K12 Engine Light on and over Revving- Help!

[Lucyd123]

Hi there,

I have a K12 1.2 2006 Micra and am having some issues with the engine light. Early 2016 the engine light turned on and the car was jumping/kangarooing when the engine warmed up. I took it to a garage to get it hooked up to diagnostics and it was showing that the lambda sensors were at fault. I had them both changed and the car ran fine after.

Last month the light came back on again, back I went to a garage and the fault code is showing a lambda fault again. The car isn't jumping like last time, instead it seems to be over revving ever so slightly and when I put my foot down on the clutch to change gear, the revs stick at 1500. The garage I took it to reset the engine and turned off the light and said to see how it goes, if it came back on he suspects it might be the throttle. The light has come back on again and the problems persist.

Has anyone else had any experience in this? I know throttles can be veryyyy costly and don't want to pay out if it doesn't fix the problem. Any help would be massively appreciated!

Thanks,

Lucy

 

[chriswills]

Get them to check the fuse for the lambda sensors,it's in the ipdm fuse box which is under the passenger headlamp. Is a frequent issue on mine. Also ask them to test the Mass air flow sensor which is the sensor on top the air housing on the top almost right in the middle.

Sent from my MotoG3 using Micra Sports Club mobile app

 

[Lucyd123]

Get them to check the fuse for the lambda sensors,it's in the ipdm fuse box which is under the passenger headlamp. Is a frequent issue on mine. Also ask them to test the Mass air flow sensor which is the sensor on top the air housing on the top almost right in the middle.

Sent from my MotoG3 using Micra Sports Club mobile app

Hi Chris,

Thanks so much for the advice. I have just taken out the headlight and checked the fuses myself, all seem to be in tact. Is there any chance the lambda sensors might need cleaning or are faulty?

Re the air flow sensor, I will mention this to the mechanic when I take it in. Would the mass air flow sensor affect the cars revving in your opinion?

 

[Lucyd123]

Also @chriswills I just had a look at the MAF, it's coated in oil. Is it meant to be like this?!

Thanks!

 

[chriswills]

No the m.a.f should be dry and clean. By any chance have the spark plugs been changed recently or the air/throttle housing removed for any reason?

Sent from my MotoG3 using Micra Sports Club mobile app

 

[Machinehead]

I remember a similar think on a vw some years back and it related to the switch that tell the engine computer that the throttle was closed, of in this case wasn't telling the computer. Worth checking some basics before shelling out more money. Also air leak might make the computer over fuel and throw a lambda fault.

By the way the throttle maf should be clean and dry. Is there oil in the air box too? Perhaps some sort of engine breather issue?


Sent from my iPhone using Tapatalk

 

[Lucyd123]

@chriswills The spark plugs haven't been changed since I have had it (18 months) and the last garage I took it to a few weeks ago gave the throttle a quick clean, so I assume he must have taken the housing off.

By air box do you mean the box the air filter sits in? I haven't checked the air filter for oil.

The car is using more fuel than usual too which I guess could indicate an air leak and over fuelling. @Machinehead what is an engine breather issue?

I don't really know too much about cars but I'm trying to check as many bits as I can myself before I take it in on Monday.

Thanks again for your help guys!

 

[chriswills]

I was wandering was wandering the inlet manifold seals maybe perished,has happened with mine before. Never had a diagnostic to check what fault they triggered though. Easily checked by removing the air/fuel housing and they will either on the underside of the housing or sat in the inlet manifold. Replacement for all 4 off Nissan is only about £12

Sent from my MotoG3 using Micra Sports Club mobile app

 

[chriswills]

This is the air fuel box I'm referring to

Sent from my MotoG3 using Micra Sports Club mobile app

 

[Lucyd123]

Did the broken seals cause an air leak or an oil leak? I'm going to hand the mechanic a list of things we have discussed for him to look into for me I think.

 

[Machinehead]

Hi Lucy

As the pistons go up and down they create pressure in the engine, in the bottom, the crank case.

This need to vent and in the old days it just vented to the outside world or a catch can. With emission laws the gasses, witch includes oil vapour, vents back into the air/fuel intake so the small amount of oil gets burnt. If the systems not working right oil can get sucked in to the inlet, hence oil in the airbox and MAF, or leaks can in some designs let air in where it shouldn't! The k12 you have is something I have no experience of but I've run other Euro cars and seen problems!

Just an idea but all the air/emissions pipes need to be sealed and no splits esp in pipes tucked out the way or on any tights bends!

Hth


Sent from my iPhone using Tapatalk

 

[chriswills]

On mine it let air in at the back of the housing where the fuel and air are mixed at the throttle housing,no reason it couldn't then send oil back onto the maf as that is right next to where the inlet manifold joins the throttle housing. Really hope this is of help.

Sent from my MotoG3 using Micra Sports Club mobile app

 

[Lucyd123]

Thanks guys, it is booked in tomorrow morning will pass on what you have said to the mechanic. Will let you know how it goes!

 

[Lucyd123]

So the micra was in the garage for two days, he ran various tests on it and cannot find any fault with the car. Apparently the car is showing 5 different fault codes which he thinks are not relevant to the issues I am having. He has since turned off the light and told me to come back as soon as it comes back on again, to see what code it shows. He didn't charge me anything, which was really nice of him as he didn't have to change any parts.

Literally so frustrating... could it be something to do with the ECU do you think?