't take long to relearn .from what you say your down stream has leaned out which is a great sign , and all your problems started after the belt change with emissions light coming straight on .and after you mentioned the problem with the timing job it was looking like it was going to be the problem ,well at least we hope so!!!
Re your cat , your bound to end up with a code for that I'm sure ,especially if he removed the entire honeycomb centre .that was really unfortunate there is no way a garage should have offered that as an option !
totaly frustrating trying to solve the problem for you but you know your way round the car quite well now and you know more now than you did before you started !for sure! The biggest thing we need as a diy guy is exsperiance and we can say it's been that it's been tough to help from a distance there are so many variables involved ,have I exsplained it correctly , did you understand it and do it correctly , have I missed something that will send us completely in the wrong direction , is there something completely obvious to a mechanic that I've never seen or heard of ?and it could be something simple ! That's why I love watching scanner d / Eric o and Ivan you feel that your there gaining exsperiance . I've always thought untill you chuck the wrong part at it ,your doing ok ,even if it takes some time and you end up retesting and going back over stuff . I'd much rather make a mistake myself than let a garage make the mistake and still end up paying for it ! Becouse they do , we all do ...
Re cancun I went there in late 96 I think , a great holiday .i went deep see fishing as well as other tourist trips and remember being stuck in the cabin being sick for some time !i caught a few fish but a shark bit most of one of them ..we ended up with just the head
It been great chatting to you ! Give us a update regardless on your trims and how about a pick of the little clio

Oh forget ,well worth doing an oil change and making sure the level is good also cheers chris

So it seems this isn't quite over. Got a misfire again while letting it idle for +3mins.

This time, a P0300 and a P0304.

LTFT doesn't seems to rise above negative, in fact, it kinda got more negative. Although rear O2 seemed to improve. Don't quite understand what happens now.

Too lean at 2000rpm (driving): drive.google.com/open?id=0B5tO7ldKqnssQW1uS183bzh6OEk

Sometimes it seems like it want to correct itself, specially at higher revs: drive.google.com/open?id=0B5tO7ldKqnssT0NGOTZycVlPY0E

And this is what I mean by the rear 02 leaned after the timing belt fix: drive.google.com/open?id=0B5tO7ldKqnssUk5HN25XMXEwMjA (this was letting it idle after a moderate drive -- before the fix it never went below 700mv .. also, intake PSI is much better now).

What I don't like is the trims not fixing themselves. Maybe a code isn't letting them?

Gosh...

Sorry for late reply I was locked out of even viewing the forum on the mobile

So what do we know and what's changed is what I'm thinking ?

The first thing for me is can we be sure the timing is correct now ? Did you set it wrong or is it moving ? I think without a tool to reset the fuel trims I would try disconnecting the battery (completely) both cables and then touch both together both cables hoping to reset the memory just incase it's not relearning . Although I suspect you still have an issue ...
If it was me now I've run the car I would have to again check the timing to be sure nothing has moved and then be able to discount timing being sure that your on compression of no1 tdc and that the marks on the cam sorockets line up .both should be vertical and as you know the other end of the cams the tool will insert

When you reset timing did you check that the vvt sprocket was locket with the cam and not moving

If I checked timing and reset fuel trims and still have a rich condition we are left with 1)any damage due to the previous scan belt changed and it locking up /2) egr gas getting through although you checked this but it could be blocked of with a bit of card in place of the gasket to be 100%sure 3)injectors, is one flowing more than the other , if you can't do the balance test then maybe worth the unplug each injector and watch fuel trims to see if one cylinder is different , if one was, its only gives us direction to a cylinder it doesn't guarantee it's and injector but would lead us to beleave its maybe cause by an individual cylinder

Obviously it you had a scope we could check cam and crank corolation ect ect

When you replaced the injectors where they ever programer ? Is it possible that the Ecu was compensating for a blocked injector and when replaced its now overfueling ? Is my other thought

Well, all of them could certainly be possible (given my previous mistake I wouldn't rule any other mistake by me).

Forgot to answer about the cat: it had two honeycombs, now it only has one...

What I don't quite understand is why only LTFT remains negative, since STFT has now been reaching positive values up to 55%, like it's trying to counter itself. Also, unlike before the cam timing fix, rear O2 is now capable of settling at about 550mv, even while idling.

I expected this to make the LTFT gradually set back closer to 0 but instead if I let it idle for long enough, it goes more negative until it misfires. Both front and rear O2 can be reading lean and still.

Re: injectors, didn't know they needed reprogramming? Certainly the manuals don't indicate anything about that.

What I'm thinking is (in order of ideas):
- maybe there is a manufacturer misfire code making the ECU still trying to protect itself? I haven't erased the codes I got cause I plan to go to techs shop to lend his scan tool again.
- maybe the timing issues did contaminate the oil? Does this make sense? How does such a condition usually behaves at idle vs. high rpm? Cause exhaust and intake manifold pressure have improved noticeably, no doubt about that...
- before the timing fix, misfire codes were of the random kind, after the fix, a cylinder 4 misfire appeared. Why?

What do you think?

Oh so you say the stft has gone positive that's great ! Then maybe no need to panic yet , I know the ltft has many different sells which it will re learn in so different loads and rpm ect so defiantly use the scan tool and there will be a section for emissions related data or fueling data that needs to be reset . Also some fault codes when active will stop long turn changing as far as I'm aware so they need deleting

There's no doubt that it will need an oil change for sure after running so bad for so long

Re cat if it has some cat left in it you maybe ok for bit

Re injectors , I know you have to program some injectors , but maybe not yours? I'm not sure ,just thinking of another problem as running out of ideas when the timing didn't fix it but if fuel trims have gone posative I think it's a relearn / scan tool fix .

I would change the oil and go and delete codes and reset all adaptions I think you should be good

Will do that before even start to think of a possible head gasket problem. According to one of Danner's slides, its a possilble cause for a rich exhaust, and with the cooling fan issue, engine overheated like 3 times, although I immediately turned car off while the temp needle was still climbing hot.

Oh, and a pic is in order but I want to make it after a pending body job next week (or at the very least, a good wash, hehe).

Fingers crossed!

Oh well, so the story continues, and I thought someone might find it useful here.

Turns out, after a couple of weeks of the car running "fine", I started having overheating issues, and the check engine light flashing A LOT. Got codes P0304, and even changing the thermostat (with its housing) didn't solve the overheating issues.

The cylinder head face where the thermostat goes was corroded. The housing had a lot of junk, oil couldn't circulate properly. This should have been a clear warning sign, but just replaced the part (after cleaning thoroughly, of course). No amount of purging the cooling system solved the issue.

goo.gl/photos/rD35Gh4RyYuFQJ9D8

I had to go on a trip and no time to check it by myself, so I trusted it to a friend who has a shop, and they found the cylinder head was just a few millimeters from cracking from the outside, and coolant radiator had a few minor cracks which they repaired.

This is what it looked like: goo.gl/photos/VfYfxmuCpAtYwzUh7

Notice the crack just below the bottom right valve: goo.gl/photos/KhWkh9Q3XcCqkdwW8

So the head was restored at a machine shop, head gasket / exhaust / manifold gaskets replaced, and, of course, timing belt reset.

After the job, there were still heating issues which only got fixed after the original coolant temp sensor was refitted. I think this is due to the spec being different here for Mexico's temperatures as opposed to Europe's.

Now, the issue is that at higher revs (over 3,000), fuel consumptions are very high, with not enough "torque". Not sure if my thinking is right, but given the previous experience with the timing setting, I can see the intake manifold pressure somewhat high (410mb / 6.3psi), and I'm thinking the timing is not quite right.

The guys at the shop are thinking issues with O2 sensors, but I've been there, and I'm not quite convinced. Still, will take the original ones on monday so they can test them. If not, I'll have to convince them that the timing setting could be the issue.

And if you still there ChrisG, I haven't forgotten about that pic of the Clio! Just wanted to wait till that body job was done, but no luck yet with these other issues.