Engine Light On, Answer needed please!

[ZeV]

Hello all, i have 3 error codes on my MG ZS 180 at the minute, they are as follow

1.P0141 - O2 Sensor Heater Circuit Malfunction, Bank 1, Sensor 2
2.P0131 - O2 Sensor Circuit Low Volts, Bank 1, Sensor 1
3.P0171 - System To Lean, Bank 1

I'm hoping to get it sorted on thursday, but my question is, i'm suppose to be going on a long drive tomoro, about 130ish miles, will it be alright to drive in it with these fault's? it starts ok and seem's to run ok apart from the idle racing abit. Any thought's? p.s need an answer a.s.a.p or will be forced to let the miss drive me in her Suzuki Swift

[octanejunkie]

Hmmmmm.... Sounds like some issues with bank 1 there...
The racing idle would back that up too. Weak mixture won't do valves and piston crowns any favours. It will run hot, and you may get detonation on the cylinders on bank 1.
Whilst it may feel like its running ok, the combustion process isn't occuring correctly, and you could burn a vlave or melt a piston over a prolonged journey.
With those three faults all affecting the same part of the engine, my advice would be to put a paper bag over your head and let the Missus drive. Lol!

[ZeV]

I just been reading about how could get to hot & damage thing's, bugger, paper bag and bad music it is then lol, cheers anyway.

[Jon Norris]

Originally Posted by ZeV

I just been reading about how could get to hot & damage thing's, bugger, paper bag and bad music it is then lol, cheers anyway.

It all seems to point to the pre-cat lambda sensor, the reference to the heater is the sensor heater that warms the sensor from cold starting, then the lean mixture is controlled partly by the same sensor (ECU Temp sensor also when cold) once at running temp it alone adjusts fuel

[jdhturner]

Engine management is not my thing, however, it seems to me that if the O2 sensor is knackered, then the "System too lean error" is meaningless.

I'm not saying it's safe to drive or it isn't, but I would hope the ECU is designed to fail safe and use a sensible fuelling policy once a fault is detected. Sensors should only be required for optimum running.

[Jon Norris]

Originally Posted by jdhturner

Engine management is not my thing, however, it seems to me that if the O2 sensor is knackered, then the "System too lean error" is meaningless.

I'm not saying it's safe to drive or it isn't, but I would hope the ECU is designed to fail safe and use a sensible fuelling policy once a fault is detected. Sensors should only be required for optimum running.

Standard lambda's (Narrow band lambda) opperate on 0-1v with only 3 basic signals, rich, ok and lean, as it states in the error message it points to the sensor which must have died with a set position (or resistance)and for not so serious faults the engine management light wouldn't even come on, but yeah your right the lean issue could have just been when the sensor died or gave an irratic reading because of the heater section going bang, either way it points to the sensor

MG ones are about £125, take them out of the MG box and they are stamped Bosh, if you buy a Bosh one they are only about £65

[ZeV]

Well i'm not going to risk it either way, false reading's or not. I did go for a spin in it today and the engine temp was ok, could smell petrol a fair bit though. I ended up under the car looking for the sensor, looks easy enough to remove the actual sensor, but the cable runs off up into the engine bay and looks really hard to reach.

I'll see what the garage is going to charge me, if it's to much i'll go buy the sensor/sensors myself then they can just fit em for me.

[ZeV]

So i got the garage to put 2 new sensors in which should solve that problem but they fount another problem, something to do with a set of valves are stuck open, but they don't have much of an idea how to fix it they said lol, so does anyone here have a clue?

[minesarover]

What valves give us a clue ?

[ZeV]

Originally Posted by minesarover

What valves give us a clue ?

Erm, i'm not sure he didn't give me much to go on but i'm guessing the 4 on top of one of the cyclinders lol

[Julian.heap]

I think he is meaning the V.I.S valves are stuck open,can't be the inlet and exhaust valves inside the engine coz if they were the engine would not run or it would misfire badly.

The V.I.S (veriable intake system) valve motors are prone to sticking or malfunctioning, they can be refurbed or replaced. The open up some valves in the plenum chambers which allows more are to be drawn in, there by giving more top end power.( think thats how it works's not sure if i'm right, long time since i've worked on a ZS 180)

You can tell if the VIS motors are not working as you a rattle from the inlet manifold or a lack of power somewhere in the rev range (can't remember if it's top or bottom of the revs as i have not driven a ZS 180 in a long while.)

[ZeV]

lol i know that problem because i changed my inlet manifold last year, so i hope it's not broken yet again, last time the valve's actualy broke and wer rattling away, so this time if it's just the VIS motor gone, do you think i could swap them for the ones in my old inlet i still have in garage? - that or just take the ones out that are on the car and give them a good clean.

[Julian.heap]

Originally Posted by ZeV

lol i know that problem because i changed my inlet manifold last year, so i hope it's not broken yet again, last time the valve's actualy broke and wer rattling away, so this time if it's just the VIS motor gone, do you think i could swap them for the ones in my old inlet i still have in garage? - that or just take the ones out that are on the car and give them a good clean.

Maybe worth trying to clean the motor's if not yeah fit the ones you have in the garage.

[ZeV]

Ok will do when i get chance, for the record the code is

P1472 - VIS 2 Valves Constantly Open

Correct me if i'm wrong but doesn't the VIS motor control a rod that open's and closes 3 valves, so how can 2 be open but not the other one?

[sonic_160zr]

Its probably refering to either the Balance or Power motor rather than the specific valves. There should be a "kick" at about 3k revs and again at 4k depending on the throttle pedal position.

If you are eating through the VIS motors as quick as it seems you are it might be worth looking into fitting an oil catch tank to stop some of the oil that is returning into the inlet becoming a grinding paste for the VIS motor mechanisms.

Check your air filter and induction system for oil. If there is a substantial amount I would deffo look at getting a catch tank fitted. A new set of VIS motors is going to set you back about £140




Cheers,
Matt

[ZeV]

Originally Posted by sonic_160zr

Its probably refering to either the Balance or Power motor rather than the specific valves. There should be a "kick" at about 3k revs and again at 4k depending on the throttle pedal position.

If you are eating through the VIS motors as quick as it seems you are it might be worth looking into fitting an oil catch tank to stop some of the oil that is returning into the inlet becoming a grinding paste for the VIS motor mechanisms.

Check your air filter and induction system for oil. If there is a substantial amount I would deffo look at getting a catch tank fitted. A new set of VIS motors is going to set you back about £140




Cheers,
Matt

I use to notice a kick, but not so much anymore, but that might be just cause i'm use to it now.

As it happens, i put a new induction kit on not long ago, a custom jobby but it does the trick and sounds wicked, didn't notice alot of oil, a little bit in the throttle pipe but nothing major, think i will either replace the VIS motors or the whole inlet again when i got the cash.

[sonic_160zr]

Originally Posted by ZeV

I use to notice a kick, but not so much anymore, but that might be just cause i'm use to it now.

As it happens, i put a new induction kit on not long ago, a custom jobby but it does the trick and sounds wicked, didn't notice alot of oil, a little bit in the throttle pipe but nothing major, think i will either replace the VIS motors or the whole inlet again when i got the cash.

No need to replace the whole lot. Just replace the VIS motors and fit a catch tank. Will still a lot cheaper than replacing the inlet. I would advise getting a VIS motor indicator (a guy on theMGZS.co.uk is selling some) but he is only doing one more batch so get in there quick if you want it. Well worth the dosh as the lights will show you exactly when the motors open and close the valves so you can tell straight away if one of the motors stop working properly.




Cheers,
Matt