M49 1.9 diesel misfire and clattering noise...

[Jane Rushby]

Have trawled through other threads of similar symptoms and egr keeps cropping up. Never had the misfortune to have a modern diesel run rough before, so it's all news to me.
W reg multispace been stood 3 or 4 years. I never really liked the new dangled thing, as it was slower and less economical than older French cars with similar engine size I've had . Anyway I digress.

 Symptoms were, slight intermittent "stutter" usually around 1500 rpm.... Changed filters filled with new fuel and chucked in a bottle of magic fluid. ( This might be the big mistake, label has fallen off so don't know make or dosage. But it is definitely fuel cleaner of some kind rather than glue.)

Symptoms now.... Starts and ticks over perfect for first 100 yards then misfires violently under load but doesn't stall. Occasionally alarming mechanical rattling noise starts and then stops when throttle off .

It will trundle along at 1200 rpm in any gear and, if it doesn't make the clattering noise and there's an empty road it bowls along fine over 2500 rpm. 

Maybe relevant ... Fixed rear exhaust box on to pipe better, no fumes in car but feels like a lot of exhaust pressure and strange exhaust note. 

This is the confused hubby, btw, I thought Rover 75 clutch was the epitome of frustration....

Thanks for any other pointers,

[divingdad]

Could there be an obstuction/part obstruction somewhere along the exhaust? Having been stood for so long maybe a mouse has nested up there?

[Jane Rushby]

Could there be an obstuction/part obstruction somewhere along the exhaust? Having been stood for so long maybe a mouse has nested up there?

Quite possibly, that has crossed my mind, according to witnesses there was debris blown out when I revved it up. Evidence of vermin under the bonnet.

Just had another test drive, in case the faeries had worked on it over night. Between approx 1200 and 2200 rpm in every gear, under load, there is only hesitation and gloom. outside that range is "perky and cheerful get up and Vroom" So, on the exhaust theme, Im thinking some new fangled emission sensor thing...EGR? Lambda?

[jj9]

Possibly the EGR valve jammed open, look for info on removing and cleaning it, also look into blanking it off.

Has the oil & filter been changed since you brought the car out of hibernation?,  if not I would do that as a priority.

I would also want to give the car a decent run fast run of 20 miles or so on a motorway to get it up to full working temperature and to clear it out.

[Jane Rushby]

As this car has only ever had professionals under the bonnet, except for my recent fuel and air filter change, we have nearly decided to take it back to the garage we bought it from for diagnosis, rather than poke about in the dark. It is a Citroen specialist of good repute and old school values. Unless there is someone else between Lincoln and Grimsby who has the fabled gizmo for reading fault codes....
On the subject of possible exhaust blockage...found a walnut sized lump of hard black substance rattling around in the back box. Report back when had test drive.....

[jj9]

As the car has stood for quite a while maybe the exhaust baffles have rotted away inside, hence the pieces coming out and the different exhaust note mentioned earlier on.


.

[ricc]

we used to get an intermittent rattly sound from our 1.9d , usually just after start up,  one day it did it on the way back from shopping, rattly under load and lack of power.... theres a few thin plastic pipes arround the injection punp area , looks like it could be some sort of vacuum advance /retard system anyway one was split ,  taping it up cured the power loss and  we havnt heard the rattles at all since.

[Jane Rushby]

Well, thank you everybody. Gave it a good thrashing , as recommended, which made things a bit better.
Tried whipping off the rear silencer and trying it without. Blimey! My cap fell off my shiny head, the g force was so strong.
replaced silencer loosely, due to losing one of the clamp bolts, and we have a nice balance of raw power, slight pleasantly burbling sound and no fumes. Brilliant car! Love it!

[ron]

Glad your wallet didn't get a bashing.

[geoff]

.... My cap fell off my shiny head .... ... Brilliant car! Love it!

Ah the husband is a convert now ....................................