Volvo d13 2012 water separator is black after 3000 miles driving wath can be the problem

I had it at Volvo yesterday and they tested the cups and injectors. Just called and said they were fine, no issues. Maybe the fuel system, but would that be intermittent? I was just looking for some ideas to narrow it down. Maybe wait a few weeks and see if there is any changes.

 

Algae? Are the insides of the tank clean? Have you shocked it recently?

 

The drivers side yes, the passenger side no, some stuff in the bottom of the tank. Algae I don't think so. Doesn't look look like it. I will buy some biocide?? and see if that helps. Unfortunately everyone is closed up for the long weekend till Tuesday so it will have to wait.

 

What tests did they perform should be the first question.....some mechanics don't really have the concept of where(and how) the leaks come from and what to test.

It wouldn't be the first time a mechanic misdiagnosed an injector cup leak.

This just happened to one of my friends recently and he had to have the truck towed from Vermont back to Pennsylvania because of it.

Now they're doing the cups finally.

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Air test they called it, they did not pull the valve cover. It is more time if they pull the cover off and the mechanic and service advisor said if there was an issue would have advised going further. Had an oil sample taken just in case. Will see what happens.

 

Yeah most mechanics aren't diagnosing correctly because they don't understand that cups leak in many ways.
A common one is deformation that causes the copper sealing washer to leak. This allows combustion gasses to pass the injector nozzle and shoulder, going into the inside of cup with the fuel.

If the injectors got pulled you will see if they are leaking.

You can also put clear hose on fuel supply and return lines... Look for air coming out without any going in.

 

2012, 340000 miles, 5 sets of injectors. Apparently they know they have a problem, geez really???

 

I don't believe is caused by injectors, I replaced all 6 few weeks ago, especially for this reason, i didnt have long cranking isues; I replaced my water separator and fuel filter 3 times ,still getting black . One explanation I got from Volvo , was that the fuel with high % biomass content, gets fried in contact with hot area in injectors/head and return
contaminates the rest of fuel in tanks. Another cause i read is hold down bolts stretch and lift up under pressure or rubbery fuel lines decomposed .Does this happen to newer low mileage motors?!

 

Injector hold downs let the injector get pushed up by cylinder pressure... especially with the junk, soft stainless cups that deform at the copper washer sealing surface.
New injectors can do this right out of the gate if cups installed wrong or incorrect torque was done on hold downs.

The black fuel from high heat is Asphaltines.... Not common on Volvo motors unless operated in very high heat like southwest summer I-10 and/or frequently operated at low fuel levels.



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Thanks for your help. I was away for a bit, no cell service(which I prefer sometimes). I haven't driven the truck much but will look for air in the fuel tank. Have been south to California and Arizona in the hot and yes that does match with what you said. I still am not sure, truck started normally this afternoon and started the same all afternoon. Not sure whether I want to spend the money to pull the injectors yet and test them. Which seems to be the only way to be sure. The problem isn't serious yet I think. I appreciate your help on this, yours and qualitytruck have been a big help. I will post if there are any changes and what happens. I think others are having the same issue.