deeepsix

Hi All,

Big fan of the forum and appreciate all the help it's been already. I searched for this topic but cannot find any similar issue.

I just completed re-assembly today after doing the oil cooler seals on my wife's 2010 GL350 - X164 OM642 Bluetec.

Upon initial startup, the nut on the passenger side of the rigid fuel line that connects the two fuel rails was loose and spewing diesel and there was heaps of smoke.

Stopped engine, tightened nut, started engine and went for a short test drive (~2 miles, maxing out at 45 MPH).

Returned home to find excess smoke still in the engine bay. I thought maybe this was excess fuel from the loose line so I used my air compressor to blow all areas out and hope to blow out any residual fuel.

Test drive #2 was about 5 miles in total distance, maxing out at 55MPH. No issues with performance, everything seems to be functioning/running smoothly.

Returned home, pop hood, still have excessive white smoke. This smoke is only in the engine bay, I have no issues with smoke at my exhaust tips.

I cannot figure out where this is coming from. I believe all bolts are properly torqued and doesn't appear to be an exhaust leak from any of the turbo/exhaust/EGR connections. I did reuse both of the metal EGR elbow gaskets.

The smoke doesn't seem to be constant. Appears white and I feel like there is a diesel fuel smell but am not certain. This was NOT an issue before doing the oil cooler seals. After that much driving and air blown through all areas, I wouldn't think there is still residual fuel sitting anywhere slowly burning off. Seems like it is cyclical but not distinct puffs which makes it nearly impossible to clearly see a source. I have found where people had bad injectors that allowed too much fuel resulting in unused fuel burning off but that seems to produce smoke at the back, not in the engine. I did not remove injectors during this repair - only removed the rigid fuel lines and fuel rails. Injectors were left alone.

Hoping to have some specific things to look at/for before I start tearing down again. Any help is greatly appreciated. Video is attached that shows the smoke. It appears at the rear end of the engine but cannot see where it's coming from.

Thanks.

Video cannot be attached for some reason- posted to youtube here:

deeepsix

Update - I see loads of views but no replies but I have resolved this so wanted to share.

I thought the smoke would not still be the fuel burning off but given that diesel fuel PSI is in the thousands, it would make sense that even just a few seconds sprayed heavy amounts of fuel which needed to burn off or be cleaned.

After some minor disassembly and further cleaning, there is no smoke. This must have been residual fuel that was sprayed out when the fuel rail nut was loose. I re-checked all fuel line nuts and fuel connections, used compressed air to blow out any residual fuel or residue of any kind and used some cleaner to be sure there wasn't anything left.

Re-assembled 24 hours later (this morning) and drove for a while and never had any smoke. What a relief.

dhurley

Diesel does take forever to evaporate and burn off. Glad its sorted.

deeepsix

I may have spoken too soon. After another drive today I felt like I smelled pretty heavy exhaust. This was with my driver's window down and slowly rolling through a parking lot and it may not have even been my car. I parked and popped the hood and the smoke is back, though not as heavy as it was yesterday.

However, this time it seems to smell like coolant (I THINK).

In doing the oil cooler seals, you have to drain some coolant out. When I initially re-assembled everything and turned to accessory power I got an "add coolant" message on the dash. I put nearly about 1.5 gallons back in and the system takes about 2 gallons I think. Should be good now so if I get this message again I'll know I'm losing/burning coolant somewhere.

Today I could see the smoke was clearly coming from the back of the passenger side of the engine, looked very close to the clamp that goes on the large elbow that comes off the back of the turbo (elbow bolts to turbo with 3 bolts and has a pipe clamp that connects to the rest of the piping).

If I am in fact losing/burning coolant - what should I look for in this area to determine where I have a leak? Intake manifolds are properly torqued and in the correct bolt pattern so don't think I have a leak there - plus a leak there would likely run down into the valley and through the weep hole that runs to the bell housing (like oil cooler leak).

Any thoughts on what I should look for? At this point I wouldn't think it's still residual diesel but it's a very small amount of smoke now. Want to get this sorted so appreciate any help.

dhurley

Triple check that your exhaust elbow at the turbo is tight on both ends.

deeepsix

^^ Are you talking about the main exhaust off the back of the turbo (3 bolts) or the exhaust manifold/Y pipe - 3 bolts on each end...

I just put it up on ramps and have to let it cool off. Got underneath it and still have a lot of oily mess where I had it before, but I think it's all "runoff" from the whole process and clean up because it's a very thin greasy residue. Feels like diesel with black oil in it so will clean this all up too and see what happens after the next test drive.

Lasnob

I have same problem, still waiting for your further solution if there is one.

carlosrg

I can't see to much take your shop air and shoot it around the back.. to me it seems to be coming off the turbo.. most likely the exhaust manifold to turbo. Did you use all new seals?

Also what is the smell.like?

Lasnob

It smells like diesel fumes on the exhaust. Only intercooler seal that i re-used it