[Corsa B 1993-2000] Stuttering at low engine speed (Idle)

[Bowden]

Solved: See #1 for syptoms, and #10 for fix

Corsa B 1.0 Wreg 2000, 54k miles.

Hi all,

Just drove about 40-50 miles home with the car stuttering when slowing down. Almost perfectly fine and a steady constant speed and acceleration.

But when slowing down the light comes on, and most the time at idle, then when using the throttle it stutters at steady rate (see vids).

About 3-4 weeks ago, it was running fairly low on oil (topped up by 2 litres), I know my bad. But oil light didnt come on. I only noticed because it sound like a diesel...

As you can hear in the vids, its very 'ticky' and the stutter is steady. And you can see it revs freely when I open throttle fully. Best to watch on pc, mobiles don't have great quality sound.

Exhaust Note

You can actually see the engine rocking back and forth on each stutter
Engine Bay tick

Replaced the Crank Sensor... No Change.

[Taurus]

There isn't much to go on from those video clips. Those 3 pot engines are always prone to vibrations as they are inherently unbalanced - it sounds like the timing chain may be the cause of it but you can't tell for sure off a video clip. Get hold of a big screwdriver, put the tip to the timing cover and the handle to your ear, then you can listen to the internals easily. Beware of moving parts of course. Move the tip around to various other parts of the engine (eg camshaft cover) to check for any odd noises.

You say the 'light comes on' - do you mean the engine management light, if so get the codes read. (Day out in Chester? I'll put it on opcom for you if you're in the area.)

I've known the 3 pot engines to never be smooth at idle, especially the later ones, but the first thing I'd do is to whip the plugs out and have a look at the business end of them.

If you ran it seriously low on oil there is a possibility of camshaft/lifter damage - which is why I'd listen to the cam cover as well as the timing chain.

[Bowden]

Thanks taurus,

I did think earlier; why the hell havn't I looked at the plugs yet. Should have been the first place to look :facepalm:

The 3 pot has always been a shakey engine, but the idle has always been consistant until now. Well I say idle, low steady revs.

Sorry yeah, EML. And cheers, if I was planning on a day in Chester I would take you up on that, but don't really want to stray out of Telford at the minute. I will get the codes read at a garage somewhere, shouldn't cost to much for a 10 minutes job. As long as they don't round up to an hour.

[Taurus]

Bear in mind you can buy Opcom for less than most garages charge for diagnostics - you just need a laptop to run it on.

[Bowden]

Yay or Nay?
eBay Link

Cheapest one I can find with decent delivery time.

[Dave]

Yay, thats pretty much what I bought.

[Bowden]

Cheers!

Looked at the spark plugs, they all look fine to me;


Appart from the red tip, but that could just be the photo. Don't remember seeing it that red yesterday when I took them out.

[Taurus]

Fuel additives can give red colour to the tips. It might be a bit on the lean side, but I'd wait until you've read the codes before doing anything further.

[Bowden]

[Bowden]

Link

Here are the pins in question;


And, I think you need to sand the sides of the pins, because that's where the contact is actually made;


These took a while to sand (about 30 mins), as they are in an arkward place and you need to sand them until they are a nice copper

[Taurus]

Glad it's sorted - just worth noting that on these disconnecting the battery doesn't clear the codes, that only works on the older models. So the code will still be logged in there and will be present if you ever get the codes read again. You'd need a code reader to clear the codes on those.

[Bowden]

Right okay, I will keep that in mind, incase I need the codes read again.

Is there any reason why the problem still occured once it was cleaned out, but then it 'fixed itself' after sitting for a few hours?
My guess is the ECU was replicating the issue for some reason