s-350d

Hey guys, the project gl350 is getting to be a tough cookie lol.

So, i purchased this guy about 3-4 months ago. It had many issues including the swirl flap motor failure and airmatic issues. It was serviced all its life at the local benz dealer. Multiple owners. The previous owner just had about $5000 of work done and the swirl flap and airmatic failed, so the owner decided to sell. I saw it at the benz dealer, and did a few checks. I knew it needed work and wanted it as a project, so i bought it. 182,000 kms.

I realized after i brought it home that the exhaust stunk like raw diesel. It smelled a lot different than our ml320 cdi (2008). This smelled like unburnt diesel and burns your eyes and throat. I repaired the air suspension with a fuse, bypassed the swirl flaps and opened them in the open position, did a full emissions delete/egr/swirl flaps with malone tuning. Got rid of the dpf but left the cat in. I figured the smell may have been the adblue dumping in or something, but after the delete the smell is still there.

Onto my current problem,

It is winter here, so temps are -10 to -20celsius on average. The vehicle starts up great, starts right up. Idles fine. No weird or odd noises. For the first few seconds, the exhaust smells somewhat normal (maybe), like a diesel. While its idling after 15-20 seconds, the exhaust starts to come out as white smoke, and smells like unburnt diesel/raw diesel. You can't stand behind the vehicle because it burns your eyes/throat. I thought it was condensation at first, but it smells weird. It has a bluish whitish tinge to it, kinda grey at times and hazy looking.

If you let it warm up for 10 minutes for example, the smoke is still there/a bit less. If i rev it, it clears out. If i drive it, it clears out. Also, if i rev it in neutral, it will stumble/miss around 2500 rpms, and puff bluish diesel smelling smoke out. Once it stops stumbling, it can rev to limiter at around 3000 i believe and blows constant bluish smoke. It doesnt smell as diesely, kind of acrid but still burns yours eyes and throat badly. Once i let off the gas and let it idle, it will continue to puff bluish smoke. It will slowly lessen and lessen until the smoke disappears completely.

When the engine is at operating temp and idling, no smoke at all. Until i rev it and it stumbles (diesely smoke), or full throttle in park revving and it will smoke. And again, i can let it idle and the smoke slowly goes away.

It will sometimes smoke when driving hard, but not all the time. If i'm heavy on the throttle, i notice it smokes more. I don't see any smoke when driving normally.

Also, i noticed if i let it idle for a while, rev it. It will stumble around 2500. If i "clear it up" by revving and immediately rev again, no stumble. Let it idle for a bit and try to rev again, it will stumble a bit around 2500.

What have i done so far?

I have taken all 6 injectors out and sent them out of town for testing. They cleaned the injectors, and tested them. They said "apart from higher than normal back flow", they have no issues. They passed. So, i reinstalled them with new copper washers and new stretch bolts.
I checked the air filters. They looked like they had never been changed. Dirtiest air filters i've ever seen. I replaced them.
Fuel filter looked like it had already been replaced with a MANN unit.
Swirl flaps were in the stuck closed position, so i tied them up in the open position.

My symptoms remain the same.

I need help as to what it could be. I do not have access to a star to check things, and it seems quite pricey to buy. I do have access to an autel scan tool from a mechanic friend who says he will lend it to me, but i don't know how in depth it will go.

I was thinking to check to see if the pcv valve is letting oil through, or if the egr is stuck open. Would a stuck open egr cause smoke? Even though its deleted and unplugged?

I have some videos of the smoke i will post.

Some values that may matter or show something that i noticed were:
EGR Error: -100% at idle, and as i revved it would go up to about 95% and back to -100% on idle
Fuel injection timing: About -5 degrees, up to 11 degrees on rev, and back down to -5 degrees on idle
Fuel rail pressure at idle: 31190 kpa
Air flow rate from mass air sensor: 19.11 g/s

Extra notes:

I sometimes get a diesel exhaust smell inside the cabin. Cannot tell where its coming from. I feel like i MAY have a boost leak somewhere, but i'm still investigating.
I feel like it doesn't have enough power. It certainly is not as fast and powerful as our ML320 CDI. I don't know if its because it is a lot heavier than our ML, or its just down on power.

Any suggestions are appreciated. If i give up, i MIGHT drop it off at a local diesel shop just to get it diagnosed.

Does anyone know how to check to see if the pcv valve is letting oil through. Or checks to make if the turbo seals have failed?

Thanks!

s-350d

This is the bluish whitish diesel smelling smoke.


Missing causing smoke when revving. Smells diesely. When you hold it at max revs, it smells more acrid but still burns your eyes and throat. You can hear it start to miss at the 20 second mark, and when i rev and let off constantly from there onwards. It emits that bluish whitish smoke that smells like unatomized diesel. It DOES NOT miss while driving.


Smokes gone. ITS MAGIC

rapidoxidation

Injectors.
"apart from higher than normal back flow"
There's your tell.
Well, aside from all the unburned (lousy spray pattern) diesel coming out the exhaust.

s-350d

Thanks for the reply!

​​​​​Would a leak off test show me any results? I know what i need to do this test, but what kind of results would i be looking for?

The shop that did the injector test told me over the phone that the results they had on the injectors would be showing longer cranking/hard starting. I told them the vehicle starts right up and that the only issue i had was smell and smoke. He was unsure of what to tell me, and with the results they got, i shouldnt be having that issue. It may have been because i was speaking with a shop advisor and not the technician.

Thats the only reason i reinstalled these injectors as i want to be 100% sure before i spend what would amount to $3500 on 6 injectors.(rockauto is showing me $567 each before taxes).

I will attempt to borrow my mechanics scan tool to see if anything odd shows up on there as well. I was still iffy on the injectors as im still thinking one or more is wonky. Just a feeling i had, but i do still want to confirm it before moving on rather than throwing parts at it.

Thanks for the reply!

B34chBum

CarID.com was the lowest I could find recently (this is for the earlier CDI injectors but the part may carry through 2010, not sure):
https://www.carid.com/bosch/common-r...986435355.html
($257 + $50 core deposit per injector)

Find out the Bosch reman number for the bluetec motors, then search the stores.
Yes, confirm before throwing money at parts!

s-350d

Thanks! Yeah i assume thats american as im up in canada but ill have a look at that.

Are remans any good? Rockauto shows bosch remans which work out to about $300 after cores.

John1979

Hi, I was just wondering if you ever managed to fix this problem? I have the same kind of smoke and am running out of ideas on how to fix it. Thanks.