1996 C180 Estate Lumpy/Missfire

[Steve Holland]

Okay have read numerous threads on here in search and have got myself in a right pickle as to what the cause of the problem may be.

Got into the car today (this morning) having driven it around fine for last few months ( except for a gearbox issue - it's not been in limp mode before you ask)

Started no problem but ran very lumpy, spitting in the exhaust and backfired etc.

Driven about for about 10 miles with no change.

I read the forum (searched) decided to spend £20 on new plugs and a new fuel filter.

The plugs where all okay except plug 2 which was very oily to look at...........(search forum maybe a damp isssue?).

Replaced with new item and also gave the carb a good clean generally checked the seals and rubbers thereabouts all okay to the eye.

Started and had a drive and still runs exact same.

If you rev the engine in Park it feels as if it is catching it's breadth (hunting) and quite regualarly if understand my meaning.

Could it be a blocked injector or an electrical issue?

Gearbox related?

Would appreciate something to spend my Easter weekend (not) trying to resolve this issue.

I know the easy option is to get it plugged in for codes etc but at this time I can't as have no equipment and don't really want to drive it anywhere plus with it being an early model there is every chance that it won't show up and to be honest I don't know anyone close that won't charge £40.00+ for the pleasure

Any ideas would be really appreciated

thank you.

 

[tdh-syorks]

Just an idea but I had a similar problem last year.
on the front of the engine at the top remove the small plastic cover and you'll see the cam sensor.
Check the seal isn't leaking oil as mine was, oil had got into the 2 plugs just below the sensor and were arcing a contact. I cleaned out the plugs and re sealed the outer cam seal.
This sorted it.
I'm guessing you have the M111 engine?
Cheers Tom

 

[Steve Holland]

Many thanks for your advice Tom, I assume it is the the plate on top of the cam with the three allen screws and the two pin plug?

I have removed this and cleaned, there was some oil contamination within but I could not locate any area that would require a seal, The two pin connector was given a good wet solvent wash and I sealed around the lower half where it enters the plate body, I also gave the whole thing a good blast with compressed air.

refitted and sadly no difference

With respect to the engine there are small pops and bangs coming from the black collector box beneath the carb manifold.

The engine at steady high rev coughs or hunts for breadth about every 3 to 4 seconds enough to make the engine twist in the bay if you understand my drift?

I have rechecked the plugs and the same plug looks a bit sooty ( no sweep jokes please).

Would it be worth dumping in Red ex in the plug hole or some Injector cleaner or maybe removing the injector and cleaning if it's possible? (how easy?)

Also as an aside would petrol fuel problems cause a problem as I refilled with a tenners worth last week at a Garage that had "Ran dry" the day before? Hence my reason for the new filter.

So the problem continues.

 

[tdh-syorks]

hi steve this is from when mine was playing up, have a read and ill try and find a pic of the area i meant
http://www.mbclub.co.uk/forums/engine/117804-w203-m111-engine-misfire-stall-when-hot.html

 

[tdh-syorks]

right just above the airbox i have circled the cover in yellow. the cam sensor is behind the airbox so i think you might be better removing this too.
just disconnect from mass airflow sensor and the airbox just pulls out.
once the cover ive circled has been removed too you'll see the sensor

http://i422.photobucket.com/albums/pp306/tdh-syorks/DSCF0028-1.jpg

 

[Steve Holland]

this is my engine I think we were jousting pictures, it would appear they are slightly different? The area I have removed is top black plug and the cover (three allen bolts) that it plugs into.

 

[tdh-syorks]

Right, the part im on about is right on the front of your block. Its that black round part with a plug in it, that's what was leaking on mine, the plug just below it was the one full of oil.

 

[Steve Holland]

The top one has been cleaned out and the plate removed and cleaned inside, no oil leak evident but very dirty.

The lower black plug that goes into what looks like the coolant system is totally dry and the seal intact.

Sadly looks like the problem lies elswhere

Thank you for freely giving up some of you time this Good Friday Tom much appreciated buddy.

Looks like I'm gonna have to search a little more...........seems a few people that have had a missfire this week.

 

[tdh-syorks]

No problem, glad to try and help.

 

[NW_Merc]

On the M111, if its leaking into the gulley where the plugs are in the top of the cam cover, you may need new plug seals, otherwise the oil will leak into where the plugs sit. I dont think they're that expensive but then Ian Walker from 124works did mine a while ago before I started servicing the car myself.

You will need to remove the cam cover and take a look at the seals and see if they've perished.

 

[Steve Holland]

I checked the gulleys where the plugs fit in and they where very clean and dry, no oil. The plugs where obviously old but otherwise clean and apart from the wet sooty looking no 2 plug appeared in good order.

 

[NW_Merc]

In that case I'd get the fault codes read by someone with Star diagnostics preferably.

It could be any of a number of problems:
1. Mass Air flow Meter (MAF) issue
2. Plug leads
3. Coil packs
4. Spark plug gaps or fouled plugs
5. Oxygen (lambda) sensor fault

You really need to have the codes read otherwise it will be a very expensive bill which may not remedy the problem. Take your car up to 124works in Kirkham, Ian has star and should diagnose it for you.

 

[Steve Holland]

Ian has kindly done some work for me before, however I don't want to risk a drive that far in it's present state for fear of further damage assuming I will actually get there.

If I have to get it on a diagnostic (bearing in mind it does not have a very hi tech system on board - as advised at 124) then is there anyone that can advise of somewhere reasonable in the Manchester area.

Alternatively any other ways of problem solving.

The plugs are new and gapped correctly.

I can see no visible problems with the leads and they are all attached correctly and undamaged

Where is the Lamda sensor situated as I have had difficulty locating it and is it easily played with?


I will see if I can swap the coil packs around tomorrow to see if that may be the cause.

Anyone think it may be an injector blocked?

 

[tdh-syorks]

Lambda is screws into the exhaust before the cat, you won't be able to tell if anythings wrong with it by looking. Has your car flagged up engine management light??

 

[Steve Holland]

No lights of warning anywhere, no strange looking coded numbers ( I don't think I have that facility on my dash - there is another thread elswhere about that though ).

As I said car started exactly as it had always before and just ran with an apparent missfire and lumpy lunging power.

 

[mauno]

steve do you have access to sds?

 

[NW_Merc]

Could you get it recovered? I'm sure if you explain to your breakdown service that it's running like it is and you dont want to risk further damage they would take it?

As Ian is the closest and he's done work for you before, I'd take it there. Either way you look at it, the car needs proper diagnosis and you'll have to attempt to drive it anywhere to get it looked at.

 

[mauno]

I think his quite right

 

[Pendragon]

Had this same problem for the last 2 weeks until today. I had replaced coil packs, leads, plugs and both 02 sensors and it still run ragged. By chance I checked the breather pipes....both blocked and full of grunge. Cleaned them out and it is now running fine so before spending a shed load of money like I did go and take the pipes and plates off and give them a good clean and make sure air is getting through. Hope it helps and hope it cures your problem.

Keith

 

[Steve Holland]

Well cleaned the pipes and not a lot of muck in them, I am working away this week so using the better halfs car as a replacement. 5 days of tinkering and no joy but it does seem to be wanting to run on four cylinders this morning every now and again. Haven't swapped the coil packs yet but suspect it may be a fueling problem somewhere?

Once again anyone know if it is easy to check the injectors. Will leave it to soak in some redex for the next few days.