I recently picked up a 98 e300 with 175k miles. The car slowly started to show more white smoke and air bubbles in the fuel lines. I went ahead and replaced the prefilter and all of the lines with new mercedes ones.

Now, the car starts fine but has a steady stream of light white smoke at idle. When you hold the throttle at about 2500 rpms it puffs a large amount of white smoke out. I watched the new lines while revving it and the one line from the lift pump to the SOV has air bubbles at anything above idle. How is the air still getting in? Is there an oring I missed somewhere?

Thanks

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Are you loosing coolant? Is it idling smoothly? How does it run?

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Jim

No coolant loss, it seems to run fine. The idle is loud and clanky but I wouldn't really say it's rough. It's much louder than my 87 om603. Once you bring the rpms up it seems to sound smooth and less noisy until it starts missing and white smoking at 2500 rpms.

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The idle on my 98 is also loud and clanky and I get grey/whitish smoke at idle especially if it sits idling for a while. I am pretty sure I need to install new injector nozzles.

Shine a laser pointer / pen on the clear fuel lines and you will see the air bubbles very easily as they travel through the other lines .
Tank strainer is usual culprit if air going into the lift pump , air gets drawn into line connections either at the tank end or where the rubber line joins the underbody steel line at the bulkhead .
Grey white smoke is lack of fuel / incomplete burn and in your case due to the bubbles in fuel.

I replaced the feed line to the IP since it was a little wet and dry rotted, this made no difference. I am still getting air in the line from the lift pump to SOV and from the SOV to the bottom of the prefilter. I don't even know what to check now, any ideas? It runs perfect on the road but has a light white smoke at idle and obviously has air in the two above clear fuel lines.



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Updating this again, I just had all 6 injectors reset for correct pop preasure and replaced with 6 known good nozes so there was no leaking.

It seems to do the exact same thing, I don't understand what's causing this after replacing fuel filter, dropped and cleaned the fuel strainer in the tank, all new fuel lines around the IP, new return lines for the injectors and a new rubber supply hose from the firewall.

It runs perfectly fine and start good but it smokes white and misses bad if you try to maintain a higher rpm while idiling or while your driving with light throttle it surges and misses. It has plenty of power at full throttle and doesn't miss a bit. What am I missing here?



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Does anybody have any ideas on this? Could a sticky EGR possibly cause this? It runs so good and smooth I can't imagine it being anything big, only partial throttle it starts missing and smoking badly but full throttle it runs perfect with no smoke.

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Compression test!

Before you even start a compression test crack the injector lines, the cylinder that doesn't respond is the problem.


Also the problem cylinder will clear up your smoke.

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1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

There is an o-ring behind the SOV.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

I went ahead and replaced the oring behind the sov since I haven't done it yet and saw no change. Also, I broke loose each injection line at a time and each one showed a noticable change in sound. I took a video of of it running with the intake manifold off wanting to verify there was not white smoke coming out of the intake valves which there wasn't. I'm lost with this other than a compression test, I just don't understand why it runs so well without smoking at full throttle but it has a steady white smoke at idle even when warm and misses until around 4k rpms. What's weird is when your driving it has no miss even at low rpms as long as your giving it more than about 20% throttle, but at low rpms and light throttle it surges and smokes. The link is below, let me know what you guys think.

https://youtu.be/rnL_Jt9T8f0



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White smoke can also be oil leak in turbo.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

I'm thinking possible turbo as well.. I had to replace the turbo on my om603 white smoke. It clearing up under full throttle kinda gets me though.....HMMMM

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Live simply so others can simply live



07 E350 sport Wife's Daily
01 E320 sport My Daily
00 C230 Kompressor Our back up (new Arrival)

87 300D Turbo my Daily for 8 yrs. Selling to neighbor

82 GMC Jimmy (K5) 6.2 Diesel (my Wheeler)
73 Roadrunner 340ci My very first car, still own it

It's definitely not pushing oil through the intake, although when I bought the car the lady told me she just had the local Mercedes mechanic replace the turbo with a used one. I'm not losing any oil either, watching the video you can definitely see the misfire.


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That's odd, I swear I thought I saw smoke coming out the intake. Another weird thing is your Om606 is quite loud, it's has a lot more chatter than mine.

This looks similar to the problem in my SDL, the missing and smoke.

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.