S40 (New) Engine 2.0D : Black smoke with Sluggish acceleration in low gears

[Gremlin682001]

Hi All
Very confused defect occurring and wondering if anybody else has had same defect occurring ?
S40 2.0D no dpf 2005 D4204T. new egr, throttle body cleaned.
No warning lights illuminated. starts ok but with a definitive thump like an explosive detonation, mpg showing appx 50 mpg and sluggish acceleration when putting foot down, in 3rd-to 5 th gears with black/unburnt smoke being emitted(fairly big clouds of it as well) with the very occasional jerk/hesitation haven't got an obd2 reader but will get one once I work out the best/cheapest to get.
very grateful for any suggestions, my thought process so far is 1) vacuum hoses 2) map sensor 3) maf sensor 4) injectors 5) turbo ?

best regards David

[allanw]

Have you checked all turbo hoses? When you cleaned throttle body did you check Map sensor hole not plugged? Black smoke is too much fuel to air ratio so therefore check for boost air leaks. Hate to say but on mine turned out to be turbo and I had to replace it.

[Gremlin682001]

Hi. I’m going to have a good look around the engine bay over the next couple of days and I’m embarrassed to say that I didn’t check it wasn’t blocked when I cleaned the throttle, I’ll add that to the list. Thanks for your info, much appreciated

[allanw]

No problem. Don't forget to check all small vacuum hoses especially to turbo control valve. You could maybe do me a favour while you looking around and see where engine coolant temperature sensor connector wires run to? Sensor hidden behind oil filling pipe at the side of thermostat housing where top coolant hose enters. My sensor yellow in colour with black connector and two wires. Found my connector on the under tray with two broken wires attached. I don't know where it attached to wiring loom. I did an earlier post on it. If I can help any more let me know.

[Gremlin682001]

Brilliant, thanks for the help, I’ll report back when I’ve rooted about in the bay.
Cheers David

[Gremlin682001]

Hi All, after having a good look around the engine, I’m unable to find any hoses with cracks or not where they’re supposed to be, no wiring issues that I can see, I recleaned the two sensors on the inlet manifold which were a bit gunky.
I did notice however that my fuel air line after the filter had a large bubble in it and when I started it, there were lots of small bubbles coming through,
I bled and primed the system and got rid of those as far as I can see(used the Volvo pump) she seems to be quieter and with more acceleration through the gears, she still smokes on hard acceleration but is that left over remnants and could the cause have been that simple ?

Cheers David

[Gremlin682001]

Solved
All four injectors replaced and problems resolved. Injectors sourced from PF jones. Excellent customer service and prices. No connection just a very happy customer

[Gremlin682001]

hi all. An update on this issue. Well after changing the injectors a while ago which cured the issue. It reappeared a couple of weeks ago. Black smoke, unburnt diesel smell from exhaust, awful fuel eco and sluggish, not So that it was in limp mode but pretty poor.
Volvo couldn't find the defect. Vida/dice neither all parameters were in the expected zone. Gave up and was about to start looking for a replacement when a friend said.......have a look at the glow plug relay......and after a £30 part from Autodoc.co.uk in Germany....v reasonable prices btw. No relationship apart from a happy customer.
problem resolved.
Hope this helps someone who may be, like me driving themselves to drink with their car.

Cheers Gremlin