Engine Management light

[jaffa20]

Hi all,

Leaving work today, when i started my 02 1.6 5. The engine management light came on. I checked all the fluids and everything looked fine. It drove fine the whole way home. Smooth and nothing unusual. I switched off the engine a few times while stuck in traffic wishing the light to go away

When i got home, i let the engine cool for a few moments and started up again. Lights all gone. Wondering what could be the problem here. Will probably have to get a diagnostics done if it comes back.

Do you think it's ok to drive if it stays off or should i still get it checked out? Checked manual and they just suggest emmissions or electrical problem so pretty vague.

Apparently when it flashes, it shouldn't be driven and brought to a garage immeditately so hope that doesn't happen.

This happened to anybody before? Thanks for any suggestions guys.

[leamyj]

Might be a loose or faulty wire to one of the sensors..probably 02 sensors.

[jaffa20]

Might be a loose or faulty wire to one of the sensors..probably 02 sensors.

Cheers, that doesn't sound too serious at least.

The 02 sensor seems to the most common issue from researching online. If the light comes on again, i'll get it checked over. Will keep an eye on the fluid levels too just in case. Should be safe enough driving it....i hope

[Amri]

I had a bit of an 'engine management light' saga a few months after I got my mx5.

Light came on while I was on the M50 one day, like yourself, had no engine temp issues, no noises, smells etc, everything was running fine. I called the garage and they told me to come down when it was convenient - it was apparently absolutely fine to keep on driving it as long as it didn't flash or turn red (think it's behaviour depends on the year of the car). If it did, then I was to pull over and get her towed home!

Anyway, turns out it was the speedo sensor which was throwing the fault so I had the part replaced under warantee. On the drive home from the garage, the feckin light came on again!!

To cut a long story short, there is a wire feed that comes from the speedo to the radio console - and somehow when my husband replaced the radio for me (which was around the same time the issue cropped up), he thinks he may have short circuited this, or did something so that it triggered a fault. He removed the new radio and 'fiddled around with it <technical description>' and the light has been off since ... I'll try find the link where he got this information from.

Anyway, moral of the story is that it's fine to drive with the light on, it won't burst into flames like I thought it would Apparently the car goes into 'limp mode' which means it uses default readings rather than those taken from the sensors, o2 or the like, so the worst side effect will probably be an increased fuel consumption, so they told me!

Good luck getting it sorted!

[jaffa20]

Thanks for that Amri.

Hoping the light doesn't come on again tomorrow. Started it a few times tonight and took it for a short spin (always find an excuse ) to see if it came on again and nothing. Hoping it was just a once off thing but if it comes on again, i'll get it checked out and post back re the problem.

[franksm]

Hey - all good advice

The engine-managemen-light (EML) on the '5 is a bit dumb though. It'll come on for simple things like AnneMarie's speedo sensor problem. But it'll also come on for expensive-if-not-fixed-soon things like a bad engine sensot. The light still shines the same, it won't give any better information so you really need to have the error codes read to find out what.

You can tell most expensive-if-not-fixed-soon things by the fact that the engine goes into limp-home mode - it might backfire, misfire, run rough or not rev over 3000 rpm. The expensive bit is that running like this kills the catalytic converter, because limp home mode is really the engine being given a richer fuel mixture to run on. Richer fuel mix = more emissions = very soon, a burned out cat = expensive