I don't know how you came up with the assumption that I ignored everything everyone said, I intend to do a compression test but was checking all other easier options first and wanted all the information I could gather. I just replaced the injectors with rebuilt ones and need to order new heat shields and an adapter to test compression. I have records of a compression test very recently before I bought it with perfect results, it didn't have these symptoms and it just started one day and slowly progressed to what it is now. It has zero blow by which I would expect to see with a cylinder losing enough compression to cause an issue like this.

I will do a compression test again soon and report back, I know things can happen at anytime and I can't rule it out.



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If replacing the injectors didn't change the running behavior, it's probably safe to say you can rule them out as the source of your problems.

Blowby is caused by combustion gas leaking past the rings. Compression loss through valve problems is far more common. If you have worn valves or worn valve stems, you have have enough slop to leak enough compression to cause running problems. Compression loss via valves failing to seal would not cause blowby. White smoke is unburnt fuel. The missing out with the white puffing suggests that fuel is being injected but not burnt.

A compression test will tell you if you have compression problems. A leakdown test will tell you how severe it is and where the leak is occurring (listen for the air leaking out).

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Does it still have air bubbles in the fuel lines ?

It does, it was even worse with the fuel pump I added inline.

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The source of bubbles needs to be found and eliminated. There should be 0 bubbles anywhere in the fuel lines. Air that gets into the injection pump can and will cause injection problems and can accelerate wear to the pumping elements.

Take a strong light and put behind the clear lines and see where the bubbles show up. If you can find a place where there are none, the place they show up is your culprit. The 606 has an extremely stupid fuel supply system that's notoriously difficult to stop leaking on. One forum member recently had air ingress that they couldn't seem to solve and turned out to be the fuel heat exchanger was cracked just enough to let air in, but not fuel out.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

You can have a compression loss between adjacent cylinders or out of the Engine entirely due to a head gasket leak and or past the intake and exhaust valves (more common with the exhaust valves). None of those would create blow-by.

__________________
84 300D, 82 Volvo 244Gl Diesel

Assuming you get the white smoke at idle you could remove the Fuel Inlet Hose and get a separate hose and run it to a container or clean Diesel Fuel and see if the smoke stops.

If the smoke stops you know you have a problem in the Fuel Supply System from the hood back.

I have not followed this thread closely. Was it determined if the smoke smelled like fuel, oil or coolant?

__________________
84 300D, 82 Volvo 244Gl Diesel

10X on getting air out of the fuel system.

One test I did is use a short length of 3/8 clear hose and 3/8 male/male barbed coupler (find these at your local hardware store). Connect the clear hose to the hardline from the fuel tank on the firewall and connect the coupler to clear oine and fuel hose going to the fuel thermostat.

Start the car and if you see bubbles you know where the problem flies. HTH.

I finally narrowed down my bubbles to the fuel thermostat, which at first I never considered changing, and wound up replacing it. There is a gasket between the plastic top and the aluminum bottom of the thermostat that I think was leaking air. Fuel bubbles gone.

I got the heat exchanger to pre filter to quit getting bubbles, but the one from the pre filter to the SOV has a ton of bubbles. I took it off and checked the orings and it some silicone on and it still have bubbles. Would the be the first source of the air since it's the next in line?



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I have the same problem. I have occasional air bubbles going from the bottom of the prefilter side of the assembly to the top of the shut off valve. I would think it would either be the o ring at the connection of the line to the prefilter, the o ring on the prefilter, or the o ring on the line out of the prefilter. All the lines and prefilter o ring was replaced on my car not all that long ago but I will probably replace them again. I also have bubbles on the clear return line out of the IP. I wonder if the main filter could be the cause but I would think not if its coming out of the prefilter side.

Any update?