High Idle, White Smoke, shifting funny, HELP!! 75 240D - Page 2 - PeachParts Mercedes-Benz Forum

Stretch · #16 10-03-2011, 03:45 AM

If you have an IP with a pneumatic governor then you should have a little mushroom air filter on top of the IP, (a pull to start knob in the cabin?), a separate lubrication system from the engine, and a venturi butterfly system that is attached to the throttle with a pipe that goes to the top back end of the IP.

The vacuum created by air rushing through the venturi butterfly valve controls the pressure on one side of a diaphragm in the IP. The other side is vented to atmosphere. From my understanding of the information in the (W123) FSM if there is a problem with the butterfly venturi set up (or the diaphragm in the IP) then a spring in the IP will tend to pull the gubbin's inside towards the full throttle stop. The engine will then race...

Ronkat81 · #17 10-03-2011, 09:16 AM

LOL no law or ex's, well maybe a couple of ex's lol... I'm in Eastern NC... I will def post some video's today and link them here. I did three yesterday and will upload them to youtube shortly. I do think that there may be more than one issue going on. @Kerry You are keeping me in good spirits about the head gasket!! the vids should be up in a couple of hours. @Army No I don't have the one from Mercedes. . .probably would be a wise decision to get one....

Ronkat81 · #18 10-03-2011, 09:21 AM

Quote:

Originally Posted by Army

If you have an IP with a pneumatic governor then you should have a little mushroom air filter on top of the IP, (a pull to start knob in the cabin?), a separate lubrication system from the engine, and a venturi butterfly system that is attached to the throttle with a pipe that goes to the top back end of the IP.

..

Yeah I have eveything except the air filter thingy.. I've seen the ones that do but mine doesn't... hopefully the video will be up soon

billhard · #19 10-03-2011, 11:43 AM

I am certainly not the expert here but have you considered the diaphragm in the injection pump may have failed? That might explain the smoke, oil from the IP entering the intake, and the idle issues. The plastic line from the back of the IP that connects to the intake manifold would show signs of oil having passed through it. I understand this is a common issue on the 616.916 and medium difficulty for DIY repair. I will PM you a link to downlaod a copy of the Factory Service Manual, it's a big file. In the mean time here are a couple pages to read over.

Don't forget the IP has it's own oil supply if you are in fact burning / loosing oil from the IP it may be low.

IP diaphragm

Idle Adjustment

kerry · #20 10-03-2011, 12:00 PM

Quote:

Originally Posted by billhard

I am certainly not the expert here but have you considered the diaphragm in the injection pump may have failed? That might explain the smoke, oil from the IP entering the intake, and the idle issues. The plastic line from the back of the IP that connects to the intake manifold would show signs of oil having passed through it. I understand this is a common issue on the 616.916 and medium difficulty for DIY repair. I will PM you a link to downlaod a copy of the Factory Service Manual, it's a big file. In the mean time here are a couple pages to read over.

Don't forget the IP has it's own oil supply if you are in fact burning / loosing oil from the IP it may be low.

IP diaphragm

Idle Adjustment

That's a really good hypothesis. I didn't know there was a diaphragm like that in his IP which is why I went for a failed vacuum pump diaphragm instead. I think you're on to something. It would explain the smoke when he backs of the accelerator which would produce high vacuum in the intake manifold with a butterfly valve.

Ronkat81 · #21 10-03-2011, 09:11 PM

Thanks Guys. . I will Def check that out.. I did disconnect that line and tried various amounts of suction and pressures on the line but the engine speed was unaffected. there was suction coming from the intake on that line though. On the first cylinder (The one closest to the fan) there is some leakage. I havent been able topinpoint ecatly where it is coming from. You will be able to see the wetness on the video around that injector. I am about to post the links to the videos on youtube

Ronkat81 · #22 10-03-2011, 09:19 PM

These are the Vids
Thanks for watching guys...

Ron
240D white smoke, high idle - YouTube
240D White smoke high idle part 2 - YouTube
video-2011-10-02-18-33-04 - YouTube
video-2011-10-03-09-57-58 - YouTube
video-2011-10-03-10-08-43 - YouTube

kerry · #23 10-03-2011, 09:47 PM

Video one looks like unburned diesel fuel to me. What's your air filter like. Have you tried running it with the intake manifold open to air while observing to make sure the butterfly valve is open?

kerry · #24 10-03-2011, 09:58 PM

The smoke when decelerating from high speed looks blue to me. I'd say the butterfly valve closing is producing a vacuum in the intake and it's sucking oil into the engine either via the PCV hose or the valve stem seals. You could remove the PCV hose, put it in a jug and drive it again and see if the smoke goes away upon deceleration.

kerry · #25 10-03-2011, 10:05 PM

In your 4th video, when you rev it up while sitting, sometimes you are getting unburned diesel--the really dark smoke and othertimes it's something else--the white smoke. Not sure what the white smoke is and I don't know what's producing your clouds of dark smoke unless the butterfly is not opening up.

kerry · #26 10-03-2011, 10:08 PM

Yeah, when you close the butterfly in the final video and the smoke turns dark brown, that is what was happening in the video just before. It proves your butterfly is not operating correctly in some circumstances. I think there are probably multiple problems combining here.
Personally, I don't know enough about that butterfly system to give any helpful advice except that I might try wiring that butterfly open all the time and see what happens.

Ronkat81 · #27 10-03-2011, 10:32 PM

Hmmm interesting... I'll try that in the morning.. The air filter is the oil bath kind... I did run it with the air filter disconnected and it still ran fast but idk about the anyone..i didn't pay any attention to it.. I will report in the am! Thanks Kerry!

Ronkat81 · #28 10-04-2011, 12:39 AM

Smoke not "anyone"

katja · #29 10-04-2011, 01:07 AM

I'll be watching this thread with some curiosity. I have similar symptoms with my 240D, though to a much lesser degree. I suspect that the diaphragm in the injection pump is torn or otherwise leaking. Yours is probably at a more advanced stage.

I have seen several 240D's like ours billowing smoke at idle - severe amounts of smoke - I believe that's when the diaphragm is completely torn.

Mine usually idles normally, though perhaps a little higher than it should - but will idle fast after a long, hard hill climb, and slowly returns to normal. Yours sounds like mine would when the idle adjuster on the dash is cranked all the way up.

I always have some bluish/grey smoke at idle, and pretty big puffs if I rev it...and I too get the big cloud of smoke if I let off the accelerator quickly at speed, or between shifts (mine's a manual transmission).

Does anyone have a suggestion of where to take one of these pumps to be repaired/rebuilt (mine also leaks some oil)? Maybe a diesel shop that does the Bosch pumps on trucks (i.e. Cummins) perhaps?

Stretch · #30 10-04-2011, 03:04 AM

Quote:

Originally Posted by katja

...
Does anyone have a suggestion of where to take one of these pumps to be repaired/rebuilt (mine also leaks some oil)? Maybe a diesel shop that does the Bosch pumps on trucks (i.e. Cummins) perhaps?

That would be the second place I'd check out after speaking with the friendly chief mechanic at the dealer.

I don't have EPC access (I'm going to have to just suck it up and pay for it) but replacing the diaphragm in the pump doesn't look too difficult from the pictures shown in the FSM.