Is200 Misfire Juddering Cylinder Misfire Codes Possible Fix

[abidali786]

Hi all.

I've had a problem with my W reg is200 for a few days now. Intermittent juddering and when it does the engine and trc warning lights come on.

Greenflag checked the codes and it said cylinder 5 misfire. Cleared the codes and it worked fine for a few miles and it juddered again - read the codes again and it said multiple misfire cylinder 1 3 and 5.

Having read endless posts on here where people have changed the spark plugs and coil packs with no results I thought it would be best to sell the car as spares or repairs.

However I have noticed in the time I've had this fault I only have the juddering and warning lights issue when I have less than a quarter tank of fuel. When its filled up higher I don't get the problem.

I've spent all day testing this theory and so far it seems that the only logical reason it judders.

I'm goinf to run it above a quater tank of fuel for another few days just to be absolute sure.

would be great to know if those who have had this issue and replacing coil/spark hasn't worked- how much fuel they had in their tank.

I'm guessing on mine it might be a blockage somewhere. It runs like an absolute dream when the tank is above a quater.

[abidali786]

Also just to add. I only got the problem when it was warm. But whilst ive got more fuel in the tank no issues at all.

[ChrisIS200SportTTE]

Don't sell the car as spares or repair because you have a misfire code. And I don't understand where you are getting the information that changing coil pack doesn't normally fix it. Quite the opposite, it's more than likely going to be faulty coil.

Pull the coil from a cylinder that is misfiring and from a cylinder that isn't misfiring. Swap them. If the code moves with the suspected faulty coil you've determined the coil is faulty.

The fuel theory I've never heard before and I can't see how it's gonna make a difference. I've seen many many misfires on IS200's and 95% of them a cured by coil packs

[ChrisIS200SportTTE]

If a blockage in the fuel line or the fuel pump was faulty then it wouldn't matter how much petrol is in your tank

[abidali786]

Initially it showed up as cylinder 5 misfire.

I swapped cylinder 5 and 4 around. The light came back on ans it said cylinder 1 3 and 5 misfire.

Weird thing is that it drives perfect providing I have atleast a quarter tank of fuel - no juddering - no warning light.

[ChrisIS200SportTTE]

Well hate to say this but multiple misfire codes that don't move with the coils could well be collapsed/blocked pre cats. Again, seen it a few times, random misfire codes, poor running, juddering.

I had a mate who's 200 kept throwing misfire codes and we couldn't get to the bottom of it until one day we took the manifold off as we were running out of ideas and the two pre cats on the manifold had completely collapsed blocking the exhaust 80ish%, creating back pressure, misfire codes.

[ChrisIS200SportTTE]

And yes before somebody says it, you would expect a Cat below threshold code but we didn't get it. Just misfires on different cylinders.

[clifton 94]

hi i agree with chris check the pre cats we had a merc 320 come in when we code read it come up with misfire 1 3 5 and we found the cat broken on one side and blocking the exhaust but this does not explain the fuel tank fixing the problem

[abidali786]

Thanks guys. I've ran it for a week and it only did it when low on fuel. Really weird. Anyway as it's only an £800 car I've sold it for £550 with the problem and bought another is200.

It didn't seem worth throwing money at.