C220 D Uneven Idle when hot

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Pajo_16

New Member
Joined
May 11, 2009
Messages
8
Location
Belfast
Car
MB C220 D W202121 1998
First, thanks to all for the years of support this forum has given me without even having to create a post!!!

This time a post may be needed!!!

I have a problem with my Mercedes Benz. When I drive for period of time, say 30 minutes, any point I have to come to a stop there is a high probability that the car will begin 'hunting' and most likely cut out.

I spoke with a diesel specialist from Omagh who recommended against getting the injectors rebuild and recommended instead that I replace the two clear diesel pipes entering / exiting from the diesel fuel filter housing first.

I purchased the two pipes last Saturday from the dealer in Belfast. I just picked them this morning and fitted them 20 minutes ago.

I will let everyone know how I get on.

The part number I purchased were:
A 604 070 04 32 - £11.80 + VAT
A 604 070 05 32 - £11.40 + VAT

Here are some pictures of the old and new hoses:
https://goo.gl/photos/xsEu5iAqtVAWDfsf9

:thumb:
-----------------------------
Mercedes Benz Model:
WDB2021212F7286xx
C220 D
2155 CC
 
Thanks Erfan for the advice. I failed to mention that I already tried this; I bought the maf sensor cleaner for £10 but it did not work. I did notice that the remind sounded smoother!!

With the new clear plastic pipes on my W202 I can now see the diesel in the pipes. When the car started to run rough on Monday, three days ago, I pulled over and looked at the pipes. I could see that the clear pipe from the filter housing to the pump had a stream of air bubbles; but no bubbles on the supply from the tank to the filter housing.

Bingo.

So I have air getting in around the filter housing.

This weekend I will investigate further. I replaced the oring when I changed the diesel filter about 2,000 miles ago.

I might have a filter housing crack, but that is speculation / opinion which I hope to invalided with some facts on Saturday when I get to investigate!!!
 
PS. I added a video of the bubbles in the house to the album in the opening post.
 
I think I found the source of the air in the fuel lines. I replaced the two hoses joining the metal lines coming up from under the body to the pump and engine fuel heater.

Pictures:
https://goo.gl/photos/Xg6rpnFwPy4dnpD58

The two hoses (I think) were:
Item 65: A 2024764326
Item 83: A 2024767126

I'll be driving to work on Monday and hopefully it won't start drawing air!!! Will post an update then.
 
Help needed!!!

There has been no difference in the level of air in the fuel lines, with all the fixes above I still haven't fixed the root cause.

I can still see air in the hose that runs from the fuel heater to the fuel filter housing.

Does anyone know where air can be getting in? I think it's back at the tank somewhere. Possibly the rubber hose number 41 on the attached picture A 2024766026 :
https://goo.gl/photos/HAc1Q7eotSDumeJ69
Source of photo: Àâòîçàï÷àñòè Ìåðñåäåñ. Îðèãèíàëüíûé êàòàëîã mercedes - Ëåãêîâûå àâòîìîáèëè

I might remove the rubber hose attracted to the steel fuel pipe in the engine compartment and try to blow air up the pipe... in the remote chance there is a blockage of some sort.

If that doesn't work, I'm going to have to find the rubber hose 41 on the picture above and try to replace it.
 
So I replaced all the rubber hoses, and as I said earlier the Mercedes clear pipes attached to the filter, and the problem is still there.

I can see air in the fuel lines.

I now believe that the problem is on the tank. I think there is a network of pipes in there and one of then is drawing air.

My plan now is to folklore the tank full of fuel to see if that is a workaround. If that works I might call by my MB Specialist to hear what they have to say.
 
So I replaced all the rubber hoses, and as I said earlier the Mercedes clear pipes attached to the filter, and the problem is still there.

I can see air in the fuel lines.

I now believe that the problem is on the tank. I think there is a network of pipes in there and one of then is drawing air.

My plan now is to folklore the tank full of fuel to see if that is a workaround. If that works I might call by my MB Specialist to hear what they have to say.


I would remove the robber hose from the hard line going back to the tank, connect it to a funnels and fill with diesel then try and start, if problem is gone, then you are correct air is leaking in further up.

Have you replaced all the O-rings on the push fit connectors? And the O-ring behind the shutoff valve on the IP? Literally the slightest leak on any of these will cause a no start problem.

I've bypassed the fuel heater, delete the mechanical lift pump, deleted the OEM filter and I'm installing an elec pump under the tank, feeding a big DAF filter housing and the direct into the IP.
 
Hi
what was your outcome for uneven idle on w202 16/02/2016 same problem to me
 
Not resolved yet. Car cuts out coming into roundabouts now!

I have a appointment with a my specialist next week. I bought two replacement VDO sensors so fingers crossed that will work. I am still convinced that the air is originating within the tank. Hopefully draining the tank and removing the sensors will give a better idea of what is wrong.

P's. I am changing the sensors anyway as my gauge started to stop at 1/4 full. Resulting in some near misses for fuel refill. I use the trip counter now to check for that issue. 600 miles per full tank.
 
I have change and check all pipes empty fuel tank try to open with different tool the ring holding sensor want turn will give second go this weekend try to move vehicle it cuts off EPC light comes on.
 
Decided to scrape w202121 epc light fault any 8mnths mot spent £300 before mot in feb2016 would not spent any money
 
c220d uneven idle epc lights spent enough might scrape

Hi All
I have used D900 no codes, used led tester changed brake switch idle switch and replace check all vacuum pipes did smoke test.

Need advice recently spent £300.00 prior to mot ans serviced can not find fault any help or might end to scrapeyard

Any advice
 
Codes are only half the info. Find a Star diag near you and someone that knows how to use it.
 
Hi
The car moves few yards and epc light comes on want move if any one wants any parts fill free to contact spent enough rather than scrape would sell parts cheaply to only club members, recently change oil, fuel filter calipers brake pads half exhaust by end of this weekend
 

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